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NSCLC is any type of epithelial lung cancer other than small cell lung cancer (SCLC). The most common types of NSCLC are squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, but there are several other types that occur less frequently, and all types can occur in unusual histologic variants. Although NSCLCs are associated with cigarette smoke, adenocarcinomas may be found in patients who have never smoked. As a class, NSCLCs are relatively insensitive to chemotherapy and radiation therapy compared with SCLC. Patients with resectable disease may be cured by surgery or surgery followed by chemotherapy. Local control can be achieved with radiation therapy in a large number of patients with unresectable disease, but cure is seen only in a small number of patients. Patients with locally advanced unresectable disease may achieve long-term survival with radiation therapy combined with chemotherapy. Patients with advanced metastatic disease may achieve improved survival and palliation of symptoms with chemotherapy, targeted agents, and other supportive measures.
Incidence and Mortality
Estimated new cases and deaths from lung cancer (NSCLC and SCLC combined) in the United States in 2019:
Lung cancer is the leading cause of cancer-related mortality in the United States. The 5-year relative survival rate from 1995 to 2001 for patients with lung cancer was 15.7%. The 5-year relative survival rate for patients with local-stage (49%), regional-stage (16%), and distant-stage (2%) disease varies markedly, depending on the stage at diagnosis.
NSCLC arises from the epithelial cells of the lung of the central bronchi to terminal alveoli. The histological type of NSCLC correlates with site of origin, reflecting the variation in respiratory tract epithelium of the bronchi to alveoli. Squamous cell carcinoma usually starts near a central bronchus. Adenocarcinoma and bronchioloalveolar carcinoma usually originate in peripheral lung tissue.
Anatomy of the respiratory system.
Smoking-related lung carcinogenesis is a multistep process. Squamous cell carcinoma and adenocarcinoma have defined premalignant precursor lesions. Before becoming invasive, lung epithelium may undergo morphological changes that include the following:
Dysplasia and carcinoma in situ are considered the principal premalignant lesions because they are more likely to progress to invasive cancer and less likely to spontaneously regress.
In addition, after resection of a lung cancer, there is a 1% to 2% risk per patient per year that a second lung cancer will occur.
NSCLC is a heterogeneous aggregate of histologies. The most common histologies include the following:
These histologies are often classified together because approaches to diagnosis, staging, prognosis, and treatment are similar.
Increasing age is the most important risk factor for most cancers. Other risk factors for lung cancer include the following:
The single most important risk factor for the development of lung cancer is smoking. For smokers, the risk for lung cancer is on average tenfold higher than in lifetime nonsmokers (defined as a person who has smoked <100 cigarettes in his or her lifetime). The risk increases with the quantity of cigarettes, duration of smoking, and starting age.
Smoking cessation results in a decrease in precancerous lesions and a reduction in the risk of developing lung cancer. Former smokers continue to have an elevated risk of lung cancer for years after quitting. Asbestos exposure may exert a synergistic effect of cigarette smoking on the lung cancer risk.
A significant number of patients cured of their smoking-related lung cancer may develop a second malignancy. In the Lung Cancer Study Group trial of 907 patients with stage T1, N0 resected tumors, the rate was 1.8% per year for nonpulmonary second cancers and 1.6% per year for new lung cancers. Other studies have reported even higher risks of second tumors in long-term survivors, including rates of 10% for second lung cancers and 20% for all second cancers.
Because of the persistent risk of developing second lung cancers in former smokers, various chemoprevention strategies have been evaluated in randomized control trials. None of the phase III trials using the agents beta carotene, retinol, 13-cis -retinoic acid, [alpha]-tocopherol, N-acetylcysteine, or acetylsalicylic acid has demonstrated beneficial, reproducible results.[18,22,23,24,25][Level of evidence: 1iiA] Chemoprevention of second primary cancers of the upper aerodigestive tract is undergoing clinical evaluation in patients with early-stage lung cancer.
(Refer to the PDQ summary on Lung Cancer Prevention for more information.)
In patients considered at high risk for developing lung cancer, the only screening modality for early detection that has been shown to alter mortality is low-dose helical CT scanning. Studies of lung cancer screening with chest radiography and sputum cytology have failed to demonstrate that screening lowers lung cancer mortality rates.
(Refer to the Screening by low-dose helical computed tomography subsection in the PDQ summary on Lung Cancer Screening for more information.)
Lung cancer may present with symptoms or be found incidentally on chest imaging. Symptoms and signs may result from the location of the primary local invasion or compression of adjacent thoracic structures, distant metastases, or paraneoplastic phenomena. The most common symptoms at presentation are worsening cough or chest pain. Other presenting symptoms include the following:
Symptoms may result from local invasion or compression of adjacent thoracic structures such as compression involving the esophagus causing dysphagia, compression involving the laryngeal nerves causing hoarseness, or compression involving the superior vena cava causing facial edema and distension of the superficial veins of the head and neck. Symptoms from distant metastases may also be present and include neurological defect or personality change from brain metastases or pain from bone metastases. Infrequently, patients may present with symptoms and signs of paraneoplastic diseases such as hypertrophic osteoarthropathy with digital clubbing or hypercalcemia from parathyroid hormone-related protein. Physical examination may identify enlarged supraclavicular lymphadenopathy, pleural effusion or lobar collapse, unresolved pneumonia, or signs of associated disease such as chronic obstructive pulmonary disease or pulmonary fibrosis.
Investigations of patients with suspected NSCLC focus on confirming the diagnosis and determining the extent of the disease. Treatment options for patients are determined by histology, stage, and general health and comorbidities of the patient.
The procedures used to determine the presence of cancer include the following:
Before a patient begins lung cancer treatment, an experienced lung cancer pathologist must review the pathologic material. This is critical because SCLC, which responds well to chemotherapy and is generally not treated surgically, can be confused on microscopic examination with NSCLC. Immunohistochemistry and electron microscopy are invaluable techniques for diagnosis and subclassification, but most lung tumors can be classified by light microscopic criteria.
(Refer to the Staging Evaluation section of this summary for more information on tests and procedures used for staging.)
The identification of mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease. In particular, subsets of adenocarcinoma now can be defined by specific mutations in genes encoding components of the epidermal growth factor receptor (EGFR) and downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinases (PI3K) signaling pathways. These mutations may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors.
Other genetic abnormalities of potential relevance to treatment decisions include translocations involving the anaplastic lymphoma kinase (ALK)-tyrosine kinase receptor, which are sensitive to ALK inhibitors, and amplification of MET (mesenchymal epithelial transition factor), which encodes the hepatocyte growth factor receptor. MET amplification has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.
Multiple studies have attempted to identify the prognostic importance of a variety of clinicopathologic factors.[21,29,30,31,32] Factors that have correlated with adverse prognosis include the following:
For patients with inoperable disease, prognosis is adversely affected by poor performance status and weight loss of more than 10%. These patients have been excluded from clinical trials evaluating aggressive multimodality interventions.
In multiple retrospective analyses of clinical trial data, advanced age alone has not been shown to influence response or survival with therapy.
(Refer to the separate treatment sections for each stage of NSCLC in this summary for more information about prognosis.)
Because treatment is not satisfactory for almost all patients with NSCLC, eligible patients should be considered for clinical trials. Information about ongoing clinical trials is available from the NCI website.
Other PDQ summaries containing information related to lung cancer include the following:
Malignant non-small cell epithelial tumors of the lung are classified by the World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC). There are three main subtypes of non-small cell lung cancer (NSCLC), including the following:
There are numerous additional subtypes of decreasing frequency.
WHO/IASLC Histologic Classification of NSCLC
Squamous cell carcinoma
Most squamous cell carcinomas of the lung are located centrally, in the larger bronchi of the lung. Squamous cell carcinomas are linked more strongly with smoking than other forms of NSCLC. The incidence of squamous cell carcinoma of the lung has been decreasing in recent years.
Adenocarcinoma is now the most common histologic subtype in many countries, and subclassification of adenocarcinoma is important. One of the biggest problems with lung adenocarcinomas is the frequent histologic heterogeneity. In fact, mixtures of adenocarcinoma histologic subtypes are more common than tumors consisting purely of a single pattern of acinar, papillary, bronchioloalveolar, and solid adenocarcinoma with mucin formation.
Criteria for the diagnosis of bronchioloalveolar carcinoma have varied widely in the past. The current WHO/IASLC definition is much more restrictive than that previously used by many pathologists because it is limited to only noninvasive tumors.
If stromal, vascular, or pleural invasion are identified in an adenocarcinoma that has an extensive bronchioloalveolar carcinoma component, the classification would be an adenocarcinoma of mixed subtype with predominant bronchioloalveolar pattern and a focal acinar, solid, or papillary pattern, depending on which pattern is seen in the invasive component. However, the future of bronchioloalveolar carcinoma as a distinct clinical entity is unclear; a multidisciplinary expert panel representing the IASLC, the American Thoracic Society, and the European Respiratory Society proposed a major revision of the classification of adenocarcinomas in 2011 that entails a reclassification of what was called bronchioloalveolar carcinoma into newly defined histologic subgroups.
The following variants of adenocarcinoma are recognized in the WHO/IASLC classification:
Large cell carcinoma
In addition to the general category of large cell carcinoma, several uncommon variants are recognized in the WHO/IASLC classification, including the following:
Basaloid carcinoma is also recognized as a variant of squamous cell carcinoma, and rarely, adenocarcinomas may have a basaloid pattern; however, in tumors without either of these features, they are regarded as a variant of large cell carcinoma.
LCNEC is recognized as a histologically high-grade non-small cell carcinoma. It has a very poor prognosis similar to that of small cell lung cancer (SCLC). Atypical carcinoid is recognized as an intermediate-grade neuroendocrine tumor with a prognosis that falls between typical carcinoid and high-grade SCLC and LCNEC.
Neuroendocrine differentiation can be demonstrated by immunohistochemistry or electron microscopy in 10% to 20% of common NSCLCs that do not have any neuroendocrine morphology. These tumors are not formally recognized within the WHO/IASLC classification scheme because the clinical and therapeutic significance of neuroendocrine differentiation in NSCLC is not firmly established. These tumors are referred to collectively as NSCLC with neuroendocrine differentiation.
Carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements
This is a group of rare tumors. Spindle cell carcinomas and giant cell carcinomas comprise only 0.4% of all lung malignancies, and carcinosarcomas comprise only 0.1% of all lung malignancies. In addition, this group of tumors reflects a continuum in histologic heterogeneity as well as epithelial and mesenchymal differentiation. On the basis of clinical and molecular data, biphasic pulmonary blastoma is regarded as part of the spectrum of carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements.
The identification of mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease. In particular, subsets of adenocarcinoma now can be defined by specific mutations in genes encoding components of the epidermal growth factor receptor (EGFR) and downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinases (PI3K) signaling pathways. These mutations may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors. Other mutations of potential relevance to treatment decisions include:
These mutations are mutually exclusive, except for those involving PI3KCA and BRAF mutations, EGFR mutations, or ALK translocations.[3,4]
EGFR and ALK mutations predominate in adenocarcinomas that develop in nonsmokers, and KRAS and BRAF mutations are more common in smokers or former smokers. EGFR mutations strongly predict the improved response rate and progression-free survival of EGFR inhibitors. In a set of 2,142 lung adenocarcinoma specimens from patients treated at Memorial Sloan Kettering Cancer Center, EGFR exon 19 deletions and L858R were found in 15% of tumors from former smokers (181 of 1,218; 95% confidence interval [CI], 13–17), 6% from current smokers (20 of 344; 95% CI, 4–9), and 52% from never-smokers (302 of 580; 95% CI, 48–56; P < .001 for ever- vs. never-smokers).
Fusions of ALK with EML4 genes form translocation products that occur in ranges from 3% to 7% in unselected NSCLC and are responsive to pharmacological inhibition of ALK by agents such as crizotinib. Sensitizing fusions of ALK with other genes have also been reported. Other mutations that occur in less than 5% of NSCLC tumors include:
BRAF mutations are mutually exclusive of EGFR and KRAS mutations. Somatic mutations in MAP2K1 (also known as MEK) have been identified in 1% of NSCLC. MET oncogene encodes hepatocyte growth factor receptor. Amplification of this gene has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.
In non-small cell lung cancer (NSCLC), the determination of stage has important therapeutic and prognostic implications. Careful initial diagnostic evaluation to define the location and to determine the extent of primary and metastatic tumor involvement is critical for the appropriate care of patients.
In general, symptoms, physical signs, laboratory findings, or perceived risk of distant metastasis lead to an evaluation for distant metastatic disease. Additional tests such as bone scans and computed tomography (CT)/magnetic resonance imaging (MRI) of the brain may be performed if initial assessments suggest metastases or if patients with stage III disease are under consideration for aggressive local and combined modality treatments.
Stage has a critical role in the selection of therapy. The stage of disease is based on a combination of clinical factors and pathological factors. The distinction between clinical stage and pathological stage should be considered when evaluating reports of survival outcome.
Procedures used to determine staging include the following:
Procedures used to obtain tissue samples include bronchoscopy, mediastinoscopy, or anterior mediastinotomy. Pathological staging of NSCLC requires the following:
Prognostic and treatment decisions are based on some of the following factors:
At diagnosis, patients with NSCLC can be divided into the following three groups that reflect both the extent of the disease and the treatment approach:
Evaluation of mediastinal lymph node metastasis
Surgical staging of the mediastinum is considered standard if accurate evaluation of the nodal status is needed to determine therapy.
Accurate staging of the mediastinal lymph nodes provides important prognostic information.
Evidence (nodal status):
CT scanning is primarily used for determining the size of the tumor. The CT scan should extend inferiorly to include the liver and adrenal glands. MRI scans of the thorax and upper abdomen do not appear to yield advantages over CT scans.
Evidence (CT scan):
18F-FDG PET scanning
The wider availability and use of 18F-FDG PET scanning for staging has modified the approach to staging mediastinal lymph nodes and distant metastases.
Randomized trials evaluating the utility of 18F-FDG PET scanning in potentially resectable NSCLC report conflicting results in terms of the relative reduction in the number of noncurative thoracotomies.
Although the current evidence is conflicting, 18F-FDG PET scanning may improve results of early-stage lung cancer by identifying patients who have evidence of metastatic disease that is beyond the scope of surgical resection and that is not evident by standard preoperative staging procedures.
Evidence (18F-FDG PET scan):
Cost effectiveness of 18F-FDG PET scanning
Decision analyses demonstrate that 18F-FDG PET scanning may reduce the overall costs of medical care by identifying patients with falsely negative CT scans in the mediastinum or otherwise undetected sites of metastases.[9,10,11] Studies concluded that the money saved by forgoing mediastinoscopy in 18F-FDG PET-positive mediastinal lesions was not justified because of the unacceptably high number of false-positive results.[9,10,11] A randomized study found that the addition of 18F-FDG PET scanning to conventional staging was associated with significantly fewer thoracotomies. A second randomized trial evaluating the impact of 18F-FDG PET scanning on clinical management found that 18F-FDG PET scanning provided additional information regarding appropriate stage but did not lead to significantly fewer thoracotomies.
Combination of CT imaging and 18F-FDG PET scanning
The combination of CT imaging and 18F-FDG PET scanning has greater sensitivity and specificity than CT imaging alone.
Evidence (CT/18F-FDG PET scan):
For patients with clinically operable NSCLC, the recommendation is for a biopsy of mediastinal lymph nodes that were found to be larger than 1 cm in shortest transverse axis on chest CT scan or were found to be positive on 18F-FDG PET scan. Negative 18F-FDG PET scanning does not preclude biopsy of radiographically enlarged mediastinal lymph nodes. Mediastinoscopy is necessary for the detection of cancer in mediastinal lymph nodes when the results of the CT scan and 18F-FDG PET scan do not corroborate each other.
Evaluation of brain metastasis
Patients at risk for brain metastases may be staged with CT or MRI scans. One study randomly assigned 332 patients with potentially operable NSCLC and no neurological symptoms to brain CT or MRI imaging to detect occult brain metastasis before lung surgery. MRI showed a trend towards a higher preoperative detection rate than CT scan (P = .069), with an overall detection rate of approximately 7% from pretreatment to 12 months after surgery. Patients with stage I or stage II disease had a detection rate of 4% (i.e., eight detections out of 200 patients); however, individuals with stage III disease had a detection rate of 11.4% (i.e., 15 detections out of 132 patients). The mean maximal diameter of the brain metastases was significantly smaller in the MRI group. Whether the improved detection rate of MRI translates into improved outcome remains unknown. Not all patients are able to tolerate MRI, and for these patients contrast-enhanced CT scan is a reasonable substitute.
Evaluation of distant metastasis other than the brain
Numerous nonrandomized, prospective, and retrospective studies have demonstrated that 18F-FDG PET scanning seems to offer diagnostic advantages over conventional imaging in staging distant metastatic disease; however, standard 18F-FDG PET scans have limitations. 18F-FDG PET scans may not extend below the pelvis and may not detect bone metastases in the long bones of the lower extremities. Because the metabolic tracer used in 18F-FDG PET scanning accumulates in the brain and urinary tract, 18F-FDG PET scanning is not reliable for detection of metastases in these sites.
The Revised International System for Staging Lung Cancer
The Revised International System for Staging Lung Cancer, based on information from a clinical database of more than 5,000 patients, was adopted in 2010 by the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer.[18,19] These revisions provide greater prognostic specificity for patient groups; however, the correlation between stage and prognosis predates the widespread availability of PET imaging.
AJCC Stage Groupings and TNM Definitions
The AJCC has designated staging by TNM (tumor, node, metastasis) classification to define NSCLC.
In non-small cell lung cancer (NSCLC), results of standard treatment are poor except for the most localized cancers. All newly diagnosed patients with NSCLC are potential candidates for studies evaluating new forms of treatment.
Surgery is potentially the most curative therapeutic option for this disease. Postoperative chemotherapy may provide an additional benefit to patients with resected NSCLC. Radiation therapy combined with chemotherapy can produce a cure in a small number of patients and can provide palliation in most patients. Prophylactic cranial irradiation may reduce the incidence of brain metastases, but there is no evidence of a survival benefit and the effect of prophylactic cranial irradiation on quality of life is not known.[1,2] In patients with advanced-stage disease, chemotherapy or epidermal growth factor receptor (EGFR) kinase inhibitors offer modest improvements in median survival, although overall survival is poor.[3,4]
Chemotherapy has produced short-term improvement in disease-related symptoms in patients with advanced NSCLC. Several clinical trials have attempted to assess the impact of chemotherapy on tumor-related symptoms and quality of life. In total, these studies suggest that tumor-related symptoms may be controlled by chemotherapy without adversely affecting overall quality of life;[5,6] however, the impact of chemotherapy on quality of life requires more study. In general, medically fit elderly patients with good performance status obtain the same benefits from treatment as younger patients.
The identification of gene mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease. In particular, genetic abnormalities in EGFR, MAPK, and PI3K signaling pathways in subsets of NSCLC may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors. EGFR mutations strongly predict the improved response rate and progression-free survival of inhibitors of EGFR. Fusions of ALK with EML4 and other genes form translocation products that occur in ranges from 3% to 7% in unselected NSCLC and are responsive to pharmacological inhibition of ALK by agents such as crizotinib. The MET oncogene encodes hepatocyte growth factor receptor. Amplification of this gene has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.
The standard treatment options for each stage of NSCLC are presented in Table 7.
In addition to the standard treatment options presented in Table 7, treatment options under clinical evaluation include the following:
Several small series have reported that reduction in fluorine F 18-fludeoxyglucose positron emission tomography (18F-FDG PET) after chemotherapy, radiation therapy, or chemoradiation therapy correlates with pathological complete response and favorable prognosis.[8,9,10,11,12,13,14,15] Studies have used different timing of assessments, 18F-FDG PET parameters, and cutpoints to define 18F-FDG PET response. Reduction in maximum standardized uptake value (SUV) of higher than 80% predicted for complete pathological response with a sensitivity of 90%, specificity of 100%, and accuracy of 96%. Median survival after resection was longer for patients with tumor SUV values of lower than 4 (56 months vs. 19 months). Patients with complete metabolic response following radiation therapy were reported to have median survivals of 31 months versus 11 months.
18F-FDG PET may be more sensitive and specific than computed tomography (CT) scan in assessing response to induction therapy. Optimal timing of imaging remains to be defined; however, one study suggested that greater sensitivity and specificity of 18F-FDG PET is achieved if repeat imaging is delayed until 30 days after radiation therapy.
There is no clear role for routine posttreatment PET-CT scans.[Level of evidence: 3iiA]
Evidence (surveillance imaging after radiation therapy with or without chemotherapy):
Current Clinical Trials
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
In occult lung cancer, a diagnostic evaluation often includes chest x-ray and selective bronchoscopy with close follow-up (e.g., computed tomography scan), when needed, to define the site and nature of the primary tumor; tumors discovered in this fashion are generally early stage and curable by surgery.
After discovery of the primary tumor, treatment involves establishing the stage of the tumor. Therapy is identical to that recommended for other non-small cell lung cancer (NSCLC) patients with similar-stage disease.
Standard Treatment Options for Occult NSCLC
Standard treatment options for occult NSCLC include the following:
Stage 0 non-small cell lung cancer (NSCLC) frequently progresses to invasive cancer.[1,2,3] Patients may be offered surveillance bronchoscopies and, if lesions are detected, potentially curative therapies.
Standard Treatment Options for Stage 0 NSCLC
Standard treatment options for stage 0 NSCLC include the following:
Segmentectomy or wedge resection are used to preserve maximum normal pulmonary tissue because patients with stage 0 NSCLC are at a high risk for second lung cancers. Because these tumors are by definition noninvasive and incapable of metastasizing, they should be curable with surgical resection; however, such lesions, when identified, are often centrally located and may require a lobectomy.
Patients with central lesions may be candidates for curative endobronchial therapy. Endobronchial therapies that preserve lung function include photodynamic therapy, electrocautery, cryotherapy, and Nd-YAG laser therapy.[3,4,5,6]
Evidence (endobronchial therapies):
Efficacy of these treatment modalities in the management of patients with early NSCLC remains to be proven in definitive randomized controlled trials.
There is a high incidence of second primary cancers developing.[1,2]
Standard Treatment Options for Stages IA and IB NSCLC
Standard treatment options for stages IA non-small cell lung cancer (NSCLC) and IB NSCLC include the following:
Chemotherapy and radiation therapy have not been shown to improve outcomes in stage I NSCLC that has been completely resected.
Surgery is the treatment of choice for patients with stage I NSCLC. A lobectomy or segmental, wedge, or sleeve resection may be performed as appropriate. Patients with impaired pulmonary function are candidates for segmental or wedge resection of the primary tumor. Careful preoperative assessment of the patient's overall medical condition, especially the patient's pulmonary reserve, is critical in considering the benefits of surgery. The immediate postoperative mortality rate is age related, but a 3% to 5% mortality rate with lobectomy can be expected.
Current evidence suggests that lung cancer resection combined with CMLND is not associated with improvement in survival compared with lung cancer resection combined with systematic sampling of mediastinal lymph nodes in patients with stage I, II, or IIIA NSCLC.[Level of evidence: 1iiA]
Limitations of evidence (surgery):
Conclusions about the efficacy of surgery for patients with local and locoregional NSCLC are limited by the small number of participants studied to date and the potential methodological weaknesses of the trials.
Many patients treated surgically subsequently develop regional or distant metastases. Such patients are candidates for entry into clinical trials evaluating postoperative treatment with chemotherapy or radiation therapy following surgery. At present, neither chemotherapy nor radiation therapy has been found to improve the outcome of patients with stage I NSCLC that has been completely resected.
Adjuvant radiation therapy
The value of postoperative (adjuvant) radiation therapy (PORT) has been evaluated and has not been found to improve the outcome of patients with completely resected stage I NSCLC.
Evidence (adjuvant radiation therapy):
Further analysis is needed to determine whether these outcomes can potentially be modified with technical improvements, better definitions of target volumes, and limitation of cardiac volume in the radiation portals.
The value of intraoperative (adjuvant) brachytherapy applied to the suture line has been evaluated in patients undergoing sublobar resections for stage I NSCLC to improve local control; it has not been found to improve outcomes.
Evidence (adjuvant brachytherapy):
Based on a meta-analysis, postoperative chemotherapy is not recommended outside of a clinical trial for patients with completely resected stage I NSCLC.[11,12][Level of evidence: 1iiA]
Evidence (adjuvant chemotherapy for stage I NSCLC):
Although there is sufficient evidence that postoperative chemotherapy is effective in patients with stage II or stage IIIA NSCLC, its usefulness in patients with stage IB NSCLC is less clear.
Evidence (adjuvant chemotherapy for stage IB NSCLC):
Given the magnitude of observed survival differences, CALGB-9633 may have been underpowered to detect small but clinically meaningful improvements in survival. In addition, the use of a carboplatin versus a cisplatin combination might have affected the results. At present, there is no reliable evidence that postoperative chemotherapy improves survival of patients with stage IB NSCLC.[Level of evidence: 1iiA]
Patients with potentially resectable tumors with medical contraindications to surgery or those with inoperable stage I disease and with sufficient pulmonary reserve may be candidates for radiation therapy with curative intent.
Conventional radiation therapy
Historically, conventional primary radiation therapy consisted of approximately 60 Gy to 70 Gy delivered with megavoltage equipment to the midplane of the known tumor volume using conventional fractionation (1.8–2.0 Gy per day).
In the largest retrospective conventional radiation therapy series, patients with inoperable disease treated with definitive radiation therapy achieved 5-year survival rates of 10% to 30%.[21,22,23] Several series demonstrated that patients with T1, N0 tumors had better outcomes, and 5-year survival rates of 30% to 60% were found in this subgroup.[21,22,24] However, local-only failure occurs in as many as 50% of patients treated with conventional radiation therapy to doses in the range of 60 Gy to 65 Gy.[25,26]
Evidence (conventional radiation therapy):
A substantial number of patients are ineligible for standard surgical resection because of comorbid conditions that are associated with unacceptably high perioperative risk. Observation and radiation therapy may be considered for these patients.[27,28,29] Nonrandomized observational studies comparing treatment outcomes associated with resection, radiation therapy, and observation have demonstrated shorter survival times and higher mortality for patients treated with observation only.[27,30]
Improvements in radiation techniques include planning techniques to account for tumor motion, more conformal planning techniques (e.g., 3-D conformal radiation therapy and intensity-modulated radiation therapy), and image guidance during treatment. Modern approaches to delivery of EBRT include hypofractionated radiation therapy and stereotactic body radiation therapy (SBRT).However, there are limited reliable data from comparative trials to determine which approaches yield superior outcomes.[28,29]
Hypofractionated radiation therapy
Hypofractionated radiation therapy involves the delivery of a slightly higher dose of radiation therapy per day (e.g., 2.4–4.0 Gy) over a shorter period of time compared with conventionally fractionated radiation therapy. Multiple prospective phase I/II trials have demonstrated that hypofractionated radiation therapy to a dose of 60 Gy to 70 Gy delivered over 3 to 4 weeks with 2.4 Gy to 4.0 Gy per day resulted in a low incidence of moderate to severe toxicity, 2-year OS of 50% to 60%, and 2-year tumor local control of 80% to 90%.[31,32,33][Level of evidence: 3iiiA]
Stereotactic body radiation therapy (SBRT)
SBRT involves the delivery of highly conformal, high-dose radiation therapy over an extremely hypofractionated course (e.g., one to five treatments) delivered over 1 to 2 weeks. Commonly used regimens include 18 Gy × 3, 12 Gy to 12.5 Gy × 4, and 10 Gy to 12 Gy × 5, and deliver a substantially higher biologically effective dose compared with historic conventional radiation therapy regimens.
Multiple prospective phase I/II trials and institutional series have demonstrated that SBRT results in a low incidence of pulmonary toxicity (<10% risk of symptomatic radiation pneumonitis), 2-year OS of 50% to 60%, and 2-year tumor control of 90% to 95%.[34,35,36,37,38,39,40][Level of evidence: 3iiiA]
Randomized trials of conventional radiation therapy versus SBRT (NCT01014130), and hypofractionated radiation therapy versus SBRT (LUSTRE [NCT01968941]) are ongoing to determine the optimal radiation therapy regimen, but stereotactic body radiation therapy has been widely adopted for patients with medically inoperable stage I NSCLC.
Treatment Options Under Clinical Evaluation
Treatment options under clinical evaluation include the following:
Standard Treatment Options for Stages IIA and IIB NSCLC
Standard treatment options for stages IIA non-small cell lung cancer (NSCLC) and IIB NSCLC include the following:
Adjuvant radiation therapy has not been shown to improve outcomes in patients with stage II NSCLC.
Surgery is the treatment of choice for patients with stage II NSCLC. A lobectomy, pneumonectomy, or segmental resection, wedge resection, or sleeve resection may be performed as appropriate. Careful preoperative assessment of the patient's overall medical condition, especially the patient's pulmonary reserve, is critical in considering the benefits of surgery. Despite the immediate and age-related postoperative mortality rate, a 5% to 8% mortality rate with pneumonectomy or a 3% to 5% mortality rate with lobectomy can be expected.
Current evidence suggests that lung cancer resection combined with CMLND is not associated with improvement in survival compared with lung cancer resection combined with systematic sampling of mediastinal lymph nodes in patients with stage I, II, or IIIA NSCLC.[Level of evidence: 1iiA]
Conclusions about the efficacy of surgery for patients with local and locoregional NSCLC are limited by the small number of participants studied to date and potential methodological weaknesses of the trials.
The preponderance of evidence indicates that postoperative cisplatin combination chemotherapy provides a significant survival advantage to patients with resected stage II NSCLC. Preoperative chemotherapy may also provide survival benefit. The optimal sequence of surgery and chemotherapy and the benefits and risks of postoperative radiation therapy in patients with resectable NSCLC remain to be determined.
After surgery, many patients develop regional or distant metastases. Several randomized, controlled trials and meta-analyses have evaluated the use of postoperative chemotherapy in patients with stage I, II, and IIIA NSCLC.[5,6,7,8,9,10,11]
Evidence (adjuvant chemotherapy):
Based on these data, patients with completely resected stage II lung cancer may benefit from postoperative cisplatin-based chemotherapy.[Level of evidence: 1iiA]
The role of chemotherapy before surgery was tested in clinical trials. The proposed benefits of preoperative chemotherapy include the following:
Preoperative chemotherapy may, however, delay potentially curative surgery.
Evidence (neoadjuvant chemotherapy):
The value of postoperative (adjuvant) radiation therapy (PORT) has been evaluated.
Further analysis is needed to determine whether these outcomes can potentially be modified with technical improvements, better definitions of target volumes, and limitation of cardiac volume in the radiation portals.
Patients with potentially operable tumors with medical contraindications to surgery or those with inoperable stage II disease and with sufficient pulmonary reserve are candidates for radiation therapy with curative intent. Primary radiation therapy often consists of approximately 60 Gy delivered with megavoltage equipment to the midplane of the volume of the known tumor using conventional fractionation. A boost to the cone down field of the primary tumor is frequently used to enhance local control. Careful treatment planning with precise definition of target volume and avoidance of critical normal structures, to the extent possible, is needed for optimal results; this requires the use of a simulator.
Among patients with excellent PS, a 3-year survival rate of 20% may be expected if a course of radiation therapy with curative intent can be completed.
Evidence (radiation therapy):
Patients with stage IIIA non-small cell lung cancer (NSCLC) are a heterogenous group. Patients may have metastases to ipsilateral mediastinal nodes, potentially resectable T3 tumors invading the chest wall, or mediastinal involvement with metastases to peribronchial or hilar lymph nodes (N1). Presentations of disease range from resectable tumors with microscopic metastases to lymph nodes to unresectable, bulky disease involving multiple nodal stations.
Patients with clinical stage IIIA N2 disease have a 5-year overall survival (OS) rate of 10% to 15%; however, patients with bulky mediastinal involvement (i.e., visible on chest radiography) have a 5-year survival rate of 2% to 5%. Depending on clinical circumstances, the principal forms of treatment that are considered for patients with stage IIIA NSCLC are radiation therapy, chemotherapy, surgery, and combinations of these modalities.
Treatment options vary according to the location of the tumor and whether it is resectable.
Standard Treatment Options for Resected/Resectable Stage IIIA N2 NSCLC
Despite careful preoperative staging, some patients will be found to have metastases to mediastinal N2 lymph nodes at thoracotomy.
Standard treatment options for resected/resectable disease include the following:
The preponderance of evidence indicates that postoperative cisplatin combination chemotherapy provides a significant survival advantage to patients with resected NSCLC with occult N2 disease discovered at surgery. The optimal sequence of surgery and chemotherapy and the benefits and risks of postoperative radiation therapy in patients with resectable NSCLC are yet to be determined.
If complete resection of tumor and lymph nodes is possible, such patients may benefit from surgery followed by postoperative chemotherapy. Current evidence suggests that lung cancer resection combined with complete ipsilateral mediastinal lymph node dissection (CMLND) is not associated with improvement in survival compared with lung cancer resection combined with systematic sampling of mediastinal lymph nodes in patients with stage I, II, or IIIA NSCLC.[Level of evidence: 1iiA]
The addition of surgery to chemoradiation therapy for patients with stage IIIA NSCLC did not result in improved OS in a phase III trial but did improve progression-free survival (PFS) and local control.[Level of evidence: 1iiDiii]
Conclusions about the efficacy of surgery for patients with local and locoregional NSCLC are limited by the small number of participants studied to date and by the potential methodological weaknesses of the trials.
The role of chemotherapy before surgery in patients with stage III N2 NSCLC has been extensively tested in clinical trials. The proposed benefits of preoperative (neoadjuvant) chemotherapy include the following:
Neoadjuvant chemoradiation therapy
Administering concurrent neoadjuvant chemotherapy and radiation therapy before surgery may intensify treatment and increase the likelihood of downstaging the tumor burden. Commonly utilized regimens that have been tested in the phase II setting include cisplatin/etoposide (EP5050) and weekly carboplatin/paclitaxel.[8,9] In a randomized trial of neoadjuvant chemoradiation therapy and surgery versus concurrent chemoradiation therapy alone, there was no difference in OS, but surgery improved PFS and local control.[Level of evidence: 1iiDiii]
Evidence (neoadjuvant chemoradiation therapy):
A direct comparison of neoadjuvant chemotherapy versus neoadjuvant chemoradiation therapy using modern treatment regimens has not been performed to date; the optimal neoadjuvant approach remains unclear.
Patients with completely resected stage IIIA NSCLC may benefit from postoperative cisplatin-based chemotherapy.[Level of evidence: 1iiA]
Evidence from randomized controlled clinical trials indicates that when stage IIIA NSCLC is encountered unexpectedly at surgery, chemotherapy given after complete resection improves survival.
Several randomized, controlled trials and meta-analyses have evaluated the use of postoperative chemotherapy in patients with stages I, II, and IIIA NSCLC.[10,11,12,13,14,15,16]
Adjuvant chemoradiation therapy
Combination chemotherapy and radiation therapy administered before or following surgery should be viewed as investigational and requiring evaluation in future clinical trials.
Evidence (adjuvant chemoradiation therapy):
The value of PORT has been assessed. Although some studies suggest that PORT can improve local control for node-positive patients whose tumors were resected, it remains controversial whether it can improve survival. The optimal dose of thoracic PORT is not known at this time. The majority of studies cited used doses ranging from 30 Gy to 60 Gy, typically provided in 2 Gy to 2.5 Gy fractions.
As referred to in the National Cancer Institute of Canada (NCIC) Clinical Trials Group JBR.10 study (NCT00002583), PORT may be considered in selected patients to reduce the risk of local recurrence, if any of the following are present:
Evidence from one large meta-analysis, subset analyses of randomized trials, and one large population study suggest that PORT may reduce local recurrence. Results from these studies on the effect of PORT on OS are conflicting.
There is benefit of PORT in stage IIIA N2 disease, and the role of PORT in early stages of NSCLC should be clarified in ongoing phase III trials. Further analysis is needed to determine whether these outcomes can be modified with technical improvements, better definitions of target volumes, and limitation of cardiac volume in the radiation portals.
Standard Treatment Options for Unresectable Stage IIIA N2 NSCLC
Standard treatment options for patients with unresectable NSCLC include the following:
For treatment of locally advanced unresectable tumor
Radiation therapy alone, administered sequentially with chemotherapy and concurrently with chemotherapy, may provide benefit to patients with locally advanced unresectable stage III NSCLC.
Radiation therapy with traditional dose and fractionation schedules (1.8–2.0 Gy per fraction per day to 60–70 Gy in 6–7 weeks) results in reproducible long-term survival benefit in 5% to 10% of patients and significant palliation of symptoms.
Evidence (radiation therapy for locally advanced unresectable tumor):
Although patients with unresectable stage IIIA disease may benefit from radiation therapy, long-term outcomes have generally been poor because of local and systemic relapse.
For patients requiring palliative treatment
Radiation therapy may be effective in palliating symptomatic local involvement with NSCLC, such as the following:
In some cases, endobronchial laser therapy and/or brachytherapy has been used to alleviate proximal obstructing lesions.
Evidence (radiation therapy for palliative treatment):
The addition of sequential and concurrent chemotherapy to radiation therapy has been evaluated in prospective randomized trials and meta-analyses. Overall, concurrent treatment may provide the greatest benefit in survival with an increase in toxic effects.
Concomitant platinum-based radiation chemotherapy may improve survival of patients with locally advanced NSCLC. However, the available data are insufficient to accurately define the size of such a potential treatment benefit and the optimal schedule of chemotherapy.
Evidence (chemoradiation therapy):
Concurrent versus sequential chemoradiation therapy
The results from two randomized trials (including RTOG-9410 [NCT01134861]) and a meta-analysis indicate that concurrent chemotherapy and radiation therapy may provide greater survival benefit, albeit with more toxic effects, than sequential chemotherapy and radiation therapy.[36,37,38][Level of evidence: 1iiA]
Evidence (concurrent vs. sequential chemoradiation therapy):
Radiation therapy dose escalation for concurrent chemoradiation
With improvement in radiation therapy–delivery technology in the 1990s, including tumor-motion management and image guidance, phase I/II trials demonstrated the feasibility of dose-escalation radiation therapy to 74 Gy with concurrent chemotherapy.[40,41,42] However, a phase III trial of a conventional dose of 60 Gy versus dose escalation to 74 Gy with concurrent weekly carboplatin/paclitaxel did not demonstrate improved local control or PFS, and OS was worse with dose escalation (HR, 1.38 [1.09–1.76]; P = .004). There was a nonsignificant increase in grade 5 events with dose escalation (10% vs. 2%) and higher incidence of grade 3 esophagitis (21% vs. 7%; P =.0003). Thus, there is no clear benefit in radiation dose escalation beyond 60 Gy for stage III NSCLC.[Level of evidence: 1iiA]
Choice of systemic therapy for concurrent chemoradiation
Evidence (systemic therapy for concurrent chemoradiation):
The primary objective was OS. The study was designed as a superiority trial with 80% power to detect an OS HR of 0.74 with a type 1 error of .05. This study randomly assigned 598 patients (arm A, 301; arm B, 297) and treated 555 patients (arm A, 283; arm B, 272).
Additional systemic therapy before or after concurrent chemotherapy and radiation therapy
The addition of induction chemotherapy before concurrent chemotherapy and radiation therapy has not been shown to improve survival.[Level of evidence: 1iiA]
Durvalumab is a selective human IgG1 monoclonal antibody that blocks programmed death ligand 1 (PD-L1) binding to programmed death 1 (PD-1) and CD80, allowing T cells to recognize and kill tumor cells.
Other systemic consolidation therapies
Randomized trials of other consolidation systemic therapies, including docetaxel, gefitinib, and tecemotide (MUC1 antigen-specific immunotherapy)  have not shown an improvement in OS.[Level of evidence: 1iiA]
Standard Treatment Options for Superior Sulcus Tumors (T3, N0 or N1, M0)
Standard treatment options for superior sulcus tumors include the following:
NSCLC of the superior sulcus, frequently termed Pancoast tumors, occurs in less than 5% of patients.[50,51] Superior sulcus tumors usually arise from the apex of the lung and are challenging to treat because of their proximity to structures at the thoracic inlet. At this location, tumors may invade the parietal pleura, chest wall, brachial plexus, subclavian vessels, stellate ganglion, and adjacent vertebral bodies. However, Pancoast tumors are amenable to curative treatment, especially in patients with T3, N0 disease.
Adverse prognostic factors include the presence of mediastinal nodal metastases (N2 disease), spine or subclavian-vessel involvement (T4 disease), and limited resection (R1 or R2).
Radiation therapy alone
While radiation therapy is an integral part of the treatment of Pancoast tumors, variations in dose, treatment technique, and staging that were used in various published series make it difficult to determine its effectiveness.[50,51]
Small, retrospective series of radiation therapy in patients who were only clinically staged have reported 5-year survival rates of 0% to 40%, depending on T stage, total radiation dose, and other prognostic factors. Induction radiation therapy and en-bloc resection was shown to be potentially curative.
Chemoradiation therapy followed by surgery
With improvement in radiation therapy–delivery technology in the 1990s, including tumor-motion management and image guidance, phase I/II trials demonstrated the feasibility of dose-escalation radiation therapy to 74 Gy with concurrent chemotherapy.[40,41,42] However, a phase III trial of a conventional dose of 60 Gy versus dose escalation to 74 Gy with concurrent weekly carboplatin/paclitaxel did not demonstrate improved local control or PFS, and OS was worse with dose escalation (HR, 1.38 [1.09–1.76]; P = .004). There was a nonsignificant increase in grade 5 events with dose escalation (10% vs. 2%) and higher incidence of grade 3 esophagitis (21% vs. 7%; P = .0003). Thus, there is no clear benefit in radiation dose escalation beyond 60 Gy for stage III NSCLC.[Level of evidence: 1iiA]
The addition of induction chemotherapy before concurrent