Lung cancer is the leading cause of cancer death among both men and women in the USA. Smoking is an established cause of lung cancer although non-smokers (20-25% of cases) can also develop cancer of the lung. We have yet to develop an effective screening test, and consequently the vast majority of patients are diagnosed with advanced disease. The two major forms of lung cancer, non-small cell and small cell are different in terms of their patterns of progression and treatment strategies.
When a lung cancer is suspected because of symptoms or an incidental finding on a routine chest x-ray, a diagnostic work-up begins. Tissue is obtained so that a pathological diagnosis can be made and the extent of cancer spread can be determined. Once the pathology and extent of spread of the tumor are known, treatment options can be discussed. For non-small cell lung cancer, mediastinoscopy, a surgical procedure that allows tissue to be sampled from the lymph nodes in the chest, is important for determining which patients should proceed with a surgical approach.
For non-small cell lung cancers, surgery is considered the primary treatment modality if the tumor has not yet spread to the lymph nodes in the central chest. Chemotherapy is now the primary treatment modality for small cell lung cancer that spreads early to the bone marrow and distant sites including liver, opposite lung and brain. Radiation therapy currently plays a major role in the treatment of lung cancer: Inoperable non-small cell lung cancer, post-operatively in selected cases of non-small cell lung cancer and small cell lung cancer that is limited to the chest such that the disease can be encompassed in standard radiation fields. Radiation is also effective for treating symptoms such as bleeding, airway obstruction by tumor and pain.
At present the ideal sequence and combination of surgery, radiation and chemotherapy is not known; however, we have seen recent improvements in quality of life and tumor control through the introduction of newer chemotherapy agents and with better targeting of the tumor due to advances in radiation treatment planning technology.