Local Nonsurgical Therapies for Stage I and Symptomatic Obstructive Non–Small-Cell Lung Cancer Executive Summary

Non–small-cell lung cancer (NSCLC) refers to any type of epithelial lung cancer other than small-cell lung cancer.1 The disease arises from epithelial cells of the lung, from the central bronchi to terminal alveoli. The histological type correlates with site of origin, reflecting the variation in respiratory tract epithelium by location. The most common types of NSCLC are adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Several other types occur less frequently; all can occur in unusual histological variants. Squamous cell carcinoma typically originates near a central bronchus. Adenocarcinoma and adenocarcinoma in situ (formerly called bronchioalveolar carcinoma) usually arise in peripheral lung tissue. Adenocarcinomas are frequently associated with cigarette smoke but may also occur in patients who have never smoked.