Bottom line: Among patients with lung cancer, squamous cell carcinoma is more common in smokers than in nonsmokers.
Details: Sun S, et al. Lung cancer in never smokers — a different disease. Nature Reviews Cancer. 2007;7: 778-790.
Reviews epidemiologic data from studies on lung cancer addressing nonsmokers (identified as lifetime exposure to less than 100 cigarettes). Fig. 1c compares proportion of lung cancers of histologic types adenocarcinoma and squamous cell carcinoma in smokers and nonsmokers. In 5,144 cases of lung cancer in nonsmokers, 18% are squamous cell carcinoma and 62% are adenocarcinoma. This is opposite the ratio in smokers. In 21,853 cases of lung cancer in smokers, 53% are squamous cell carcinoma and 19% are adenocarcinoma.