Impact of smoking on outcome of resected lung adenocarcinoma

Objective Smoking is a well-known causative factor of lung cancer and the association of smoking with adenocarcinoma is considered to be the weakest. We investigated the influence of smoking on postoperative prognosis in patients with lung adenocarcinoma. Methods One hundred and eighty-one consecutive patients of resected lung adenocarcinoma were studied retrospectively. The histologic subtype was subdivided into 2 groups: lepidic dominant histologic subtype, including adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic predominant invasive adenocarcinoma versus other subtypes. Results The 5-year survival of ever smokers was significantly unfavorable than that of never smokers. Similarly, there was also a relationship between the patients’ survival and Brinkman index (BI), with unfavorable survival found in patients with greater smoking histories. Based on a multivariable analysis, pN status and BI were significant factors affecting the postoperative prognosis of patients undergoing surgery. However, gender, serum carcinoembryonic antigen (CEA) level, lepidic dominant histologic subtype and pure/mixed ground-glass opacity (GGO) were not prognostic factors although previous reports showed prognostic significance. These factors that we failed to find the prognostic significance were significantly associated with smoking. Conclusion The smoking was significantly predictive of an unfavorable prognosis after surgery for lung adenocarcinoma. It is suggested that smoking is associated with serum CEA level, histologic subtype and GGO, resulting in unfavorable outcome.