Background: Tobacco use increases the risk of developing gastric cancer. We examined the hypothesis that gastric cancer developing in patients with a history of tobacco use may be associated with increased risk of cancer-specific death after curative surgical resection.
Methods: From the Memorial Sloan-Kettering Cancer Center Gastric Cancer prospective surgical database, we collected baseline demographic data and tumor characteristics from all patients who had undergone curative resection for gastric cancer between 1995 and 2009 and who had not received pre- or postoperative chemo- or radiotherapy. A smoking history was defined as >100 cigarettes' lifetime use. The primary end point was gastric cancer disease-specific survival (DSS); secondary end points were 5-year disease-free survival (DFS) and overall survival (OS). Gastric cancer-specific hazard was modeled by Cox regression.
Results: A total of 699 eligible patients were identified with a median age of 70 years (range 25-96 years); 410 (59%) were current or previous smokers. Smoking was associated with gastroesophageal junction/cardia tumors and white non-Hispanic ethnicity. Multivariate analysis included the following variables: tumor stage, age, performance status, diabetes mellitus, gender, and tumor location. In this analysis, the hazard ratio for gastric cancer DSS in smokers was 1.43 (95% confidence interval 1.08-1.91, P=0.01). Smoking was also an independent significant risk factor for worse 5-year DFS (hazard ratio 1.46, P=0.007) and OS (hazard ratio 1.48, P=0.003). Among 516 patients for whom tobacco pack-year usage was available, both heavy (≥20 pack-years) and light (<20 pack-years) tobacco use was significantly associated with DSS, DFS, and OS.
Conclusions: Smoking history appears to be an independent risk factor for death from gastric cancer in patients who have undergone curative surgical resection.