Association between cigarette smoking and colorectal cancer sidedness: A multi-center big-data platform-based analysis

Abstract Background Sidedness (right/left) of colorectal cancer (CRC) is essential for treatment. Whether carcinogenesis of tobacco varies by sidedness remains unclear. The present study aims to evaluate the sidedness tendency of cigarette smoking and to explore its impact on prognosis. Methods In the multi-center retrospective study, data on 46 166 Chinese CRC patients were extracted from a big-data platform. Logistic regression analyses were performed to evaluate qualitative and quantitative associations between smoking and tumor sidedness. Survival analyses were conducted in metastatic CRC. Results History of smoking was associated with left-sided CRC (LSCRC; Adjusted odds ratio, 1.25; 95% CI, 1.16 − 1.34; P