Retrospective analysis of risk factors for left-sided vs right-sided colon cancer in a southern Chinese Han population

Figure 1 Study flowchart for the comparative analysis of left-sided colorectal cancer and right-sided colorectal cancer. The study began with the collection of data from 2580 colorectal cancer (CRC) patients, of whom 2009 met the inclusion or exclusion criteria and were included in the analysis [1132 left-sided CRC (L-CRC), 877 right-sided CRC (R-CRC) and 600 control]. Clinical data, including demographics, laboratory tests [triglyceride (TG), low-density lipoprotein (LDL)], medical and family history, and lifestyle factors (smoking, alcohol), were collected. Logistic regression analysis was conducted to identify major factors associated with L-CRC vs R-CRC, using age, TG, LDL, past history, family history, smoking, alcohol, and tumor stage as input variables. The analysis included both univariable and multivariable models to estimate adjusted ORs and 95%CIs. Comparative analysis was performed using t-tests for continuous variables (age, TG, LDL), χ² tests for binary variables (past medical history, family history, smoking, alcohol), and Mann-Whitney U tests for ordinal variables (tumor stage). L-CRC: Left-sided colorectal cancer; R-CRC: Right-sided colorectal cancer; BMI: Body mass index.