Impact of type 2 diabetes mellitus on short-term and long-term outcomes of stage iv colorectal cancer patients after primary surgery: a propensity score matching analysis

Purpose This study aims to investigate the influence of type 2 diabetes mellitus (T2DM) on stage IV colorectal cancer (CRC) patients performed primary surgery in terms of short-term and long-term outcomes. Methods Patients diagnosed with stage IV CRC and received primary CRC surgery at a single clinical center from Jan, 2013 to Jan, 2020 were included in this study. Baseline characteristics, short-term and long-term outcomes were compared between the T2DM group and the Non-T2DM group. Univariate and multivariate analysis were used to find risk factors for overall survival (OS). Propensity score matching (PSM) using a 1:1 ratio was used to minimize selective bias between the two groups. Statistical analysis was performed using SPSS (version 22.0) software. Results A total of 302 eligible patients were enrolled, and there were 54 (17.9%) patients with T2DM, and 248 (82.1%) patients without T2DM. The T2DM group had more older patients (P < 0.01), higher body mass index (BMI) (P < 0.01), and a higher proportion of hypertension (P < 0.01) than the Non-T2DM group. After PSM, there were 48 patients in each group. There were no significant differences in short-term outcomes or OS between the two groups, either before or after PSM (P > 0.05). In multivariate analysis, older age (P < 0.01, HR = 1.032, 95% CI = 1.014-1.051) and larger tumor size (P < 0.01, HR = 1.760, 95% CI = 1.179-2.626) were independent factors for OS. Conclusion Although T2DM did not influence short-term outcomes or OS in stage IV CRC patients after primary surgery, age and tumor size might have predictive value for OS.