Risk factors for recurrence in stage I colorectal cancer after curative resection: a systematic review and meta-analysis

Purpose Patients with stage I colorectal cancer (CRC) rarely experience recurrence after curative resection. Therefore, the risk factors for stage I CRC recurrence are yet to be established. We aimed to identify risk factors for stage I CRC recurrence. Methods MEDLINE, Embase, and Cochrane Library were searched for articles published between 1990 and 2022. The pooled proportions and hazard ratios (HRs) were calculated. Fixed- or random-effect models were considered based on heterogeneity, using Cochran's Q-statistic and the I-2-test. Results Nine studies involving 19,440 patients were included. Nine analyzed risk factors were identified. T2 stage (pooled HR, 2.070; 95% confidence interval [CI], 1.758-2.438; P < 0.001; I-2=0.0%), lymphovascular invasion (HR, 1.685; 95% CI, 1.420-1.999; P < 0.001; I-2 = 0.0%), venous invasion (HR, 1.794; 95% CI, 1.515-2.125; P < 0.001; I-2 = 0.0%), CEA level (HR, 1.472; 95% CI, 1.093-1.983; P = 0.011; I-2 = 1.8%) and rectal cancer (HR, 2.981; 95% CI, 2.378-3.735; P < 0.001; I-2 = 0.0%) were risk factors for the recurrence. However, the risk of recurrence in right-sided colon cancer was lower than in left-sided colon cancer. (HR, 0.712; 95% CI, 0.537-0.944; P = 0.018; I-2 = 0.0%). No statistically significant differences were observed in the number of harvested lymph nodes, age, and sex. Conclusion T2 stage, lymphovascular invasion, venous invasion, CEA level, rectal cancer, and left-sided colon cancer were risk factors for recurrence in stage I CRC. Intensive monitoring and surveillance are warranted for patients with high-risk features of recurrence.