Clinical study on risk factors related to postoperative recurrence or metastasis of rectal cancer: a retrospective cohort study.

Background: Rectal cancer is usually treated by surgery, but recurrence or metastasis seriously affect the quality of life and survival of patients. Identifying the risk factors for postoperative recurrence or metastasis of rectal cancer has important guiding value for the treatment of rectal cancer. However, the research on risk factors of postoperative recurrence or metastasis of rectal cancer has not been unified.

Methods: The data of all patients undergoing rectal cancer surgery in The Fifth People's Hospital of Shanghai, Fudan University, from 2016 to 2020 were collected and analyzed. A total of 185 patients were included for statistical analysis and were divided into a recurrence or metastasis group and a non-recurrence or metastasis group. Patients were followed up according to National Comprehensive Cancer Network (NCCN) guidelines by enhanced CT or MRI, and colonoscopy. The cut-off of the research was recurrence, metastasis, or death. Logistic regression analysis and Cox regression analysis were used to analyze the risk factors related to postoperative recurrence or metastasis of rectal cancer, and the survival curve was drawn.

Results: Multiple logistic regression analysis showed involvement of the mesorectal fascia (MRF) [OR (odds ratio) =2.9, 95% confidence interval (CI): 1.16-7.29, P=0.023], nerve and vascular invasion (OR =1.7, 95% CI: 1.08-2.59, P=0.022), intraoperative blood transfusion (OR =3.7, 95% CI: 1.45-9.40, P=0.006), and Dukes staging (OR =2.3, 95% CI: 1.26-4.35, P=0.007) were independent risk factors for postoperative recurrence or metastasis of rectal cancer. Involvement of mesenteric fascia infiltration (OR =11.5, 95% CI: 1.49-88.79, P=0.019) and Dukes stage (OR =3.0, 95% CI: 1.46-6.26, P=0.003) were independent risk factors for liver metastasis, while nerve and vascular invasion (OR =2.4, 95% CI: 1.19-5.00, P=0.015) was an independent risk factor for pulmonary metastasis.

Conclusions: Postoperative recurrence or metastasis of rectal cancer is related to many factors. These findings have clinical guiding value and significance for the follow up and prognosis of patients with rectal cancer after surgery. Large-scale prospective clinical studies are needed.