Construction And Validation Of A Model For The Risk Of Recurrence After Resection Of Liver Metastases From Colorectal Cancer Following Preoperative Chemotherapy

Objective Construction and validation of a nomogram that predicts the risk of postoperative recurrence in patients with colorectal cancer liver metastases who underwent hepatectomy after preoperative chemotherapy.Methods 138 patients with colorectal cancer liver metastases who underwent hepatic resection after preoperative chemotherapy at Cancer Hospital of University of Chinese Academy of Sciences(Zhejiang Cancer Hospital)from January 2009 to December 2019 were retrospectively analysed,and clinical and pathological information and follow-up of the patients were collected and collated and analysed,and patients were randomly assigned to the training and validation groups in a 7:3 ratio.Independent prognostic indicators were screened by using Cox regression models to construct the nomogram and predict the 1-year and 2-year disease recurrence risk probabilities for patients with colorectal cancer liver metastases.The predictive power of the nomogram was further assessed using consistency index(C-index)values,receiver operating characteristic curve,calibration plots and decision curves.Results A total of five independent prognostic indicators were included in the nomogram,these variables were tumour regression(HR 3.3[1.61-6.6],p<0.001),positive lymph nodes at the primary site(HR 2.3[1.19-4.6],p=0.013),number of metastases(HR 2.2[1.31-3.8],P=0.003),preoperative CEA(HR 2.0[1.03-3.8],p=0.039)and RAS gene mutations(HR 1.9[1.15-3.2],p=0.013).The consistency index(C-index)of the model in the training and internal validation groups(0.709 and 0.682,respectively),indicating better discriminatory power of our nomogram.The calibration curve shows that the curve of our model predicting 1-year diseasefree survival is close to the 45°line,which is closer to the actual observation.The decision curve analysis also reflects the significant improvement of our model in predicting the risk of postoperative recurrence in patients with liver metastases from colorectal cancer.Conclusions Our nomogram can be used to better determine the risk of postoperative recurrence in patients with colorectal cancer liver metastases who underwent hepatectomy after preoperative chemotherapy,thus enabling better differentiation of high-risk patients and guiding the selection of individualized treatment regimens.