Predictive factors of pathological complete response after neoadjuvant therapy for locally advanced rectal cancer

Abstract

Objective To analyze the tumor characteristics associated with achieving pathological complete response(pCR) and tumor prognosis in the patients undergoing laparoscopic rectal cancer surgery after neoadjuvant chemoradiotherapy(nCRT). Methods A retrospective review was conducted on clinical and pathological data of locally advanced rectal cancer(LARC) patients who underwent nCRT at Renji Hospital from January 2017 to January 2024. Factors influencing the achievement of pCR were analyzed, and the patients prognosis of pCR group and non-pCR group was compared. ----Results Univariate analysis, multivariate Logistic regression analysis, and receiver operating characteristic (ROC) curve analysis showed that tumor length less than 5 cm(cutoff value 5.24 cm) and baseline carcinoembryonic antigen(CEA) less than 5 μg/L(cutoff value 5.33 μg/L) were independent predictors of achieving pCR after nCRT in LARC patients. Prognostic survival analysis showed that the 3-year overall survival(OS) rate for pCR group and non-pCR group were 92.86% and 82.46%, respectively (P=0.193), and the 3-year disease-free survival (DFS) rate were 85.71% and 70.18%, respectively (P=0.141), with no statistically significant differences between the two groups. Conclusions Tumor length and baseline CEA level are independent predictors for achieving pCR after nCRT in LARC patients. Additionally, there were no statistically significant differences in 3-year OS and DFS between pCR group and non-pCR group.