Adverse Histological Features Alone Was Not Sufficient for Decision of Adjuvant Chemotherapy in T3N0M0 colonic cancer: A Propensity Score Matching Study Based on Population Analysis

Abstract

\n Purpose: Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Approximately 25% of patients with AJCC stage II suffered recurrence after radical surgery, but the role of adjuvant chemotherapy in Stage II CRC is controversial. We aimed to evaluate the benefit from chemotherapy for T3N0M0 patients with adverse histological features. Methods: An analysis of the Surveillance, Epidemiology, and End Results (SEER) 18 databases was performed to identify patients underwent radical resection 20-80 years old with colonic carcinoma diagnosed during year 2004 to 2012. Poorly differentiated, undifferentiated, mucinous adenocarcinoma and signet ring cell carcinoma (SRCC) were defined as adverse histological features, and well or moderately differentiated adenocarcinoma as good histological features. Multivariate analyses were used to adjust the effects of other covariates. The survival benefit of adjuvant chemotherapy was demonstrated in the propensity score matching cohort. Results: The adjuvant chemotherapy brought no survival benefit (good histological features HR, 1.076; 95% CI, 0.957-1.211; P=0.220; adverse histological features HR, 0.995; 95% CI, 0.777-1.274; P=0.967); Neither mucinous adenocarcinoma nor signet ring cell carcinoma brought a significance on survival (mucinous adenocarcinoma HR, 0.699; 95% CI, 0.488-1.002; P=0.051; signet ring cell carcinoma HR, 0.750; 95% CI, 0.386-1.459; P=0.397) compared to adenocarcinoma. Left-side colon was associated with a poorer survival in good histological features group (HR, 1.136; 95% CI, 1.034-1.248; P=0.008). Conclusions: The adverse histological features don’t influence on survival for patients with T3N0M0 staging, and adjuvant chemotherapy is invalid to improve the survival for these patients, indicating adverse histological features alone was not sufficient for decision of adjuvant chemotherapy in this situation rather than the recommendation of the guidelines.