Survival comparison of stage IIA rectal cancer with or without neoadjuvant therapy: a SEER database analysis with propensity score matching.

Background: Patients with stage IIA rectal cancer have a higher survival rate but side effects from chemoradiotherapy; thus, whether neoadjuvant therapy should be performed for stage IIA rectal cancer is controversial. This study aimed to compare the survival outcomes of patients with stage IIA rectal cancer with or without neoadjuvant chemoradiotherapy.

Methods: Patients with stage IIA rectal cancer between 2010 and 2015 were included through the Surveillance, Epidemiology, and End Results database. Propensity score matching was used to reduce the impact of confounding factors. Survival curves were plotted using the Kaplan-Meier method, and survival differences were assessed using the log-rank test.

Results: There were no significant differences in overall survival and cancer-specific survival between the neoadjuvant chemoradiotherapy and surgery groups (P=0.973 and 0.983). Compared with the surgery group, the neoadjuvant chemoradiotherapy + surgery + chemotherapy group had a better overall survival (P=0.007). Subgroup analysis showed that the neoadjuvant chemoradiotherapy + surgery + chemotherapy group had better overall survival compared to the surgery group in the subgroup containing preoperative high-risk factors (P=0.003) but not in the low-risk subgroup (P=0.685).

Conclusions: There is no evidence that neoadjuvant chemoradiotherapy + surgery can improve overall survival and cancer-specific survival compared to surgery alone in patients with stage IIA rectal cancer. Neoadjuvant chemoradiotherapy + surgery + chemotherapy can improve overall survival compared to surgery alone, but only in patients with preoperative high-risk factors. We suggest that patients with no preoperative high-risk factors may be considered for surgery alone, neoadjuvant chemoradiotherapy + surgery + chemotherapy is recommended for patients with preoperative risk factors.