Comparing neoadjuvant long-course chemoradiotherapy with short-course radiotherapy in rectal cancer

The purpose of this study was to compare short-course radiotherapy (SC) or neoadjuvant long-course chemoradiotherapy (LC) treatment for locally advanced rectal cancer patients.

Patients with a diagnosis of locally advanced rectal cancer (LARC) who had undergone neoadjuvant radiotherapy before surgery between 2013 and 2018 at the medical center in China were included in this study. All patients' MRI confirmed T2N+M0 or T3-4N0-3M0 clinical stages. Patients in the SC group received pelvic radiotherapy with a dose of 5 × 5 Gy (with or without chemotherapy at any time), followed by immediate or delayed surgery. Patients in the LC group received a dose of 50-50.4 Gy in 25-28 fractions, concomitantly with FOLFOX or capecitabine-based chemotherapy, followed by surgery 4-6 weeks later. All clinical data were retrospectively collected, and long-term follow-up was completed and recorded at the same time.

A total of 170 were eligible to participate in this study, 32 patients in the SC group, and 138 in the LC group. The median follow-up time of living patients was 39 months. The disease-free survival (DFS) and overall survival (OS) rates in the SC group and LC group at 3 years, were, 84.9% versus 72.4% (P = 0.273) and 96.2% versus 87.2% (P = 0.510), respectively. The complete pathological response (pCR) rates in the SC group and LC group were, 25% versus 18.1% (the difference was not statistically significant, P = 0.375), respectively. However, the SC group had better node(N) downstaging compared to the LC group (P = 0.011).

There were no differences observed in DFS and OS between short-course radiotherapy and long-course chemoradiation, and both can be used as treatment options for patients with locally advanced rectal cancer.