Adjuvant chemotherapy for patients with ypT0-2N0-category after neoadjuvant chemoradiotherapy for rectal cancer

Locally advanced rectal cancer patients with ypT0-2N0 have good prognosis and may not require as many cycles of adjuvant chemotherapy as patients with a poor (ypT3-4 or N+) response. The aim of the present study was to evaluate the three-year disease-free and overall survival between patients with ypT0-2N0 rectal adenocarcinoma who received 0-3 cycles of 5-fluorouracil-based adjuvant chemotherapy and those who received >3 cycles. A total of 106 patients with locally advanced rectal cancer, classified as ypT0-2N0 after surgery at the Fudan University Shanghai Cancer Center (Shanghai, China) between 2006 and 2012, were identified. The patients were divided into two groups depending on the number of cycles of adjuvant chemotherapy: Group 1 received 0-3 cycles (n=32) and group 2 received ≥4 cycles of adjuvant chemotherapy (n=74). The three-year disease-free survival and overall survival rates were 86.8 and 93.1% for group 1 (P=0.633), and 88.5 and 96.8% for group 2 (P=0.381). No statistically significant difference was observed between the two groups, suggesting that patients with ypT0-2N0 status may not require more than three cycles of post-operative chemotherapy. Further evaluation in prospective studies is urgently recommended.