Juefeng Wan

Radiation Oncology, Fudan University Shanghai Cancer Center

Objective:Retrospective studies showed that postoperative 5-FU-based chemotherapy did not prolong survival in ypStage I rectal cancer patients who had already received 5-FU-based neoadjuvant chemoradiotherapy. We designed our study to identify poor prognostic patients with ypT0-2N0 who may benefit from postoperative chemotherapy. Method: In this study, Surveillance, Epidemiology, and End Results Program (SEER)- registered rectal cancer patients, and patients from Fudan University Shanghai Cancer Center (FUSCC) after preoperative chemoradiation were combined to identify poor prognostic patients with ypT0-2N0. Result: The SEER data showed that less than 12 lymph nodes and mucinous/signet ring cancer were the two risk factors. The 5-year cancer specific survival (CSS) in patients with none, one or two risk factors was91.5%, 88.5% and 70.3%, respectively (P<0.001). Our cancer center data showed that less than 12 lymph nodes and mucinous/signet ring cancer were also the two risk factors. The 3-year disease free survival (DFS) in patients with none, one or two risk factors was 96.2%, 85% and 37.5%, respectively (P=0.013). Conclusion: These results suggest that patients with one or two risk factors may cannot be spared with adjuvant chemotherapy. Further evaluation in prospective studies is urgently recommended.

Key Words: rectal cancer  good response  SEER