Case Report of a Clinically Complete Response in a Rectal Cancer Patient after Chemoradiotherapy with a 2-year Watch and Wait Approach

抄録

Background: A non-operative treatment strategy including chemoradiation (CRT) for rectal cancer, that is to say, watch and wait, is not currently recommended in Japan. However, some rectal cancer patients show a pathologically complete response after CRT. Watch and wait has been gradually applied in the U.S. and Western countries.

Case presentation: This case report describes a case report of a clinically complete response in a rectal cancer patient after CRT with a 2-year watch and wait approach. A 40-year-old woman suffered from cancer of the lower rectum without metastasis. Preoperative neoadjuvant CRT was thought to be indicated. The total dose of preoperative radiotherapy was 50.4 Gy, which was given in a fractionated manner over a long time period (1.8 Gy×28 Fr over 6 weeks). She took tegafur-uracil (300-500mg/day) and leucovorin (75mg/day) concurrently with radiotherapy. Two months after the end of CRT, colonoscopy showed a remarkable reduction of the tumor. Although we explained to the patient the content of the surgical therapy with lymph node dissection and the possibility of stoma creation, she refused to undergo the surgery. Therefore, we planned to perform a follow-up including measurement of tumor markers, colonoscopy, and CT. She has kept a clinically complete response for two years since the end of CRT.

Conclusions: The present case showed the possibility that a watch and wait strategy might be applicable to some rectal cancer cases.