A Case of Endoscopic Submucosal Dissection for Clinical T1b Rectal Cancer after Chemoradiotherapy

Abstract

A 70-year-old man who had positive occult blood results underwent colonoscopy which revealed a 0-Is+IIa lesion over 30 mm in size at the lower rectum diagnosed as cT1bN0M0 rectal cancer. Because he rejected surgical intervention and requested another treatment, we decided to administer chemoradiotherapy and adopt a “watch and wait” approach, provided clinical complete response had been achieved. Four weeks after CRT, colonoscopy showed that the tumor had shrunk to 25 mm in size and appeared to be LST-G. We offered low anterior resection with curative intent to the patient, but he adamantly refused radical surgery. Therefore, we performed ESD after a total of 8 weeks of chemoradiotherapy. The lesion was removed by piecemeal resection (3 pieces), but grossly complete resection of the tumor was performed. Pathological findings showed rectal cancer of tub1, pTis(M), ly0, v0, HMX, VM0. No recurrence was observed for 25 months after ESD. This case showed that ESD after chemoradiotherapy can be attempted in the case of T1-2 rectal cancer.