[Two cases of advanced low rectal cancer, preoperative chemo-radiation therapy leading to complete histological...

We report two cases of advanced low rectal cancer, with preoperative chemo-radiation therapy leading to a complete histological response. Case 1 was a 74-year-old male who was diagnosed as advanced low rectal cancer. Preoperative chemo-radiation (a total of 45 Gy radiation+oral 5'-DFUR 800 mg/day for 3 weeks) was performed. Then, 30 days after chemo-radiation, we conducted a low anterior resection with lymph node dissection. Histological examination revealed no residual cancer cells in the resected specimen. Case 2 was a 35-year-old male who was diagnosed as advanced low rectal cancer. Preoperative chemo-radiation (a total of 45 Gy radiation+5-FU 500 mg/day+CDDP 10 mg/day for 3 weeks) was performed. 28 days after chemo-radiation, we conducted an abdominoperineal resection with lymph node dissection and a partial resection of the liver. Histological examination revealed well-differentiated adenocarcinoma in the resected liver tissue, but a rectal tumor was replaced by scar tissue with no viable cells.