Recurrence after curative surgical resection of T1 rectal cancer: a report of two cases.

Recent advances in endoscopic diagnosis and treatment techniques have led to a marked increase in the detection and endoscopic treatment of early colorectal cancers (CRC). According to the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines, T1-CRC with a negative vertical margin, well- or moderately differentiated adenocarcinoma, no evidence of vascular or lymphatic invasion, and depth of invasion <1000 μm are considered to have a low risk of lymph node metastasis. However, T1-CRC with any of these risk factors are considered to have a high risk of lymph node metastasis. T1-CRC is considered to have a good prognosis if additional surgery is carried out. We experienced two cases of recurrence despite curative surgical resection of T1 rectal cancer.