[Curative Transanal Resection after Neoadjuvant Chemotherapy for Lower Rectal Cancer-A Case Report].

A 53-year-old woman was referred to our hospital with melena. Examinations revealed advanced rectal cancer involving the anal canal with invasion of the left-sided levator ani muscle. Neoadjuvant chemotherapy was administered to preserve anal function. A first course of capecitabine and oxaliplatin(CapeOX)plus bevacizumab was administered. CapeOX plus panitumumab was administered from the 2nd to the 8th courses after confirming the absence of RAS mutation. Endoscopy and computed tomography confirmed the disappearance of the tumor after completion of the chemotherapy. A biopsy of the scar tissue revealed no cancer cells. However, diffusion weighted-magnetic resonance imaging(MRI-DWI)revealed a suspected residual tumor. To determine the subsequent treatment, a transanal resection was performed. No carcinoma was identified in the specimen. Thus, additional surgical treatment and adjuvant chemotherapy were not administered. The patient was followed-up over 2.5 years post local resection and showed no recurrence.