[A Case of Locally Advanced Rectal Cancer Curatively Resected Following Chemoradiotherapy]

A man in his 70s was referred to our hospital with anorexia, weight loss, and constipation. After examination by computed tomography (CT), magnetic resonance imaging (MRI), and colonoscopy, he was diagnosed as having a locally advanced rectal cancer with abscess formation. Because CT and MRI indicated that the tumor had invaded the seminal vesicle, prostate, and sacrum, we diagnosed it as an unresectable tumor. We treated the abscesses around the tumor by sigmoid colostomy with administration of antibiotics. After control of the infection, the patient received systemic chemotherapy with capecitabine/oxaliplatin (XELOX) plus bevacizumab (BV). After the 5th courses of XELOX plus BV, the primary tumor showed a tendency to shrink, but invasion to the neighboring organs was still seen. Therefore, we treated him with chemoradiotherapy (CRT) using S-1. After completion of CRT with no significant adverse effects, the tumor invasion to the neighboring organs disappeared, and we performed a low anterior resection 9 weeks later. Pathological findings revealed that the tumor had shrunk remarkably and it was resected curatively, although a few tumor cells remained in the subserosal layer of the ulcerative scar caused by the CRT. His postoperative course was uneventful, and he underwent adjuvant chemotherapy with S-1 for 3 months after discharge. To date, no disease recurrence has been detected. We report a case of locally advanced rectal cancer, which was curatively resected following chemoradiotherapy, along with a short literature review.