A Case of Locally Advanced Rectal Cancer with a Pathological Complete Response to Preoperative Chemoradiotherapy

A 61-year-old woman presented with the chief complaint of melena. She was diagnosed with rectal cancer via colonoscopy. Computed tomography (CT) revealed a rectal cancer with wall thickening, accompanied by several regional lymph node metastases with no distant metastasis. The tumor stage was cT3, cN2a, cM0 according to the TNM Classification of Malignant Tumors (7th Edition, UICC). Preoperative chemoradiotherapy (CRT) (UFT 400 mg/day tegafur-uracil and 75 mg/day Leucovorin; 1.8 Gy in 25 fractions, total 45 Gy) was administered. Eight weeks after CRT, laparoscopy-assisted low anterior resection was performed. A pathological examination revealed that both the primary site and regional lymph nodes had no residual cancer cells, and a diagnosis of pathological complete response was made. The patient has been disease-free for 4 years since the operation. We report a case of rectal cancer that was successfully treated via preoperative CRT. This case may aid the development of a standard therapy for advanced rectal cancer.