[A Case of Descending Colon Cancer with Local Recurrence Eight Years and Seven Months after Curative Resection and Favorable Response to Pharmacotherapy-A Case Report].

A 73-year-old woman underwent a descending colectomy for descending colon cancer. The tumor was graded as pStage Ⅲb(pT3[SS], pN1b, pM0, Cur A), according to the 9th edition of the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma. Postoperative treatment of adjuvant chemotherapy comprised oral tegafur/uracil and Leucovorin for 6 months with no evident recurrence. However, contrast-enhanced CT and FDG-PET/CT examination 8 years and 7 months after surgery revealed a 30 mm irregular recurrent tumor in the left iliac fossa. Since the tumor was adjacent to the left psoas muscle, it was considered that RM0(no tumor identified at the radial margin)could not be achieved in that region. Owing to the patient's good general condition, systemic chemotherapy with CAPOX+bevacizumab was administered. Although adverse events prompted discontinuation of the treatment during the first course, the recurrent tumor had significantly regressed. Systemic chemotherapy with mFOLFOX6+bevacizumab as selected subsequent treatment achieved a significant tumor shrinkage to date. Although a recurrence more than 5 years after curative resection of colorectal cancer is extremely rare, the possibility of late recurrence must be considered in patients with well-differentiated tumors who received adjuvant chemotherapy and had negative vascular invasion.