Alpha-fetoprotein-producing rectal cancer successfully responded to preoperative chemoradiotherapy: case report

BACKGROUND: Alpha-fetoprotein (AFP) is produced by some tumors, such as hepatocellular carcinoma and yolk sac tumors, leading to an increase in serum AFP level. However, AFP in colorectal cancer is extremely rare. Treatment for AFP-producing cancer is often performed according to conventional methods, but oncological outcomes of both surgery and chemotherapy are poor. We report a case of a patient with AFP-producing rectal cancer which successfully responded to preoperative chemoradiotherapy. CASE PRESENTATION: Rectal tumor was diagnosed in a 68-year-old man referred to our hospital. Colonoscopy showed a type 2 tumor in the lower rectum, and biopsy revealed an adenocarcinoma with enteroblastic differentiation. Serum tumor marker levels were 8.8 ng/ml in carcinoembryonic antigen (CEA) and 28.3 ng/ml in AFP. Clinical diagnosis was stage IIIB (T3N1M0), and preoperative chemoradiotherapy was performed to prevent local recurrence. Effective tumor reduction was observed, and serum tumor marker levels decreased to normal range. Low anterior resection with temporary diverting ileostomy was performed, and histology revealed residual adenocarcinoma. Pathological diagnosis was stage I (T2N0M0). The tumor was found to be an AFP-producing adenocarcinoma on further immunohistopathological examination. The postoperative course was uneventful, and the patient received adjuvant chemotherapy for 3 months. CONCLUSIONS: The outcomes of preoperative chemoradiotherapy against AFP-producing rectal cancer are reported here for the first time. Based on our experience with this patient, it appears preoperative chemoradiotherapy for patients with AFP-producing advanced rectal cancer is feasible.