α‐fetoprotein‐producing rectal cancer: Calculated tumor marker doubling time

alpha-fetoprotein (AFP) production by rectal cancer is very rare. In the English literature there are only a few reported cases in which serum AFP level was > 1,000 ng/ml. A 43-year-old Japanese man with rectal cancer and liver metastases had a high serum AFP level (941 ng/ml) when first evaluated. Three weeks later, the serum AFP level was extremely elevated (7,060 ng/ml). He underwent abdominoperineal excision of the rectum and biopsy of liver metastases. The placement of an intrahepatic-arterial infusion catheter into the proper hepatic artery via the right gastroepiploic artery was also performed. Immunohistochemically, AFP-positive cells were identified in both the rectal and liver tumors. Nine days postoperatively, the serum AFP level was 2,000 ng/ml. In spite of intensive chemoimmunotherapy, serum AFP level was increased and 14 weeks after surgery was extremely elevated (267,300 ng/ml). The patient succumbed to cancer 3 months after surgery. To our knowledge, this is the first case of an AFP-producing rectal cancer in which AFP doubling time could be calculated as 12.8 days.