Abstract
Endocrine cell carcinoma (ECC) of the rectum is a rare neoplasm usually associated with a poor prognosis. No standard chemotherapeutic regimens exist for the treatment of ECC. We encountered a case of rectal ECC in which chemotherapy was administered based on the results of a chemosensitivity test, the collagen gel droplet–embedded culture drug sensitivity test (CD–DST). A 64–year–old man with anal pain was diagnosed with rectal cancer. The patient received Mile's operation and was microscopically diagnosed as having ECC with foci of differentiation to adenocarcinoma. Multiple hepatic metastases were found 1 month after surgery. The patient received TEGAFIRI (oral UFT and leucovorin with irinotecan), which was intermediately sensitive based on the CD–DST. TEGAFIRI initially reduced the extent of hepatic metastases, indicating a partial response after 3 months of administration. However, progress of the disease was confirmed and TEGAFIRI had become ineffective after 5 months of administration. Thereafter, although mFOLFOX6 with bevacizumab, which was insensitive based on the CD–DST, was administered, the progression of hepatic metastases continued, indicating progressive disease. The patient died 13 months after surgery. In conclusion, we suggest that CD–DST may be useful for identifying sensitive antitumor agents for the treatment of rectal ECC for which no standard chemotherapeutic regimens exist.
