Background: The progression to endocrine therapy-resistant prostate cancer is partly due to clonal change to neuroendocrine cell tumor. To elucidate this pathologic process, the clinical courses of four cases of neuroendocrine cell tumor that were found at autopsy are reported.
Methods: Between 1995 and 1999, autopsies were performed for 20 cases of prostate cancer. Lesions predominantly composed of a neuroendocrine cell tumor (small cell carcinoma) were found in four men. The clinical courses of these cases were compared to 16 other non-neuroendocrine cell tumors (adenocarcinomas).
Results: The outstanding features of the neuroendocrine cell tumors were: (i) survival was brief after relapse, although the duration of control by employing endocrine therapy varied; (ii) the prostate-specific antigen level did not increase after relapse; and (iii) the sites of metastasis were similar to those of common adenocarcinomas.
Conclusion: The progression to a neuroendocrine cell tumor indicated a poor prognosis and slight (if any) changes in the serum prostate-specific antigen level. This tumor might not appear to respond to any therapeutic attempt.