[Small cell carcinoma of the prostate: a report of three patients and a prognostic analysis of cases reported in Japan].

Small cell carcinoma (SCC) originating from the prostate is rare. We report three cases of SCC of the prostate. Case 1: A 29-year-old man with large pelvic mass and pelvic lymph node metastases was diagnosed as having pure SCC of the prostate. Chemo-radiotherapy resulted in a great reduction of the tumor volume. However, the disease recurred immediately, and he died of disease 17 months after diagnosis. Case 2: A 65-year-old man presented with pure prostatic SCC with lung metastases. Although cystoprostatectomy combined with pre- and post-operative chemotherapy ended with no evidence of disease, he died after 16 months because of multiple metastases and local recurrence. Case 3: A 73-year-old man was diagnosed as having SCC and poorly differentiated adenocarcinoma of the prostate simultaneously. Chemo-endocrine therapy and pelvic irradiation were performed, achieving partial remission. However, he developed multiple distant metastases, and died of disease 15 months after diagnosis. We reviewed 82 cases previously reported in Japan. Patient's ages ranged from 24 to 86 years (mean 68.7 years). Many patients had lymph node or distant metastases (stage D, 73%). Thirty-seven (45%) were pure SCCs and 45 (55%) were associated with adenocarcinoma. The prognosis after the recognition of SCC is very poor, and the 1- and 2-year survival rates were 27% and 10%, respectively. Survival did not differ in patients with pure SCC or mixed glandular and small cell carcinoma. Higher elevation of pretreatment serum NSE value was associated with the poor prognosis.