Prostate cancer invading the rectum: a clinicopathological study of 18 cases.

摘要

AIMS: Prostate cancer may involve the rectum and cause severe perineal pain. The aim of this study was to understand the rectal involvement by prostate cancer and its clinical significance. METHODS: We evaluated pathological and clinical features of 18 cases of prostate cancer with rectal involvement. RESULTS: All patients presented with intractable perineal pain. Twelve patients received rectal biopsies, which revealed poorly differentiated prostatic adenocarcinoma (n = 6), squamous cell carcinoma (n = 3), angiosarcoma (n = 1), or no tumour (n = 2). All patients received palliative total pelvic exenteration, which demonstrated prostate cancer invading the rectal wall. In these resection specimens, the tumour consisted of poorly differentiated prostatic adenocarcinoma (n = 16), squamous cell carcinoma (n = 1), or angiosarcoma (n = 1). In addition, six cases of prostatic adenocarcinomas also showed focal squamous (n = 3) or high-grade neuroendocrine (n = 3) differentiation. Nine patients died at a mean time of 18 months (range, 2-69 months) after surgery. The remaining nine patients were alive with a mean follow-up time of 15 months (range, 3-34 months), but four patients developed distant metastases. CONCLUSIONS: Prostate cancer with rectal involvement often develops heterogeneous differentiation and carries a dismal prognosis.