Role of radiotherapy in ductal (endometrioid) carcinoma of the prostate

Abstract

Ductal carcinoma of the prostate is a rare variant of prostate cancer that presents most commonly with obstructive urinary symptoms or hematuria. This case series of 6 patients is the first to report the outcome of ductal carcinoma treated with external beam radiotherapy. A retrospective review was performed of patients treated between 1980 and 2006 at Fox Chase Cancer Center, Philadelphia, Penn. Six patients were identified with ductal carcinoma. Five of the 6 patients were treated definitively and the sixth patient was treated at recurrence 3 years after a radical prostatectomy. Patient ages ranged from 66-80 years and the initial prostate-specific antigen (iPSA) ranged from 1.69-100.3 ng/mL. Three patients had a mixed acinar and ductal carcinoma, 2 with a Gleason score (GS) of 8 and 1 with a GS of 7. Of the patients treated definitively, 4 had clinical stage T2A-T2C and 1 had clinical stage T1B. Definitive radiotherapy was delivered to the prostate with doses between 72 Gy and 78 Gy. Pelvic lymph nodes were treated in all patients. One patient was treated postradical prostatectomy to the prostate bed to a dose of 60 Gy. Adjuvant androgen deprivation was given in 5 of the patients. Two of the patients died from metastatic disease at 1.4 and 7.1 years after treatment. The remaining 4 patients remain alive between 3.2 and 4.8 years from treatment, with 3 patients biochemically without evidence of disease. No patients have developed a local recurrence. Ductal carcinoma of the prostate may be treated effectively with external beam radiotherapy. Aggressive management is indicated, even with low-volume metastatic disease.