Effect of androgen deprivation therapy on intraductal carcinoma of the prostate (IDC-P), a prognostic factor for prostate cancer.

146 Background: The presence of intraductal carcinoma of the prostate (IDC-P) is reported to be an adverse prognostic factor for cancer-specific survival (CSS) in localized and metastatic prostate cancer patients. However, there is no data indicating whether the presence of IDC-P can be affected by ADT (androgen deprivation therapy). Methods: We retrospectively evaluated 152 high risk prostate cancer patients who underwent radical prostatectomy with neoadjuvant ADT. They were diagnosed and treated at author-affiliated hospitals between 1991 and 2005. All patient data was made available from slides prepared from prostate needle biopsy samples and prostatectomy specimens and each patient received ADT before operation. Slides were re-reviewed by a single genitourinary pathologist (T.T.) according to the 2005 International Society of Urological Pathology (ISUP) grading system and presence of IDC-P was defined using previously published diagnostic criteria. Results: Patient median age was 68 years (range 46-80 years). The median iPSA was 32.7 ng/ml (range 2.4-296). The median follow-up period was 109 months (range 11-257). Sixty-one patients (40%) were ≥cT3 and 113 cases (74%) had biopsy Gleason score ≥8. Preoperative median ADT period was 4 months (range 1–20 ). IDC-P component was detected in 54 patients (36%) in needle biopsy and 69 (45%) in prostatectomy. There were 28 patients who died of the disease and 12 patients who died of other causes during follow-up. They were divided in 4 groups according to with or without IDC-P in biopsy/prostatectomy (-/- 68cases ,-/+ 30, +/- 15, +/+ 39). Twenty eight per cent of IDC-P positive cases in biopsy showed disappearance of IDC-P in prostatectomy specimen. Prognosis was the worst in +/+ group and IDC-P disappearance cases (+/-) tended to have better survival than IDC-P existing cases (+/+) in CSS (p = 0.04). Conclusions: In a number of IDC-P-positive cases determined by needle biopsy, the disappearance of IDC-P in prostatectomy specimens after ADT indicates the possibility that part of IDC-P positive patients can occasionally respond to ADT.