RESUMO
INTRODUCTION AND OBJECTIVE: Most prostate cancers are classified as acinar adenocarcinoma. Intraductal carcinoma of the prostate (IDC-P) is a distinct histologic entity that is believed to represent retrograde spread of invasive acinar adenocarcinoma into prostatic ducts and acini. We have analyzed the impact of IDC-P in hormonal naïve and castration resistant metastatic prostate cancer patients. PATIENTS AND METHODS: We retrospectively evaluated 118 metastatic castration resistant prostate cancer (mCRPC) patients who were initially diagnosed with distant metastases from May 2010 to September 2018. Group 1 patients included 81 metastatic PCa patients with acinar adenocarcinoma and Group 2 included 37 metastatic PCa patients with IDC-P. RESULTS: Mean age at presentation was 76 years (IQR 73.4-78.7) in group 1 and 74 years (68.5-80.6) in group 2. Mean PSA at diagnosis was 619â¯ng/mL (IQR 85-1113) and 868â¯ng/mL (IQR 186-1922), respectively. Time to castration resistance was 24.7 months (IQR 16.7-32.7) in group 1 and 10.2 months (IQR 4.2-16.2) in group 2 (Pâ¯=â¯.007). Time to progression in CPRC patients was: 10.6 months (IQR 5.6-15.6) and at 6.2 months (3.2-9.2), respectively (Pâ¯=â¯.05). Overall survival was 57.9 months in group 1(CI 95% 56.4-59.5) and 38 months (CI 95% 19.9-48.06) in group 2 (Pâ¯=â¯.001). In the multivariate analysis, adenocarcinoma subtype was statistically significant P .014, CI 95% (HR 0.058, 0.006-0.56) CONCLUSIONS: IDC-P seems to be a subtype of prostate cancer that is associated with a shorter response to hormonal treatment when compared to acinar adenocarcinoma in metastatic patients. New drugs in CRPC scenario as abiraterone and enzalutamide also obtained less response in IDC-P patients. Once IDC-P is identified, clinicians could extrapolate the relative poor response to hormonal therapy. Consequently, follow-up of these patients in this scenario should be more strict.