We aimed to identify clinical predictors of long-term response to abiraterone (defined as >12 months drug exposure) in a retrospective cohort of metastatic castration-resistant prostate cancer patients treated in post-docetaxel setting at 24 Italian centers. The Cox proportional hazards model was used to analyze the association between clinical features and the duration of drug exposure. Results were expressed as hazard ratios (HR) with associated 95% confidence intervals (CI). A total of 143 patients met the inclusion criteria. Their median age was 73 years, median Gleason score 8 and median abiraterone exposure 20 months. At the univariate analysis, a significant correlation with the duration of abiraterone exposure was found for Gleason score (HR 0.82, 95% CI 0.71-0.96; p=0.012), PSA (HR 1.10, 95% CI 1.03-1.18; p=0.08) and lactic dehydrogenase levels (HR 1.22, 95% CI 1.02-1.46; p=0.027), while the association between lower alkaline phosphatase levels and treatment duration was marginally significant (HR 1.07, 95% CI 0.99-1.16; p=0.074). Only PSA and Gleason score were predictive of long-term treatment duration in the multivariate analysis. No other clinical factors resulted to be predictive of sustained response to abiraterone, including metastatic disease at diagnosis and visceral disease, suggesting that all subgroups of patients may derive a substantial clinical benefit from abiraterone treatment. These findings need to be validated in prospective, larger studies.
Oncotarget. 2016 May 19 [Epub ahead of print]
Elena Verzoni, Ugo De Giorgi, Lisa Derosa, Orazio Caffo, Francesco Boccardo, Gaetano Facchini, Luca Porcu, Fabio De Vincenzo, Alberto Zaniboni, Vincenzo Emanuele Chiuri, Lucia Fratino, Daniele Santini, Vincenzo Adamo, Rocco De Vivo, Angelo Dinota, Caterina Messina, Riccardo Ricotta, Claudia Caserta, Claudio Scavelli, Marina Susi, Alfredo Tartarone, Giuseppe Surace, Alessandra Mosca, Michele Bruno, Sandro Barni, Paolo Grassi, Giuseppe Procopio
Medical Oncology 1, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy., Department of Medical Oncology, I.R.S.T.-IRCCS, Meldola, Italy., Medical Oncology 2, Istituto Toscano Tumori, Pisa, Italy., Ospedale Santa Chiara, Trento, Italy., IRCCS AOU San Martino IST and University of Genoa, Italy., Medical Oncology, Department of Uro-Gynecological Oncology, Istituto Nazionale Tumori, Fondazione G. Pascale IRCCS, Naples, Italy., Department of Oncology, IRCCS- Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy., Istituto Clinico Humanitas, Rozzano, Italy., Fondazione Poliambulanza, Brescia, Italy., Ospedale Vito Fazzi, Lecce, Italy., Istituto Nazionale Tumori CRO, Aviano, Italy., Policlinico Universitario Campus Biomedico, Roma, Italy., Medical Oncology Unit, AO Papardo, Messina, Italy., Ospedale San Bortolo, Vicenza, Italy., Ospedale San Carlo, Potenza, Italy., Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy., Niguarda Cancer Center, Ospedale Niguarda Ca' Granda, Milan, Italy., AO Santa Maria, Terni, Italy., Ospedale S. Cuore di Gesù, Gallipoli, Italy., Ospedale Madonna delle Grazie, Matera, Italy., IRCCS Centro di Riferimento Oncologico della Basilicata (CROB), Rionero in Vulture, Italy., Ospedale D. Camberlingo, Francavilla Fontana, Italy., AOU Maggiore della Carità, Novara, Italy., PO San G. Moscati, ASL Taranto, Italy., AO Treviglio, Italy., Medical Oncology 1, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy., Medical Oncology 1, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.