Autori: S. Oudard, E. Banu, A. Banu, F. Scotte, E. Levy, C. Maignan, J. Andrieu

Editorial: Poster presentation. Abstract 1673. Proc Am Soc Clin Oncol 2003;22:416., 2003.

Rezumat:

Objective: PSA decrease is a surrogate endpoint for response in HRPC patients (pts) treated with chemotherapy (CT). This study aimed to assess the correlation between PSAHT dynamics with overall survival (OS) and time to PSAHT failure (TTF) in pts receiving CT for metastatic HRPC and to identify new predictive response categories.
Methods: From 2000 to 2002, 121 pts were randomized: 42 pts to docetaxel (D) 70 mg/m2 day 1, 21 + estramustine (arm A); 39 pts to D 35 mg/m2 day 1, 8, 21 + estramustine (arm B) and 40 pts to mitoxantrone 12 mg/m2 (arm C). PSAHT was assessed using log linear regression on all PSA values. Pts had monthly PSA evaluations from randomization until death or last evaluation. The failure point was the 2nd increased PSAHT value after nadir, confirmed by a 3rd determination. PSAHT TTF was the time between first PSA evaluation and the failure point. Based on their likelihood of biochemical failure, pts were categorized as: responders (R) and non-responders (P), defined by initial-progressors (IP) or late-progressors (LP). IP pts had negative PSAHT values. For LP pts, the first point was positive and considered as nadir.
Results: Median PSAHT nadir was 30.5 days (range 9-1445). There was no correlation between PSAHT TTF and Gleason grade or PSA level at baseline. A significant difference was observed between PSAHT TTF and treatment arms (A, B and C) for R pts, {19 (45%), 17 (44%) and 6 (15%); P=.005} and for IP pts {6 (14%), 8 (21%) and 22 (55%); P=.00001}. There was no correlation between PSAHT TTF and treatment arms for LP pts. The PSAHT TTF correlated significantly with the response groups: median time was 4, 2.3 and 1 months in R, LP and IP groups, respectively (P=.000001). OS was 18.6, 18.2 and 12.7 months in R, LP and IP groups, respectively (P=.02).
Conclusion: Decrease of PSAHT during CT represents an accurate parameter for predicting treatment response. Optimal duration of CT should be based on the PSAHT dynamics. As PSA changes alone do not currently meet surrogate criteria, we believe that our definition is worth using in trials for pts with HRPC.

Cuvinte cheie: timp de injumatatire PSA, cancer de prostata, supravietuire // PSA half-time, prostate cancer, survival

URL: http://www.asco.org/portal/site/ASCO/menuitem.34d60f5624ba07fd506fe310ee37a01d/?vgnextoid=76f8201eb61a7010VgnVCM100000ed730ad1RCRD&vmview=abst_detail_view&confID=23&abstractID=102500