[2006] [1197] Prognostic value of hemoglobin change after initiation of androgen deprivations therapy for newly diagnosed metastatic prostate cancer: a multivariate analysis of SWOG 8894

Tomasz M Beer*, Portland, OR; Bryan H. Goldman, Catherine M. Tangen, Seattle, WA; Lisa B Bland, Portland, OR; Maha Hussain, Ann Arbor, MI; Thomas DeLoughery, Portland, OR; E. David Crawford, Aurora, CO.

Introduction and Objective: To characterize hemoglobin (HGB) change after initiation of androgen deprivation therapy (ADT) in a large study of patients with previously untreated metastatic prostate cancer, to determine baseline covariates associated with observed HGB change, and to determine if HGB change after initiation of ADT adds prognostic information. Methods: The multivariate associations between 3-month change in HGB and baseline characteristics were evaluated with linear regression. The associations between 3-month change in HGB level and both overall survival (OS) and progression-free survival (PFS) were evaluated using proportional hazards regression. Results: The median pre-treatment HGB was 13.7 g/dL. Quartiles of baseline HGB were: Q1: ≤ 12.0, Q2: 12.1-13.7, Q3: 13.8-14.7, Q4: > 14.7 g/dL. After 3-months of ADT, the overall mean change in HGB decreased 0.54 g/dL (SD 1.68); however, mean HGB increased by 0.99 g/dL (SD 1.83) in patients with baseline HGB < 12 g/dL but decreased 1.04 g/dL (SD 1.28) in those with baseline HGB > 12 g/dL. In a multivariate analysis, baseline HGB, flutamide treatment, black race, worse performance status, increasing age, and prior radiation therapy were associated with a 3-month decline in HGB level. Baseline PSA, bone pain, extensive disease, prior prostatectomy, and Gleason score had no significant effect. A decline in HGB after 3 months of ADT was independently associated with shorter OS (HR 1.10 per 1 g/dL decline, p=0.0035) and shorter PFS (HR 1.08 per 1 g/dL decline, p=0.013) after adjustment for baseline HGB and other potential confounders. An unexpected finding was that the effect of baseline HGB on overall and progression-free survival varied significantly by race. Below a baseline HGB of 11.7 g/dL black patients had worse overall survival than their non-black counterparts (significant only below 7.8 g/dL). Above 11.7 g/dL, black patients had better overall survival than their non-black counterparts (significant only above 14.2 g/dL). Conclusions: In this newly diagnosed metastatic prostate cancer sample, HGB change after 3 months of ADT was heterogenous and was associated with shorter survival and shorter progression-free survival after adjustment for disease status and other baseline covariates. While race alone was not a strong predictor of death or disease progression, the effect of baseline hemoglobin on overall and progression-free survival varied significantly by race.

Podium: Prostate Cancer: Advanced (II) (10:00 AM-12:00 PM)