The prognostic value of hemoglobin change after initiating androgen‐deprivation therapy for newly diagnosed metastatic prostate cancer

Abstract

The objective of this study was to characterize changes in hemoglobin (HGB) levels after the initiation of androgen-deprivation therapy (ADT) in patients with previously untreated, metastatic prostate cancer who were enrolled in a large clinical trial. The multivariate associations between 3-month change in HGB and baseline characteristics were evaluated with a linear regression model. The associations between 3-month change in HGB level and time-to-event outcomes, including overall survival and progression-free survival, were evaluated by using proportional hazards regression models. Quartiles of baseline HGB levels were < or =12.0 g/dL, from 12.1 to 13.7 g/dL, from 13.8 to 14.7 g/dL, and >14.7 g/dL. Overall, 3 months after initiating ADT, the mean HGB level declined 0.54 g/dL (standard deviation [SD], 1.68 g/dL); however, the mean HGB level increased by 0.99 g/dL (SD, 1.83 g/dL) in patients who had baseline HGB levels or =12 g/dL. After adjusting for potential confounders, including baseline HGB level, a decline in HGB after 3 months of ADT was associated independently with shorter survival (hazards ratio [HR], 1.10 per 1 g/dL decline; P = .0035) and shorter progression-free survival (HR, 1.08 per 1 g/dL decline; P = .013). An unexpected finding was that the effect of baseline HGB on overall and progression-free survival varied significantly by race. In a sample of men with newly diagnosed, metastatic prostate cancer, a decline in HGB level after 3 months of ADT was associated with shorter survival and progression-free survival after adjusting for disease status and other baseline covariates. Although race alone was not a strong predictor of death or disease progression, the effect of the baseline HGB level on overall and progression-free survival varied significantly by race.