Patterns of Declining Use and the Adverse Effect of Primary Androgen Deprivation on All-cause Mortality in Elderly Men with Prostate Cancer.

BACKGROUND: Primary androgen deprivation therapy (pADT) is commonly used to treat elderly men diagnosed with localized prostate cancer (CaP), despite the lack of evidence supporting its use.

OBJECTIVE: To examine the effect of pADT on mortality and to assess contemporary trends of pADT use in elderly men with CaP.

DESIGN, SETTING, AND PARTICIPANTS: Men older than 65 yr residing in Surveillance, Epidemiology, and End Results (SEER) registry areas diagnosed with localized or locally advanced CaP between 1992 and 2009 and not receiving definitive therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Propensity score (PS)-weighted Cox proportional hazards models were used to estimate the effect of pADT use on overall survival among patients receiving pADT. The interaction between comorbidity-adjusted life expectancy (LE) and pADT use was assessed within the Cox and PS-weighted models. Contemporary (2004-2009) trends for pADT use were analyzed by linear regression.

RESULTS AND LIMITATIONS: The primary cohort included 46 376 men, of whom 17 873 received pADT (39%). Patients with >10 yr LE had lower pADT utilization rates than patients with short LE. Between 2004 and 2009, the use of pADT in men with localized CaP decreased by 14% (from 36% to 22%). Relative to observation, pADT was associated with a survival disadvantage, with a hazard ratio for all-cause mortality of 1.37 (95% confidence interval 1.20-1.56). Limitations included biases not accounted for by the PS-weighted model, changes in CaP staging over the study period, the absence of prostate-specific antigen (PSA) data prior to 2004, and the limits of retrospective analysis to demonstrate causality.

CONCLUSIONS: The use of pADT in elderly men with localized CaP has decreased over time. For men forgoing primary definitive therapy, the use of pADT is not associated with a survival benefit compared to observation, and denies men an opportunity for cure with definitive therapy. The deleterious effect of pADT is most pronounced in men with prolonged LE.

PATIENT SUMMARY: In this report, we assessed the effect of primary androgen deprivation (pADT) on prostate cancer mortality and determined current trends in the use of pADT. We showed that use of pADT in men aged >65 yr with localized prostate cancer has decreased over time. We also found that pADT is detrimental to men with localized prostate cancer, and particularly men with longer life expectancy. Therefore, we conclude that ADT should not be used as a primary treatment for men with prostate cancer that has not spread beyond the prostate.