BALTIMORE—Primary androgen deprivation therapy (PADT) does not prolong survival as much as radical prostatectomy (RP) among men with localized prostate cancer (PCa), a new retrospective analysis has confirmed.
The results were released at the International Society for Pharmacoeconomics and Outcomes Research’s 2011 annual meeting.
Researchers led by Jinan Liu, MD, analyzed data from PCa patients at Veterans Administration facilities throughout eight southeastern states. The men underwent PADT or RP within six months of diagnosis.
A total of 426 men in this sample were aged between 18 and 75 years at treatment initiation and had no other previous cancer diagnosis. From among these patients, the investigators performed propensity score matching on 123 patients in each group.
The researchers based the matching on age, race, marital status, whether the person had non-VA insurance coverage, cancer stage, Charlson Comorbidity Index score and tobacco, and alcohol use.
After the matching, the team found that the cumulative incidence of death was 10.6% among men who underwent PADT and 3.3% among RP patients during a median follow-up of 4.3 years and 4.2 years, respectively. The three-year overall survival was 92.7% among PADT patients and 98.4% among those who underwent RP. PADT patients more three times more likely to die than RP patients
None of the other variables the investigators analyzed were statistically significantly different between the two groups.
Matthew Cooperberg, MD, MPH, Assistant Professor of Urology at the University of California at San Francisco, led the recent CaPSURE study, which also found ADT is associated with shorter survival than RP (Cancer. 2010;116:5226-5234). However, the VA study was based on administrative data and could not adjust for differences among patients receiving each treatment, which could in part explain the survival differences. Therefore, the study cannot supply a definitive answer to the question of whether or not ADT is associated with worse survival than prostatectomy, Dr. Cooperberg said.
“In our study, as well as in a recent study on the same subject from Memorial Sloan-Kettering Cancer Center, we had enough data on each patient to allow us to conduct a careful risk adjustment,” Dr. Cooperberg told Renal & Urology News. “The VA study doesn’t have a lot of detail about the tumors, such as stage, or PSA or Gleason scores. … Nonetheless, the findings are consistent with ours, and add to a growing body of evidence on comparative effectiveness of treatments for localized prostate cancer.”
Dr. Liu said he agrees with these comments, but noted that his team’s study helps “draw more attention to PADT overuse among localized prostate cancer patients, especially in the VA population.” He added that his team is now using Surveillance, Epidemiology and End-Results (SEER)-Medicare data to conduct a similar comparison using more complete data from each patient.