A competing-risks analysis of survival after alternative treatment modalities for prostate cancer patients: 1988-2006

The efficacy of prostate cancer (PCa) treatment modalities is a subject of continuous debate.

We tested the hypothesis that significant differences in survival rates may exist among PCa patients treated with radical prostatectomy (RP), radiation therapy (RT), and observation.

We focused on 404,604 patients with clinically localized PCa within 17 Surveillance, Epidemiology and End Results registries.

Competing-risks survival analyses were used to estimate cancer-specific mortality (CSM) and other-cause mortality (OCM) rates. Patients were stratified according to treatment type, age group, and PCa risk group (high risk: T2c and/or Gleason score 8-10; low to intermediate risk: all others).

The 10-yr CSM and OCM rates were 6.1% and 29.2%, respectively. In RP, RT, and observation patients, CSM rates were 3.6%, 6.5%, and 10.8% (p<0.001), respectively; OCM rates were 17.1%, 32.4%, and 48.9% (p<0.001), respectively. In low- to intermediate-risk patients, the lowest CSM (1.3-3.7%) and OCM (6.9-31.6%) rates within all age categories except octogenarians (8.9% and 62.8%, respectively) were recorded in RP. In high-risk patients, the lowest CSM (5.8-7.2%) and OCM (8.7-16.1%) rates in patients aged ≤69 yr were also recorded in RP. RT was equally favorable to RP in the 70-79 age category and appeared ideal in all octogenarian patients.

Our results showed that RP provides the most favorable survival rates in most patients. The exception is octogenarian men, in whom RT provides the best results. Finally, the least-favorable outcomes were recorded after observation. However, these findings must be interpreted within the context of the limitations of observational data.