The complete results of the Prostate Cancer Intervention versus Observation Trial (PIVOT) study have (finally) just been published in the New England Journal of Medicine. Unfortunately, only the abstract is available on line so it may take us a little while to get hold of a copy of the complete report.
For those who may have forgotten (or simply not been aware of this study), this was a long-term study of the relative benefits (and risks) of radical prostatectomy to simple “observation” (effectively a watchful waiting strategy as opposed to an active surveillance strategy) in men initially diagnosed with localized prostate cancer.
According to the abstract (and as previously reported):
- The trial enrolled 731 men with localized prostate cancer between November 1994 and January 2002.
- These 731 men were randomly assigned to either be treated with a radical prostatectomy (RP) or were simply “observed.”
- All patients were followed until January 2010.
- The primary study outcome was all-cause mortality.
- The secondary study outcome was prostate cancer-specific mortality.
The core results of the study are as follows:
- Average (mean) age of the patients at enrollment was 67 years.
- Average (median) PSA level of the patients at enrollment was 7.8 ng/ml.
- Average (median) follow-up was 10.0 years.
- During the follow-up period
- 171/364 patients (47.0 percent) randomized to RP died.
- 183/367 patients (49.9 percent) randomized to observation also died.
- The absolute reduction in risk of death as a consequence of RP as opposed to observation was 2.9 percent (hazard ratio [HR] = 0.88).
- 21/364 patients (5.8 percent) randomized to RP died either from their prostate cancer or as a direct consequence of their treatment.
- 31/367 patients (8.4 percent) randomized to observation died from prostate cancer.
- The absolute reduction in risk of death as a consequence of RP as opposed to observation was 2.6 percent (HR = 0.63).
- Adverse events after surgery occurred within 30 days in 21.4 percent of patients treated by RP, inclusive of one death.
- Among men with a baseline PSA > 10 ng/ml, RP was associated with a statistically significant reduction in risk for all-cause mortality.
- Among men with intermediate-risk or high-risk prostate cancer there appears to have been the possibility of a statistically significant reduction in risk for all-cause mortality.
- There was no impact of treatment on all-cause and prostate-cancer mortality according to age, race, coexisting conditions, self-reported performance status, or histologic features of the tumor.
The authors conclude with the careful statement that:
Among men with localized prostate cancer detected during the early era of PSA testing, radical prostatectomy did not significantly reduce all-cause or prostate-cancer mortality, as compared with observation, through at least 12 years of follow-up.
There appear to be no important differences in the final abstract of this paper as compared to data originally reported by Wilt at the annual meeting of the American Urological Association in May 2011, which only makes it more surprising that it has taken so long for this report to be published.
We will reserve further comment on this paper until we have had the chance to read the entire text of the article, as well as the entire text of the associated editorial by Thompson and Tangen entitled “Prostate cancer — uncertainty and a way forward.” More information is available in a commentary already available on the MedPage Today web site. (They clearly had early access to the full text of the article and the associated editorial.)