medwireNews: All-cause and prostate cancer-specific mortality rates remain comparable over nearly 2 decades of follow-up among men with early prostate cancer regardless of whether they undergo radical prostatectomy or observation, the PIVOT trial shows.
Over 19.5 years of follow-up (median 12.7 years), the cumulative incidence of death due to any cause was 61.3% for the 364 participants (median prostate-specific antigen (PSA) level of 7.8 ng/mL) who were randomly assigned to receive radical prostatectomy and 66.8% for their 367 counterparts who underwent observation, with no significant difference between groups.
Prostate cancer-specific mortality was also comparable, with a cumulative incidence of death attributable to the disease or treatment of 7.4% and 11.4%, respectively.
Subgroup analysis indicated an all-cause mortality benefit for surgery among men with an intermediate D’Amico tumor risk score, with an absolute between-group difference of 14.5 percentage points, but not for those with low- or high-risk disease, at 0.7 and 2.3 percentage points, respectively.
Timothy Wilt (University of Minnesota School of Medicine, Minneapolis, USA) and fellow investigators “urge caution in interpreting subgroup effects,” however, as the study was not powered for such analysis. Moreover, “[b]eneficial effects depend on proper histopathological grading, which is fraught with interobserver and intraobserver variation,” they add.
Radical prostatectomy was associated with significantly lower levels of local, regional, or systemic disease progression during 12 years of follow-up (median 10 years) than observation, at rates of 40.9% and 68.4%, respectively, but the researchers point out that most events were local and asymptomatic.
Men who underwent surgery were also significantly less likely to receive further treatment, with a post-progression treatment rate of 33.5% compared with 59.7% in the observation arm.
But the incidence of urinary incontinence and erectile and sexual dysfunction over 10 years was higher among surgically-treated men than their counterparts who underwent observation.
Men in the radical prostatectomy arm also reported a greater degree of functional limitations and bother due to prostate cancer or its treatment during the initial 2 years, but these differences were not evident at later timepoints.
And worry about health did not vary significantly between treatment groups at any timepoint, according to the report published in The New England Journal of Medicine.
Wilt et al say that the findings from PIVOT and other trials, such as ProtecT, show that “long-term prostate-cancer mortality remains low among most men with localized prostate cancer who are treated with observation and that death from prostate cancer is very uncommon among men with low-risk and low-PSA disease.”
“Reducing overtreatment is needed,” they emphasize.
medwireNews is an independent medical news service provided by Springer Healthcare. © 2017 Springer Healthcare part of the Springer Nature group
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