Few Younger Patients

Andriole also noted in a news release that fewer than 10% of men in the study were in their 40s and 50s, not enough to determine whether surgery would lower mortality in that group.

“While the study demonstrates that some men with low-grade disease may not benefit from surgical intervention, it does not add to our understanding of who exactly these men are,” Penson added. “This is due in no small part to the fact that only 10% of the men in PIVOT were under age 60, and only half of the patients (55%) had no other co-morbid conditions. Given that the median follow-up in PIVOT was only 10 years and the real possibility that patients with low-grade prostate cancer and longer life-expectancies may garner some benefit from surgical treatment with longer follow-up, younger, healthier patients with low-grade prostate cancer should still strongly consider surgical treatment for their disease."

Despite objections from the urology group, PIVOT’s findings support the results of the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer-screening trial, which to date has shown that most cancers detected by repeated PSA screening are low risk and that annual prostate cancer screening does not reduce mortality.

“The findings of these two studies should be reassuring to men with low-risk prostate cancer,” said Andriole, who also serves as chairman of the PLCO’s prostate cancer committee. “PSA screening commonly results in the discovery of cancers that are generally not a threat to life. This ‘overdiagnosis’ of nonlethal cancers is concerning in and of itself and becomes especially problematic if men with such low-risk cancers are ‘overtreated,’ since they are unlikely to benefit from the treatment and may experience side effects like incontinence and impotence.”

Overall, deaths from prostate cancer occurred infrequently during the study period. Only 5.8% of those treated with surgery died of prostate cancer or treatment, compared with 8.4% of those under observation — not a statistically significant difference.

In recently assigning PSA screening a Grade D recommendation and discouraging its use, the U.S. Preventative Services Task Force considered results of both the PLCO and PIVOT studies.

Andriole suggested a middle ground for many men with low-risk prostate cancer detected by PSA screening.

“Active surveillance is apt to be better than observation or immediate treatment in most low-risk patients,” he said. “We watch the PSA very closely and biopsy men periodically, so, if a tumor starts growing or becomes more aggressive, we can still successfully treat it.”

Penson, meanwhile, said the inability to conclusively determine whether prostate cancer is low- or high-risk makes it difficult to discourage treatment in patients who want it.

He said the data about “positive findings in the high-risk patients underscore a strong need for reliable, effective biomarkers that allow us to distinguish low-risk disease from high-risk disease, so we can prescribe treatment accordingly. Until we are able to distinguish between indolent and aggressive disease, some men with low-risk prostate cancer will desire treatment; this is appropriate in the absence of a certainty that they will die with prostate cancer, not of prostate cancer.

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