Observation as Good as Radical Surgery for Localized Prostate Cancer, Especially Low-Risk Cancer
In this era of upwardly spiraling healthcare costs, the management of low-risk prostate cancer is changing. Although approximately two thirds of men with a diagnosis of prostate cancer have a low prostate-specific antigen (PSA) value or low-risk disease, approximately 90% of these men receive early intervention, with surgery or with radiation. Findings from a new study from the Minneapolis Veterans Affairs Health Care System suggest that localized prostate cancer, especially low-risk cancer, can be safely managed by observation alone.
Radical prostatectomy was not significantly better than observation in preventing death from any cause, including prostate-specific death, in men with localized prostate cancer that was detected by PSA, according to the large, randomized Prostate Cancer Intervention Versus Observation Trial (Wilt TJ, et al. N Engl J Med. 2012;367: 203-213).
“Our findings add to evidence supporting observation, and possibly active surveillance, for most men who receive a diagnosis of localized prostate cancer, especially those with a low PSA value or low-risk disease,” wrote the investigators.
Between November 1994 and January 2002, 364 patients were assigned to radical prostatectomy and 367 to observation. All patients (aged ≤75 years) had histologically confirmed localized prostate cancer of any grade diagnosed within the previous year, PSA <50 ng/mL (median at baseline, 7.8 ng/mL), a negative bone scan, and a life expectancy of at least 10 years from randomization. All the men underwent a biopsy to confirm the PSA-based diagnosis. Men assigned to observation were offered palliative therapy or chemotherapy for disease progression.
Based on review of biopsy specimens, 48% of the patients had Gleason scores of ≥7 and 66% had intermediate- or high-risk cancers.
Over a 12-year period (median follow-up, 10 years), 47% of the men who were assigned to radical prostatectomy died versus 49.9% of those assigned to observation alone, for a nonsignificant absolute risk reduction of 2.9% for surgery. The rates of prostate-specific cancer death were 5.8% for surgery versus 8.4% for observation alone, a nonsignificant 2.6% absolute risk reduction favoring surgery.
The effect of radical prostatectomy did not differ by age, race, performance status, coexisting illness, or histologic features of the tumor. Radical prostatectomy appeared to be superior to observation in reducing death from any cause among men with a PSA value >10 ng/mL and in those with intermediate- or high-risk tumors.
“Our study was conducted in the early era of PSA testing. The current practices of performing repeated PSA testing, using a lower PSA threshold for biopsy, obtaining more tissue-biopsy cores, and performing a repeat biopsy…increase the detection of smaller volume indolent cancers,” the investigators wrote. These factors lead to overdiagnosis and overtreatment, they noted.
Among men with intermediate-risk (ie, PSA of 10.1-20 ng/mL; a Gleason score of 7; or a stage T2b tumor) or high-risk prostate cancer, surgery reduced all-cause mortality by 10.5% compared with observation; however, in patients with low-risk disease, observation was favored over surgery.
For prostate cancer–specific mortality, surgery had an advantage compared with observation in men with a PSA value >10 ng/mL at diagnosis and among men with high-risk prostate cancer. No advantage was found with surgery versus observation in men with a PSA value <10 ng/mL.
Perioperative complications in the first 30 days after surgery were reported in 21.4% of men who underwent a radical prostatectomy. At 2 years, urinary incontinence and erectile dysfunction rates were significantly higher with surgery than with observation.