Lowering the biopsy threshold for prostate cancer from a PSA of 4.0 to 2.5 would increase the risk of overdiagnosis and overtreatment, according to this first large-scale study of current treatment patterns in the U.S. population.
Thanks to early detection and treatment, since 1975, there have been significant gains in survival rates for prostate cancer at all stages. But concerns regarding overtreatment have also increased; prostate cancer treatments themselves can present serious adverse effects for patients. This study used national epidemiological data to examine characteristics and treatment patterns of almost 124,000 men, newly diagnosed with prostate cancer from 2004 to 2006 across the U.S.
- Fourteen percent of prostate cancers were diagnosed among men with PSA levels of 4.0 or lower. More than half of these patients were classified as having low-risk cancer; this group, overall, was less likely to have high-grade cancer.
- Despite these lower risks, treatment patterns for these men were comparable to patterns among men with PSA levels between 4.0 and 20.0; over 75 percent underwent “attempted curative therapy,” which is either radiation therapy or a radical prostatectomy.
- Based on these findings, if the “abnormal” PSA threshold were lowered from 4.0 to 2.5, another 1.9 million men would be “diagnosed;” 82.5 percent of them would seek curative treatments; and only 2.4 percent would have high-grade cancers. No evidence suggested that delaying biopsy until the PSA reached 4.0 would result in an “excessive number” of noncurable cases.
This study indicates many men are already receiving treatments that may not provide them with benefit but do expose them to increased risk of adverse effects. The problem of overdiagnosis and overtreatment would increase if the abnormal PSA threshold were lowered from 4.0 to 2.5. Without the ability to distinguish between aggressive and nonaggressive cancers, lowering the PSA threshold may make patients and doctors too vigilant.