What’s known about the characteristics of men being treated aggressively for prostate cancer? Up to now, not much. A study published in the Archives of Internal Medicine describes “the first large-scale US population-based study to document the risk profiles and treatment patterns among men with PSA levels of 4.0 ng/mL or lower who were diagnosed as having prostate cancer.” Between 2004 and 2006, about 14 percent of prostate cancer diagnoses fell into this category. Such men are considered less likely to have more worrisome, high-grade cancer and more than half were classified as having low risk cancer.
But despite the lower risk, treatment rates for these men were comparable to those of men with PSA scores between 4.0 and 20.0 ng/mL.
The researchers wrote:
“The finding that men in low-risk groups were treated intensively raises the concern of overtreatment, especially among older patients.”
It’s interesting to now have some idea of how many men get conservative treatment – about 25 percent – receiving neither radical prostatectomy nor radiation therapy as their primary treatment. There wasn’t good data on the use of hormone therapy.
The researchers conclude:
Recently publicized results from the European Randomized Study of Screening for Prostate Cancer show that 1410 men would need to be screened and 48 additional cases of prostate cancer would need to be treated to prevent 1 death from prostate cancer. Given that US patients are in general diagnosed at earlier stages and are more likely to receive attempted curative therapy, the number needed to treat to save 1 patient is likely to be higher in the United States than in Europe.
Based on the recent update of the Scandinavian Prostate Cancer Group Study Number 4 trial, men 65 years or older treated with RP fared no better than men undergoing conservative management. Our results demonstrate that 66% of men aged between 65 and 74 years with low-risk disease and a PSA value of 4.0 ng/mL or lower received either radical prostatectomy or radiation therapy. These findings suggest that many contemporary men receiving treatment for localized prostate cancer are unlikely to benefit from the intervention. Furthermore, it has been documented that men who receive any treatment have increased risk of treatment-related adverse effects.Therefore, it is critical that patients be counseled about treatment-associated adverse effects and benefits when they are deciding about therapy.
The number of men with “abnormal” PSA levels would double to approximately 6 million if the threshold were decreased from 4.0 to 2.5 ng/mL. Estimates suggest that 32% of men with abnormal PSA levels would be diagnosed as having prostate cancer from their needle biopsy. Based on the results in the present study, 82.5% of these 1.9 million men would receive attempted curative treatments, while only 2.4% would have high-grade cancer. However, no evidence suggests that delaying biopsy until the PSA level reaches 4.0 ng/mL would result in an excessive number of potentially noncurable disease cases. Although abandoning an upper limit of normal for PSA level would allow physicians to detect more cancer, the benefits of diagnosing prostate cancer would likely be offset by treatment complications related to cancers that might never have caused harm.
Our study found that aggressive local therapy was provided to most patients diagnosed as having prostate cancer. These results underscore the fact that PSA level, the current biomarker, is not a sufficient basis for treatment decisions. Without the ability to distinguish indolent from aggressive cancers, lowering the biopsy threshold might increase the risk of overdiagnosis and overtreatment.