New research suggests that relaxed guidelines on prostate cancer screening may hamper diagnosis and treatment of tumors and cancers.
The United States Preventive Services Task Force (USPSTF) in October 2011 recommended against prostate-specific antigen-based (PSA) screening to limit the overdiagnosis as well as overtreatment of prostate cancer.
A study published in the Journal of Urology found a 28 percent decrease in incident diagnoses in the year after the guidelines on PSA screening were implemented.
Lead researcher Dr. Daniel Barocas, assistant professor of urologic surgery at Vanderbilt University in Nashville, Tennessee, said the guidelines had a beneficial effect as there are low-risk cancers that most men will not die of and where treatment can do more harm than good.
"On the negative side, we seem to be missing intermediate and high-risk cancers in men who would be eligible for treatment," Barocas said, warning against "missed opportunities" in identifying and treating the disease.
Published in June this year, the study identified cancers diagnosed between January 2010 and December 2012 in the National Cancer Database. Monthly prostate cancer diagnoses decreased by 1,363 cases (12.2 percent) in the month after the USPSTF recommendations, continuing to drop by an overall 28 percent. The decreases were similar for all races, ages, income and insurance.
In the year following the guidelines, diagnoses of new low-risk cancers decreased by 38 percent, falling more rapidly than the diagnoses of more aggressive ones—a suggestion of the guidelines’ "intended effect" on low-risk cancers.
USPSTF Vice-Chair Dr. Kirsten Bibbins-Domingo said that the task force found "a very small potential benefit and significant potential harms" in 2011 when it reviewed evidence on PSA screening for prostate cancer. She explained that there is no way at present to know which cancers likely threaten men's health and which do not.
Dr. Barocas disagreed, stressing that there are men who are at high risk for prostate cancer and should be properly screened. Men in this category include those with a family history of prostate cancer and black males.
He added that while low-risk cancer need not be treated but simply monitored, high-risk cancer should be treated after screening.
When the guidelines were published, new techniques—including magnetic resonance imaging and ultrasound—have been developed to diagnose prostate cancer more correctly and differentiate between low- and high-risk cancers.
