The American Society for Radiation Oncology (ASTRO) has praised the U.S. Preventative Services Task Force (USPSTF) for offering a recommendation on the use of prostate-specific antigen (PSA)-based screening for prostate cancer, but cautioned against a blanket no-testing policy.
The USPSTF has recommended against PSA-based screening, assigning it a grade D designation, meaning the service has no net benefit or that the harms outweigh the benefits. The full text of the recommendation explained that evidence is strong that PSA-based screening leads to substantial overdiagnosis of prostate tumors.
“Overdiagnosis is of particular concern in prostate cancer because a high percentage of men are treated at the time of diagnosis, and a man with an indolent lesion may experience any of the associated harms of a therapy but cannot benefit, by the very nature of the condition, from that intervention,” wrote USPSTF.
Arguments for PSA-based screening are not born out by scientific evidence, according to USPSTF, with much uncertainty remaining about whether the test actually reduces mortality rates. Previous studies have shown only statistically insignificant reductions in cancer deaths, with very little effect noticed 10 years post-screening, while the treatments—surgery or radiotherapy—pose the risk of significant harms.
ASTRO acknowledged that PSA screening isn’t a perfect method of detecting prostate cancer, but stated that patients’ lives have been saved by catching the cancer early. Over the last 30 years, there has been a 30 percent decline in death rates associated with prostate cancer due in part to better screening, according to ASTRO.
"The problem with prostate cancer is not finding the cancer but in knowing when to treat and when not to treat," Leonard L. Gunderson, MD, ASTRO chairman, said in a statement. "The USPSTF is correct in addressing the issue of over screening but is wrong to take the option completely off the table."
ASTRO’s position is that the decision to screen should be made between the patient and the physician. It should be tailored around the patient’s medical history and known risk factors, and screening results should be used to discuss all treatment options, which may include watchful waiting.
"Physicians need to be able to provide their patients with the best options for maintaining their health. If PSA screening is the best option, then a physician should be able to decide that," Anthony L. Zietman, MD, ASTRO immediate past chairman, said in the statement.
Prostate cancer is the most commonly diagnosed cancer in men and more than 33,000 men die each year from this disease.