Lower rates of prostate cancer screening are associated with more advanced forms of the cancer

Author: Nancy Lapid

(Reuters) – A decline in prostate cancer screening is linked to a subsequent increase in advanced cancers, according to the U.S. Department of Veterans Affairs (VA), findings that could prompt a rethink of current U.S. testing guidelines.

The new study, which included more than 5 million men over the age of 40 at 128 VA facilities nationwide between 2005 and 2019, found that when screening was encouraged, later diagnosis of incurable advanced malignancies was less likely.

“Screening rates were significant predictors of metastatic cancer rates,” study leader Dr. Brent Rose of the University of California, San Diego said at a press conference Monday at the American Society for Radiation Oncology (ASTRO) annual meeting in San Antonio, Texas. Metastatic cancers are those that have advanced and spread to other parts of the body.

The benefits of prostate cancer screening have been controversial. In 2012, the US Preventive Services Task Force (USPSTF) advised against it, arguing that because the disease usually progresses very slowly, the risks of screening outweigh the potential benefits. There was concern that suspicion of prostate cancer based on a common blood test could lead to painful, potentially risky biopsies that may not have been necessary.

In 2018, based on new evidence, the panel changed its recommendation to limit prostate cancer screening to men aged 55 to 69, and only if they “express a preference for screening after being informed and understanding the benefits and risks.”

Overall at VA facilities, screening rates with blood tests for prostate-specific antigen (PSA) levels fell from 47.2% in 2005 to 37.0% in 2019, the researchers reported.

During that period, rates of metastatic prostate cancer rose from 5.2 per 100,000 men to 7.9 per 100,000, with the increase driven by increases in the 55-to-69 age groups and those over 70, the researchers said.

In some institutions, higher screening rates were associated with lower rates of subsequent diagnoses of advanced cancers. But for every 10% reduction in screening, there was a corresponding 10% increase in the incidence of metastatic prostate cancer five years later, the researchers said.

Observational studies like this cannot prove cause and effect, and earlier randomized trials comparing screening with no screening have produced conflicting results, further complicating the issue. A large European trial showed significant benefit, but a North American trial did not.

In the North American trial, however, many of the men assigned to the no-screening group were “secretly” seen privately by their personal physicians, which likely influenced the results, said ASTRO President-elect Dr. Jeff Michalski of the University of Washington School of Medicine. in St. Louis, he said at the press conference.

Rose noted that while the USPSTF’s advice to limit prostate cancer screening has resulted in lower rates of prostate cancer diagnoses, rates of metastatic prostate cancer have increased “more dramatically.”

“We hope this data will give the USPSTF an opportunity to reevaluate its recommendations,” Michalski said.

A USPSTF spokesperson said there is currently no update to prostate cancer screening recommendations.

(Reporting by Nancy Lapid; Editing by Michele Gershberg and Bill Berkrot)