FRIDAY, Oct. 28, 2022 (HealthDay News) — A large new study of U.S. veterans shows that as prostate cancer screening rates decline, the number of men diagnosed with advanced-stage cancer is rising.

The researchers found that at 128 US Veterans Affairs Medical Centers, PSA screening rates for prostate cancer declined between 2008 and 2019, the period when guidelines came in to recommend against routine screening.

But patterns varied among individual centers, with some remaining high screening rates.

And in subsequent years, the study found, a trend emerged: VA centers with higher rates of PSA screening had fewer cases metastatic prostate cancerwhile more cases are diagnosed in centers with lower levels of screening.

Metastatic refers to prostate cancer that has spread to distant places in the body and cannot be cured.

Experts said the results do not mean that all men at average risk of prostate cancer should be screened regularly for the disease.

But the results add to a long-standing debate on the issue.

Prostate cancer is very common: According to the American Cancer Society, about 1 in 8 men will be diagnosed with the disease in their lifetime. But the cancer is often slow-growing and may never progress to a life-threatening point: about 1 in 41 men actually die from the disease.

That is why planned screening — p blood tests which measure a protein called PSA – have been controversial. The main concern is that it can often detect small tumors that would never become harmful – leading to “overtreatment” that puts men at risk of side effects such as incontinence and erectile dysfunction.

In addition, two major studies published about a decade ago came to conflicting conclusions about the value of screening. One in the US found that annual PSA screening did not reduce men’s risk of being diagnosed with metastatic prostate cancer or dying from the disease.

Another study conducted in Europe found that screening does reduce the diagnosis of cancer at advanced stages.

In 2012, the US Preventive Services Task Force (USPSTF) recommended against routine PSA screening for men at average risk.

Studies since then have shown an increase in metastatic prostate cancer among American men. But it’s not yet clear whether lower PSA screening rates and missed chances of catching early-stage cancer are to blame.

According to lead researcher Dr. Alex Bryant, the new findings suggest that declining screening rates are part of the story.

“I think the recent increase in metastatic prostate cancer is probably related to the historic decline in PSA screening,” said Bryant, a radiation oncologist at the University of Michigan Rogel Cancer Center in Ann Arbor.

But, he added, this is “hardly the full story.”

According to the researchers, the magnitude of the increase in the number of metastatic cancers does not appear to be explained only by the change in PSA screening. It’s unclear what other explanations might be, Bryant said.

The findings were published on October 24 JAMA Oncology and presented Tuesday at the American Society of Radiation Oncology meeting in San Antonio.

The study found that between 2005 and 2019, PSA screening rates at VA centers dropped from about 47% to 37% — the proportion of men age 40 and older who were screened in that year.

Meanwhile, the rate of metastatic prostate cancer has risen from about 5 per 100,000 men in 2005 to nearly 8 per 100,000 in 2019. Comparing medical centers, the researchers found that those that maintained higher screening rates had fewer advanced cancers: for every 10% increase in screening rates, the rate of metastatic cancer decreased by 9%.

Experts who were not involved in the study were divided on whether this information is useful for individual men.

Dr. Anthony Corcoran, who directs urologic oncology at NYU Langone Hospital on Long Island, said yes.

In 2018, the USPSTF updated its guidelines again, saying that for men ages 55 to 69, the decision to get PSA screening should be made on an individual basis after discussing the pros and cons with a doctor.

Corcoran said the new findings are further evidence that screening reduces the chances of diagnosing metastatic cancer. But, he said, that still needs to be balanced against the downsides of screening for any individual.

Age itself shouldn’t be the deciding factor, Corcoran said. A 70-year-old man in good health may have many years of life ahead of him and benefit from PSA screening; A 70-year-old man in poor health cannot.

“The decision to screen should be based on the patient’s overall health and what they value,” Corcoran said.

Dr. Robert Dreiser, associate director of the University of Virginia Cancer Center in Charlottesville, did not see the findings as helpful for individual decision-making.

“The data here are interesting and provocative,” said Dreiser, who is also a fellow with the American Society of Clinical Oncology. But, he added, they only show a relationship between facility-level PSA screening rates and metastatic cancer — not evidence that screening will protect men from developing early-stage cancer.

However, all three physicians agreed that these individual discussions are key to making screening decisions.

Dreiser said it’s important for men to understand their baseline risk for prostate cancer, as those at increased risk will benefit more from screening.

This group includes black men and men whose father or brother developed prostate cancer before the age of 65. The American Cancer Society recommends that they talk to their doctor about PSA screening starting at age 45. This discussion should occur earlier — at age 40 — if a man has more than one first-degree relative who developed prostate cancer at an early age.

Additional information

The American Cancer Society has more information prostate cancer screening.

SOURCES: Alex Bryant, MD, radiation oncologist, Michigan Rogel Cancer Center, Ann Arbor; Anthony Corcoran, MD, Associate Professor, Department of Urology, NYU Long Island School of Medicine, Director, Division of Urologic Oncology, NYU Langone Hospital – Long Island, Garden City, NY; Robert Dreiser, MD, associate director, University of Virginia Cancer Center, Charlottesville, and volunteer expert, American Society of Clinical Oncology, Alexandria, VA; JAMA Oncology, 24 October 2022, online; American Society of Radiation Oncology Meeting, October 25, 2022, San Antonio