WASHINGTON, Aug. 18 (UPI) -- Overscreening and overtreatment of disease are detrimental to patients, but researchers are unsure whether changes to screening recommendations for prostate cancer -- which have resulted in far fewer diagnoses -- are missing life-threatening cases of the disease.
Researchers at the American Cancer Society found a steep decline in prostate cancer diagnoses has continued for the last few years since the U.S. Preventive Services Task Force dropped recommendations for routine screening for prostate cancer several years ago, according to a new study published in the journal JAMA Oncology.
In 2011, the USPSTF dropped its suggestion for all men over 50 to have PSA testing for prostate cancer because it found rates of disease diagnosis, treatment and survival were not helped by test absent reason to perform it.
As a result, the percentage of men ages 50 to 74 tested for the disease dropped from 36.8 percent in 2010 to 29.9 percent in 2013 and dropped in men older than 75 from 43.1 percent in 2010 to 36.3 percent in 2013.
In the year following the change, incidence of early-stage prostate cancer dropped by 19 percent from 2011 to 2012. The decline continued the year after, with researchers in the new study finding diagnoses went down by another 6 percent.
Part of the drive toward decreased screening was the overtreatment of early-stage prostate cancer patients who may have benefited from a wait-and-watch method.
Because some cancers are not life-threatening or progress slowly enough that aggressive treatment would cause more overall harm than benefit, many doctors have adopted a "let's see what happens" philosophy seen as overall preferable by patients, doctors and the people who pay for treatment.
Dr. Ahmedin Jemal, a researcher at the American Cancer Society, said previous studies had been contradictory as to whether invasive testing for prostate cancer was saving lives.
Although he said more recent recommendations may be preventing overtreatment, data to show the effects of less routine screening are not yet available, nor are methods of knowing for sure whether a patient's cancer will kill them.
"The nature of prostate cancer is you can find cancer, but it may not be lethal. But we can't tell whether stage 3 cancer would be lethal with current technology," Jemal told UPI in a phone interview. "We need to monitor the later diagnosis and mortality [rates] to see if we're missing cases that need to be caught."
Data may not fully reflect the effect of recent changes to recommendations, but one thing is clear: As low-risk prostate cancer diagnoses have dropped significantly in the last decade -- not just the last few years -- rates of metastatic prostate cancer have skyrocketed since 2004, suggesting somebody is missing something.
The USPSTF is currently reviewing its screening recommendation to find whether mortality has increased with reduced routine screening, the potential benefits and harms of treating more early-stage or screen-detected prostate cancers, and whether the recommendations should be changed again.