From an August 28, 2023 article in MedPage:

A series of articles published in JAMA Internal Medicine have taken on the question of whether cancer screening actually saves lives.

A systematic review and meta-analysisopens in a new tab or window involving more than 2 million patients showed that with the possible exception of colorectal cancer screening with sigmoidoscopy, the “current evidence does not substantiate the claim that common cancer screening tests save lives by extending lifetime,” reported Michael Bretthauer, MD, PhD, of the University of Oslo in Norway, and colleagues.

Their study, which included 18 long-term randomized clinical trials, indicated that sigmoidoscopy was the only screening test with a significant lifetime gain (110 days, 95% CI 0-274).

There was no significant difference following:

• Mammography (0 days, 95% CI -190 to 237)
• Prostate-specific antigen (PSA) testing for prostate cancer (37 days, 95% CI -37 to 73)
• Colonoscopy (37 days, 95% CI -146 to 146)
• Fecal occult blood testing (FOBT) every year or every other year (0 days, 95% CI -70.7 to 70.7)
• CT lung cancer screening (107 days, 95% CI -286 days to 430)

Bretthauer and colleagues noted that while they may not have observed longer lives with five of the six screening tests, that does not mean that some individuals don’t prolong their lives with screening.

“Without screening, these patients may have died of cancer because it would have been detected at a later, incurable stage,” they wrote. “Thus, these patients experience a gain in lifetime.”

However, they added that other individuals experience a lifetime loss due to the harms associated with screening or treatments from screening-detected cancers, such as colon perforation during colonoscopy or myocardial infarction following radical prostatectomy.

In a simultaneously published Viewpoint, Bretthauer and two colleagues suggested that despite concerns about overdiagnosis and harms of screening, it is “difficult, or indeed impossible” to phase screening programs out, “even when research has failed to document significant benefits,” and discussions about the balance of harms and benefits associated with screening “have become a threat to powerful stakeholders.”

“Cancer screening guidelines are often developed by screening professionals, screening organizations, and patient representatives, with their vested interests,” they pointed out. “We propose that screening guidelines should not allow individuals or organizations with clinical, financial, or intellectual interests in leading roles of guideline development. This would improve quality and trustworthiness of recommendations.”