Common Cancer Screenings May Not Extend Life Longevity

TUESDAY, Aug. 29, 2023 (HealthDay News) -- Cancer screening may not actually extend lives, with the possible exception of colorectal cancer screening with sigmoidoscopy, according to a review published online Aug. 28 in JAMA Internal Medicine.

Michael Bretthauer, M.D., Ph.D., from University of Oslo in Norway, and colleagues conducted a review and meta-analysis of 18 clinical trials with more than nine years of follow-up reporting all-cause mortality and estimated lifetime gains from six commonly used cancer screening tests versus no screening. Screening tests of interest included mammography for breast cancer; colonoscopy, sigmoidoscopy, or fecal occult blood testing (FOBT) for colorectal cancer; computed tomography screening for lung cancer in smokers and former smokers; and prostate-specific antigen testing for prostate cancer.

Based on trial data from more than 2.1 million trial participants, the researchers found that the only screening test with a significant lifetime gain was sigmoidoscopy (110 days). There were no significant differences in length of life following mammography and FOBT screening every year or every other year. For prostate cancer screening and lung cancer screening, estimates of prolonged life were uncertain. Estimates of prolonged life for colonoscopy for colorectal cancer (37 days) were also uncertain based on the data.

“Screening tests with a positive benefit-harm balance measured in incidence and mortality of the target cancer compared with harms and burden may well be worthwhile,” the authors write. "Even larger trials may be needed to tease out any association of cancer screening with longevity with more precise effect estimates."

The authors note study limitations such as the follow-up time period and number of patients in the trials.

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