Philip Greenspun’s Weblog

Let’s see how the War on Cancer that Richard Nixon started is going… “In gold-standard trial, invitation to colonoscopy reduced cancer incidence but not death” (STAT):

For decades, gastroenterologists put colonoscopies on a pedestal. If everyone would get the screening just once a decade, clinicians believed it could practically make colorectal cancer “extinct,” said Michael Bretthauer, a gastroenterologist and researcher in Norway. But new results from a clinical trial that he led throw confidence in colonoscopy’s dominance into doubt.

The trial’s primary analysis found that colonoscopy only cut colon cancer risk by roughly a fifth, far below past estimates of the test’s efficacy, and didn’t provide any significant reduction in colon cancer mortality. Gastroenterologists, including Bretthauer, reacted to the trial’s results with a mixture of shock, disappointment, and even some mild disbelief.

… So Bretthauer, of the University of Oslo and Oslo University Hospital, and several colleagues started one a decade ago, recruiting more than 80,000 people aged 55 to 64 in Poland, Norway, and Sweden to test if colonoscopy was truly as good as they all believed. Roughly 28,000 of the participants were randomly selected to receive an invitation to get a colonoscopy, and the rest went about their usual care, which did not include regular colonoscopy screening.

The researchers then kept track of colonoscopies, colon cancer diagnoses, colon cancer deaths, and deaths from any cause. After 10 years, the researchers found that the participants who were invited to colonoscopy had an 18% reduction in colon cancer risk but were no less likely to die from colon cancer than those who were never invited to screening.

Five colonoscopies will cost our society (private insurance or Medicaid/Medicare) about the same as 5 cruise vacations. Is it still worth getting 5 colonoscopies before finally dying (maybe of colon cancer)? Wouldn’t we be better off if we invested these resources in something enjoyable? “Pfizer CEO Albert Bourla tests positive for Covid-19 again” (CNN) can inspire us. His reported COVID-19 symptoms were exactly what same-age rednecks who never got any shots or pills reported. However, unlike the rednecks, he followed the Science and, pumped full of multiple “vaccine” shots and an experimental pill, went through COVID-19 in a state of grace.

Now colon cancer screening can go through the same statistical mill as breast cancer screening via annual mammograms. Here in the U.S. we convinced ourselves that annual X-rays were helpful. Then we realized that the improved 5-year survival rates for breast cancer were primarily due to treating “patients with breasts” (formerly known as “women”) for cancer when they didn’t have cancer. Since these victims of overdiagnosis never had cancer to begin with, they were unlikely to have died of cancer 5 years later. “Benefits and Risks of Mammography Screening in Women Ages 40 to 49 Years” is a 2022 article explaining the settled Science:

The American College of Obstetricians and Gynecologists (ACOG), American College of Radiology (ACR), American Cancer Society (ACS), National Comprehensive Cancer Care Network, and U.S Preventative Services Task Force (USPSTF) all reach different conclusions about when and how often to recommend screening mammography. Each organization places different relative weights on the benefits and risks of screening and uses different standards for evidence.