Cancer screening smackdown continues: Pap smears and colonoscopies take a hit

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It’s been a long three weeks for the American Cancer Society. The public relations nightmare that started with an admission to the New York Times that they’d overstated the benefits of detecting many cancers is continuing with new evidence that two of the most reliable screenings—Pap smears for cervical cancer and colonoscopies for colon cancer—have some serious hiccups of their own.

The brouhaha began in earnest late last month when the New York Times ran a lengthy piece about how and why the American Cancer Society (ACS) decided to backpedal on its language regarding the benefits of breast and prostate cancer screenings. With these two diseases accounting for 26% of all cancers in the U.S., it’s no surprise that the story ignited a media firestorm, including a little flare of our own.

The conflagration’s initial spark was an analysis in that week’s Journal of the American Medical Association in which the authors outlined some serious flaws in the system for breast and prostate cancer screening and called for new approaches. “Screening has value, but we need to understand what it can and cannot do,” said Laura Esserman, MD, a breast cancer surgeon at the University of California San Francisco Medical Center and the study’s lead author. “Part of the problem is that we’ve been too worried about keeping the message simple.”

Later that week, the American Cancer Society’s CEO posted a message on the organization’s web site. Attempting, no doubt, to quell the public’s concerns and ease confusion about the benefits of cancer screenings he wrote:

“We encourage women at average risk to get mammograms at age 40, to get Pap tests as soon as they are sexually active or no later than age 21, and both men and women at average risk to get screened for colon cancer starting at age 50.”

But that kind of pat answer sounds suspiciously like the kind of overly simplistic messaging Esserman was rallying against, and the New York Times wasn’t about to leave it alone. Instead, Denise Grady tackled the mammogram murkiness head on. She spoke with a handful of leading breast cancer experts, many of whom agreed “that, despite the cancer society’s guidelines, evidence was lacking for a benefit in screening women from 40 to 50.”

Then the ACS took another hit this week when Pap smears were hauled into the ring. Screening practices for cervical cancer were questioned when a new study, appearing in the Annals of Internal Medicine, found that doctors perform many unnecessarily, ignoring guidelines from leading cancer organizations, such as the ACS.

And in a final blow to the public’s cancer-screening confidence, yet another headline-making study revealed a weak link in preventing colon cancer. The problem isn’t in the accuracy of the screening but in the reliability of the professional on the other end of the endoscope.

The study, published in this month’s issue of the journal Clinical Gastroenterology and Hepatology, shows the effectiveness of colonoscopy, a means to detect and prevent colon cancer, depends on the time of day that it’s done.

Researchers at the University of California, Los Angeles, looked at 477 patients undergoing routine colonoscopies and found that early-morning procedures yielded 27% more polyps per patient than later cases. They also noted that the number of polyps found decreased hour-by-hour as the day progressed.

The authors do mention that early-morning bowel preps tend to be better (ie: more complete) than those done later, which may skew the final outcome. But they put much more emphasis on their hypothesis that “provider fatigue” is behind the discrepancy, meaning that endoscopists get tired as the day wears on and end up missing more polyps. The authors blame the repetitive and prolonged nature of the job, comparing it to other professions with similar fatigue issues, such as truck driving and air traffic control.

“Although individual patient risk is very low, multiplying this effect by thousands of patients across the U.S. could mean we’re missing lots of polyps, some of which might turn into cancer,” says Brennan Spiegel, MD, a digestive disease expert and one of the study’s authors.

That’s no small hitch considering that polyp removal is associated with an up to 90% reduction in colon cancer, the country’s second-leading cause of cancer deaths.

No doubt, the ACS will be doing damage control for quite some time. Meanwhile, Americans can enjoy a fleeting moment of frankness in Esserman’s summation of the current state of cancer-screening affairs: “We’ve done some good; we’ve done some harm; and we need to make screening better.”

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