We have been concerned for years that direct-to-consumer genetic testing of BRCA would be rolled out to the public before studies were completed to determine if the benefits outweigh the risks. Now we're here. This March the FDA began permitting 23andMe to provide women with results for BRCA1 and BRCA2 mutations without consultation with a physician or geneticist. As Vinay Prasad and colleagues argue in a recent JAMA Viewpoint, concerns including that "even assuming a 99.99% sensitivity and specificity of the test, if used by women who are not of Ashkenazi Jewish descent, one in 10 positive results would be false." In addition, these authors worry that women who might have a strong family history but test negative for BRCA might assume that their risk of breast cancer is low and not seek medical advice. These and other concerns lead the writers to conclude that "reliability and reproducibility of a genetic assay are no assurance that a test will improve health outcomes for individual patients."
Overuse of Dialysis in the Elderly
When it comes to elderly patients with advanced kidney disease, it seems that the longer we can delay dialysis the better. Several years ago, the landmark IDEAL trial established that there should be no hard glomerular filtration rate (GFR) threshold for initiating dialysis, but rather that symptoms and intractable electrolyte abnormalities should drive the decision. For elderly patients in particular, the benefits of dialysis seem modest and even hard to establish. Now, an important new analysis in JAMA Internal Medicine affirms our skepticism about aggressive dialysis initiation in the elderly.
In the study, the authors compared mortality between older veterans with advanced kidney disease who received care within the VA system versus those treated in the fee-for-service Medicare system. Not surprisingly, the study showed that patients cared for by Medicare providers received dialysis at a much higher rate -- 82% versus 53% during the study period.
Despite receiving more dialysis, patients within the Medicare system had higher mortality rates after 2 years: 53% versus 44%. As an observational study, the findings are exploratory; nevertheless the association is worrisome. An excellent accompanying editorial calls for greater humility in our approach to dialysis initiation: "The goal should be to encourage thoughtful, joint decision making by nephrologists and their patients. The system should reinforce the careful weighing of pros and cons by supporting healthcare professionals in caring for patients with very low estimated GFR, and financial incentives should be realigned so that we do not inadvertently pressure patients to receive dialysis earlier than would be best for them."
It might seem intuitive that screening for peripheral artery disease (PAD) would be a good idea. Screening with ankle-brachial index is noninvasive and PAD might lead to serious morbidity when it remains undetected. But there also may be downsides to screening, such as unnecessary treatments. This question was addressed recently by the U.S. Preventive Services Task Force, and in its most recent recommendations the task force found insufficient evidence to recommend screening for PAD with ankle-brachial index, mainly because the authors found little evidence that treating asymptomatic PAD improves outcomes.
As the JAMA editorialist concludes, a careful history is the key to screening for PAD. Attention should be focused on identifying symptoms suggestive of ischemia in older people for whom ankle-brachial index then becomes an appropriate diagnostic study.
Colon Cancer Surveillance
We were happy to see this recent trial in JAMA comparing two approaches to surveillance for patients with stage II or III colorectal cancer. In the first, patients received CT and CEA measurements at 6, 12, 18, 24, and 36 months after surgery; in the second, testing was only completed at 12 and 36 months. Not surprisingly (to us at least), the more frequent surveillance failed to impact 5-year outcomes. We are concerned that surveillance for patients who are in cancer remission has become excessive, leading to waste and potential harms for patients. We welcome further studies that rigorously test whether aggressive cancer surveillance programs provide benefit.
"Updates in Slow Medicine" applies the latest medical research to support a thoughtful approach to clinical care. It is produced by Pieter Cohen, MD, of Harvard Medical School, and Michael Hochman, MD, MPH, of the Keck School of Medicine at the University of Southern California. To learn more, visit the Updates in Slow Medicine website.
https://www.medpagetoday.com/blogs/slowmedicine/75094
