Medical Minutes
Detecting cancer long before symptoms
There may now be a way to find cancer before symptoms ever occur. A new blood test, which can detect more than 50 types of cancer, has been found to be accurate enough to be rolled out as a multi-cancer screening test among people at higher risk of the disease, including patients age 50 years or older.
In a paper published in the journal Annals of Oncology, researchers report that the test accurately detected cancer, often before any symptoms arose, while having a very low false positive rate. The test also predicted where in the body the cancer is located with a high degree of accuracy, which could help doctors choose effective diagnostic tests.
The California company developing and funding the research is called GRAIL, Inc., and it has now made the multi-cancer early detection test available in the U.S. by prescription only. It is designed to complement other existing screening methods such as those for breast, cervical, prostate, lung and bowel cancers. Many of the cancers that the test is capable of detecting do not have screening tests available, such as liver, pancreatic and esophageal cancers, which are among the most deadly and where early detection could make a real difference.
“Finding cancer early, when treatment is more likely to be successful, is one of the most significant opportunities we have to reduce the burden of cancer. These data suggest that, if used alongside existing screening tests, the multi-cancer detection test could have a profound impact on how cancer is detected and ultimately on public health,” said study investigator Dr. Eric Klein, chairman of the Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland. Ohio.
The test involves taking a sample of blood from each patient and analyzing it for DNA, known as cell-free DNA (cfDNA). Tumors shed it into the blood. Genomic sequencing is used to detect chemical changes to the DNA called “methylation” that control gene expression. Using artificial intelligence (AI), it is now possible to predict where in the body the cancer is located. Results are available within 10 business days from the time the sample reaches the lab.
The third and final sub-study of the Circulating Cell-free Genome Atlas (CCGA) study, which was just completed, investigated the performance of the test in 2,823 people already diagnosed with cancer and 1,254 people without cancer. It detected cancer signals from more than 50 different types of cancer and found that across all four cancer stages (I, II, III, IV), the test correctly identified when cancer was present. The test’s specificity (the true negative rate) was 99.5%, meaning that the test wrongly detected cancer (the false positive rate) in only 0.5% of cases.
“We believe that cancers that shed more cfDNA into the bloodstream are detected more easily,” said Dr. Klein. “These cancers are also more likely to be lethal, and prior research shows that this multi-cancer early detection test more strongly detects these
cancer types. Cancers such as prostate shed less DNA than other tumors, which is why existing screening tests are still important for these cancers.”
Big benefits with 5-minute breathing workout
A new study shows that a breathing exercise known as Inspiratory Muscle Strength Training can reduce blood pressure in weeks, with benefits on par with daily exercise or medication. Working out just five minutes daily via a practice described as “strength training for your breathing muscles” lowers blood pressure and improves some measures of vascular health, according to a new study by researchers at Colorado University at Boulder.
The study, published in the Journal of the American Heart Association, provides the strongest evidence yet that the ultra-time-efficient maneuver known as High-Resistance Inspiratory Muscle Strength Training (IMST) could play a key role in helping aging adults fend off cardiovascular disease. In the United States alone, 65% of adults over age 50 have above-normal blood pressure, putting them at greater risk of heart attack or stroke. Yet, fewer than 40% meet recommended aerobic exercise guidelines.
“There are a lot of lifestyle strategies that we know can help people maintain cardiovascular health as they age. But the reality is, they take a lot of time and effort and can be expensive and hard for some people to access,” said lead author Daniel Craighead, an assistant research professor in the Department of Integrative Physiology. “IMST can be done in five minutes in your own home while you watch TV.”
Developed in the 1980s as a way to help critically ill respiratory disease patients strengthen their diaphragm and other breathing muscles, IMST involves inhaling vigorously through a hand-held device which provides resistance. Imagine sucking hard through a tube that sucks back.
The researchers recruited 36 otherwise healthy adults ages 50 to 79 with above normal systolic blood pressure (120 millimeters of mercury or higher). Half did High-Resistance IMST for six weeks and half did a placebo protocol in which the resistance was much lower. After six weeks, the IMST group saw their systolic blood pressure (the top number) dip nine points on average, a reduction which generally exceeds that achieved by walking 30 minutes a day five days a week. That decline is also equal to the effects of some blood pressure-lowering drug regimens.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
