New blood testing advancements can assist with Alzheimer's, cancer detections

Advances in blood tests aimed at screening for ailments like Alzheimer’s disease and colon cancer can mean faster diagnosis and treatment for patients, said two Allegheny Health Network doctors.

Problems can be found earlier in a way that’s easier on the patient than more invasive cancer screenings, such as a colonoscopy or a Pap smear, said Dr. David Bartlett, chair of AHN Cancer Institute.

“Detecting cancer early, no question, leads to better outcomes,” he said.

Primary care physicians often have conversations with patients about getting cancer screenings, based on their age, and having the option for blood tests might make a patient more willing to follow through, said Dr. Amy Crawford-Faucher, vice chair of the AHN Primary Care Institute.

“I think the convenience is a huge factor. … It’s part of that normal routine and can be done at a doctor’s office,” she said.

There is little known about some of those tests, though, and they can have false positives and negatives, said Dr. Carol Fox, Independence Health System chief medical officer. They shouldn’t replace more traditional screenings and doctor-patient relationships, she said.

“In some instances, these tests are not yet FDA approved, and they may or may not be covered by insurance and, if they are, may not be at the highest level,” she said. “In the future, these types of tests may be game-changers, but it’s much too soon to tell.”

This week, U.S. health regulators approved a first-of-its-kind blood test for colon cancer, according to the Associated Press. The new offering is a noninvasive way for people 45 and older with an average risk to be screened, but it is not a replacement for colonoscopies. The test can detect DNA fragments left behind by tumor cells and precancerous growths, the AP reported.

“A blood test is very easy on the patient,” Bartlett said.

Research released this week indicated that new blood tests could be on the horizon to help doctors diagnose patients with Alzheimer’s disease. The Associated Press reported that the tests aren’t widely used and the U.S. Food and Drug Administration hasn’t formally approved them, but a Swedish study found that a blood test for the disease was more accurate than results from a traditional exam — a spinal tap or brain scan.

A buildup of a protein called beta-amyloid in the brain is a hallmark of the disease that affects a person’s memory, the AP reported. The Alzheimer’s Association is establishing guidelines for doctors who want to order a test and companies developing them plan to seek FDA approval.

Blood tests can provide another option for patients who may be more likely to opt for a familiar method — a blood draw — rather than an invasive or time-consuming screening, Crawford-Faucher said. But the doctor has to be able to be confident in the quality of the test and the accuracy of the results, she said.

The Wall Street Journal reported this week that a growing number of doctors and specialists are turning to two blood tests to help them better identify a patient’s risk for heart disease. The tests look for high levels of specific types of proteins that have been linked to an increased risk for the disease. But they are not universally recommended by U.S. medical organization guidelines, the outlet reported.

In the world of cancer screening, blood tests might be less effective to detect a cancer that is forming than a traditional screening method, Bartlett said. A study on the colon cancer blood test showed that it caught very few of the precancerous growths called polyps that can be found during a colonoscopy, the AP reported.

But there’s no doubt the advances in medicine keep coming to improve the patient experience.

”They’re getting better. That’s the key,” Bartlett said. “Technology is really exploding.”

AHN has been working on research with help of 13,000 blood samples from cancer patients that the health system has collected over the past four years to determine how a patient’s cancer responds during their treatment, he said. That research may ultimately help doctors detect a reemergence of cancer much sooner through a blood test.