As a cancer survivor with a strong family history of cancer, I have been following the development progress of blood tests for cancer for years. Until recently, the only blood test available for breast cancer was CA-125, which is only useful for detecting recurrence and even then isn’t really very accurate.
There have been no physical tests for early Alzheimer’s Disease (AD) or Parkinson’s Disease (PD). Recently, a test for PD was announced – detection of alpha-synuclein in spinal fluid. That’s better than nothing but far more invasive than a blood test.
By Laura Landro, The Wall Street Journal, April 19, 2023
Using a single blood sample, one test released last year can detect early signals for more than 50 types of cancer, including some such as pancreatic cancer for which no routine preventive screening assays have existed up to this point. Other blood tests are proving accurate in detecting amyloid plaques—the proteins that clump together in the brains of Alzheimer’s patients, leading to eventual loss of memory and thinking skills—even before cognitive declines have been experienced…
Grail Inc., a Menlo Park, Calif., biotech company, has produced a $949 cancer test called Galleri, intended for patients at higher risk for cancer, including those over the age of 50 or those with other risks such as smoking, obesity or a family history of cancer. It uses DNA sequencing and machine-learning technology to analyze DNA shed by cancer cells in the bloodstream.
In addition to determining whether a cancer signal is present, Galleri includes predictions of where the signal most likely is coming from in the body. Although it detects a positive signal in only 1.1% of tests, about 4 in 10 patients with a positive cancer-signal result are expected to have a confirmed cancer diagnosis, according to study data. There are caveats: If no cancer is confirmed with further testing, it could mean the test was insufficient to detect it, including cancer that is not shedding DNA into the bloodstream. And false positive and false negative results do occur, as in most cancer testing…
The new Alzheimer’s blood tests, meanwhile, are meant to help determine if memory loss and brain aging are due to early stages of the disease. These tests, available with a doctor’s prescription, include one from lab giant Quest Diagnostics Inc. and one developed at Washington University School of Medicine in St. Louis and licensed to C2N Diagnostics… At $500 to $1,250, blood tests for Alzheimer’s disease aren’t covered by most health insurance… [end quote]
Since obesity is a risk factor for both cancer and Alzheimer’s Disease the potential customer pool for these tests is immense.
Detecting cancer early can be life-saving. Detecting AD early can potentially qualify a patient for one of the clinical trials of drugs to slow the progress of the disease.
Since insurance doesn’t reimburse for these tests they will be used primarily by those who can afford them. For example, any senior citizen who has a family history of cancer, such as my older brother, @OrmontUS.
If the tests get approved for reimbursement by Medicare they would have Macroeconomic significance since the cost would run into the billions of dollars.