Despite rapid advancements in medical technology, some widely publicized breakthroughs may not be as revolutionary as they initially appear, according to one physician. Dr. Mason Pimsler, an internist and medical correspondent, highlights potential limitations in three prominent innovations: blood tests for colorectal cancer screening, at-home Alzheimer's blood tests, and genetic tests for psychiatric medication.
Colorectal cancer, the second-leading cause of cancer-related death in the U.S., is experiencing a significant increase in younger adults. While colonoscopies remain the standard for early detection and prevention, the Shield Blood Test emerged as the first FDA-approved blood test for primary colorectal cancer screening. However, Pimsler notes that the test shows limited detection of Stage 1 colorectal cancer, catching only 55%-65% of cases. It is also less sensitive to precancerous lesions, with the test potentially missing 87% of them. Pimsler emphasizes that a key goal of screening is to identify and remove precancerous polyps, a function the Shield test may not adequately fulfill.
Alzheimer's Disease Biomarker Tests
With Alzheimer's disease projected to affect millions more Americans in the coming decades, at-home or direct-to-consumer blood tests are becoming available. These tests allow individuals to assess biomarkers associated with the disease without an initial specialist visit. However, Pimsler, along with organizations like the Alzheimer's Association, cautions against potential false positives, unclear results, and the emotional distress these tests can cause without proper clinical oversight and counseling. He points out that a positive result does not guarantee a diagnosis and can induce significant anxiety, particularly for those with pre-existing anxiety disorders. Furthermore, unlike some other conditions, identifying Alzheimer's biomarkers through these tests does not currently offer a direct path to disease prevention, treatment, or management on its own.
Genetic Testing for Psychiatric Medication
Finding the right psychiatric medication often involves a trial-and-error process. Tests like GeneSight aim to analyze how a patient's genetic makeup might influence their response to various psychiatric medications. The process involves a cheek swab, with results provided to clinicians in a color-coded report. Pimsler, however, describes such tests as "useless," arguing that they do not eliminate the need for clinical judgment, medical history, and symptom evaluation in prescribing decisions. He contends that these tests do not replace the established process of finding effective treatments and cannot identify a single "cure-all" medication. The U.S. Food and Drug Administration (FDA) has also issued warnings about the potential limitations of psychiatric pharmacogenomic tests, advising careful interpretation.