In April 2014, Personal Genome Diagnostics (PGDx) launched a new test to detect and treat cancerous tumors. PGDx was founded by Luis Diaz, MD, and Victor Velculescu, MD, PhD, both internationally recognized leaders in cancer genomics at Johns Hopkins University. PGDx has been funded primarily through revenues from the cancer genome analysis services it provides, but has now financed additional funds from private investors. This new source of income will allow further development and marketing of circulating tumor DNA tests through MEDDETECTTM Assay.
How do these tests work? All tumors, including those in the lungs, have microscopic fragments that break off and are released into the circulatory system. By analyzing these, researchers can identify the DNA makeup of a tumor.
In an interview with Diane Rehm on her NPR broadcast show, “The Diane Rehm Show,” Dr. Diaz stated that mutations caused by tumors can be precisely detected through testing of plasma containing these tumor fragments. Eventually this can lead to development of specific treatments to combat the tumor. (Transcript of Interview)
Most tests are currently on patients with an advanced stage of cancer, but early results lead researchers to believe these tests will eventually lead to early diagnosis and the ability to directly and uniquely attack the tumor with its specific makeup.
Tumor “fingerprints” in the blood A variety of tumors from throughout the body can be detected, including those in lung cancer, colorectal, gastric, brain, as well as head and neck cancer. Also on the interview with Ms. Rehm was Dr. Ash Alizadeh, assistant professor of medicine at Stanford School of Medicine. Dr. Alizadeh shared that though cancers are similar to each other, scientists can distinguish cancer in a lung versus cancer in the brain, for example, by analyzing the type of mutations found. However this classification needs further development. So far lung cancer, with its particular genetic alterations, is the most studied type of cancer.
Pros and cons of early testing While early detection is an exciting prospect for more successful treatments in the future, there may be a downside until further research is performed. Not all cancers are lethal; in fact, some may reside in a person until their death with no ill effects. If every cancer found is treated with the potential side effects, there may be unnecessary harm to the patient.
Dr. Diaz posed the question, “Which cancers are lethal and which cancers can you treat less aggressively?” Or which should not be treated at all? Those are still unanswered questions, but these new tests are a step in the right direction for the early detection and treatment of lung and other lethal cancers.