In the Near Future, Early Cancer Diagnosis Will Be Possible from a Drop of Blood

A genetic test has been developed that detects cancer early with %96 success using a very small blood sample. It is the first test simultaneously providing information on the cancer's organ of origin and causative mutations.

Cancer can be completely treated when diagnosed early. However, failure to identify effective early biomarkers has led to late diagnoses and more deaths. Blood-based tests called liquid biopsies, discussed previously, offer great promise. They include circulating tumor cells, circulating tumor DNA fragments and immune cells in the tumor microenvironment.

- Related topic: The Precursors of Metastasis: Circulating Tumor Cells (CTC), a New Milestone in Cancer Treatment

Plasma, the part of blood excluding red cells, may contain tumor DNA/RNA fragments and tumor-related molecules. Recent research found interactions between immune cells in the tumor microenvironment and tumor cells, producing genetic changes. These include macrophages, platelets and other cells.

Also called thrombocytes and platelets, blood platelets are the second most abundant blood cells. Lacking nuclei, they control bleeding and wound healing. Recent studies found roles in responses to tumor growth. When encountering tumors, they also interact with tumor-related molecules, altering RNA profiles. This “educates” them through tumor cells and makes them help tumor migration to other tissues and organs. These altered cells are called tumor-associated platelets as their designation.

Identifying these mechanisms suggested diagnostic use. Researchers analyzed platelet RNA in tiny blood samples from healthy people and patients with colorectal, brain, pancreatic, liver and biliary, breast and small cell lung cancers. Among 283 participants, there were 228 with localized and metastatic cancers, from whom 55 healthy individuals were distinguished with 96 percent success. The organ of origin was predicted with 71 percent success. Causative mutations were also investigated. Common cancer alterations, MET or ERBB2-positive and mutant KRAS, EGFR or PIK3CA, were detected in RNA analysis.

What Practical Benefits Could This Provide?

A simple blood test could diagnose cancer instead of invasive techniques that burden patients psychologically and anatomically. Liquid biopsies can also identify origin and mutations. Identifying altered pathways may guide targeted therapy and selection of the most appropriate drug.