Why Test Blood for Cancer

When we think of the different methods doctors use to diagnose cancer, we commonly think about X-rays and tissue biopsies, not blood tests. However, according to the Mayo Clinic, blood tests can detect certain cancers of the blood and identify tumor markers that serve as warning signs that cancer may be present.

Leukemia

• Leukemia is a cancer marked by the proliferation of abnormal white blood cells. A complete blood count will show the presence of these cells.

Multiple Myeloma

• Multiple myeloma is a cancer that forms in blood plasma cells. A blood test can help diagnose this cancer because the disease causes increased proteins in the blood and may also cause a decrease in white blood cells and platelets.

Tumor Markers

• Tumor cells produce chemicals called tumor markers, and blood tests can detect the presence of these substances.

Cautions

• Tumor markers can be present in benign growths, and some normal cells also contain tumor markers.

Considerations

• The Mayo Clinic cautions that blood tests are just one diagnostic tool. An oncologist will likely conduct other tests to confirm or dismiss a cancer diagnosis.