National Cancer Institute
Science Behind the News Understanding Cancer
A drawing of a patient having blood drawn by a technician using a hypodermic needle.

Blood Tests

Many cancers cannot yet be readily detected in their early stages, but scientists are working hard to find new clues. Scientists are trying to develop blood tests that might alert people to such cancers while they are still in their early stages. For example, several blood tests for ovarian or prostate cancer are under active study.

One example is a substance called prostate-specific antigen (PSA), produced by cells of the prostate gland. PSA circulates in the blood and can be detected and measured with a simple blood test.

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