Researchers from the United States and private companies have teamed up to develop a test that can find one cancer cell out of millions of cells in a sample of blood, HealthDay News reported.

If successful, this test would be a breakthrough possibly leading to earlier cancer diagnosis and treatment. What’s more, scientists said the test might also show if a cancer treatment is effective and even predict the best treatment for individuals.

The test relies on circulating tumor cells (CTCs). These cells detach from the main tumor and travel to other parts of the body.

Four years ago, researchers at Massachusetts General Hospital invented a test call CellSearch that could tally CTCs in the body. But scientists couldn’t use this test to grab and examine the cancer cells.

This new test does allow researchers to capture and study those cells. This updated version, which requires a few teaspoons of blood, uses a microchip studded with tens of thousands of tiny posts covered with sticky antibodies (proteins generally found in the blood that detect and destroy invaders, such as bacteria and viruses). As blood passes over the chip, tumor cells cling to the posts.

Scientists believe that the test could replace a biopsy––an invasive and sometimes hazardous procedure––and detect cancer earlier, predict recurrence and assess a patient’s chances of survival.

But experts stressed that this new test is not yet ready for prime time. What’s needed along with the test are new cancer drugs and specific therapies, researchers said, so doctors can best use the CTC information gathered by the test.

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