Blood Test May Revolutionize Cancer Treatment and Diagnosis

Scientists are looking at a blood test that could discover a single cancer cell floating amid billions of normal blood cells.

In 2007, researchers at Massachusetts General Hospital, developed a "microfluidic chip," called CellSearch, which could count the number of stray cancer cells, but that test didn't allow scientists to trap whole cells and analyze them.

But on Monday, Mass General announced an agreement with Veridex LLC, part of Johnson & Johnson, to study a newer version of the test. According to the Associated Press, the updated test requires only a couple of teaspoons of blood.

The microchip is dotted with tens of thousands of tiny posts covered with antibodies designed to stick to tumor cells. As blood passes over the chip, tumor cells separate from the pack and adhere to the posts.

Scientists are wagering that this type of test, if successful, might also detect cancer early in its course, predict the odds for a recurrence, and assess a patient's general prognosis.

"There has been speculation that these [stray] cells are the ones that are responsible for the spreading of the disease," noted one expert, Dr. Massimo Cristofanilli, professor and chairman of medical oncology at Fox Chase Cancer Center in Philadelphia. "Simple enumeration tells us that this patient has a worse prognosis . . . Now the question is, what other information we can gather, if we are able to capture these cells? For example, could we do gene analysis profiling and can we get information for the best treatment?"

As it stands today, biopsy -- an invasive and sometimes even hazardous procedure -- is one of the few ways doctors can get key information about a cancer's size and characteristics.

"Many people consider [the new blood test to be] a 'liquid biopsy,' so that eventually we can access cancer cells that are representative of the tumor without performing an invasive biopsy," said Cristofanilli, who is not involved in developing the test.

Experts stressed that the new type of test, if it ever arises, may still be years away, and researchers still aren't sure what these circulating tumor cells (CTCs) actually mean.

Identifying cancers at an early stage increases survivability and increases the range of treatment options.

Indeed, this has the potential to revolutionize pancreatic cancer and other difficult cancers. For now, the test is not being used in clinical situations, but several major cancer centers around the country are studying the test.