Test could lead to better cancer treatment

By Stephen Smith, Globe Staff

Boston researchers have developed a test that can identify minute amounts of tumor cells floating in the blood of cancer patients, a discovery that could lead to better treatments with fewer side effects.

The technology invented at Massachusetts General Hospital uses a microchip scanner no bigger than a business card to analyze a patient's blood, hunting for stray cells shed by tumors. The device is so powerful that it can sniff out a single cancer cell among 1 billion healthy blood cells.

Once those cells are captured, their genetic fingerprints can help determine the most effective drug for a patient whose cancer has already begun spreading, and also show whether medication has lost its effectiveness. Now, the technology is used in patients whose cancer has already spread, but scientists hope in the future the chip will be able to detect cancer's spread before secondary tumors have become established.

Although the device is not yet ready for widespread use, a report posted online today in the New England Journal of Medicine showed that it successfully identified migrating cancer cells in lung cancer patients and spotted important genetic quirks in those cells.

Scientists not involved with the research said the innovation represents a significant improvement on existing cancer blood tests and predicted that it could revolutionize treatment, especially for lung cancer, which kills more Americans than any other cancer.

Mass. General's approach brings together two of the hottest fields in cancer research: the incredibly tiny devices of nanotechnology, and personalized medicine, the promise of tailoring treatments to individual patients.

"To me, as a scientist, this is huge," said Dr. Shakun Malik, director of the lung cancer program at Georgetown University's Lombardi Comprehensive Cancer Center in Washington, DC. "To be able to just do a blood test, that opens a whole new, wide world. It will give us a lead time to find out if the patient has stopped responding to treatment."