WASHINGTON -- A biotech company today will begin offering the first genetic test to assess a woman's risk for the most common forms of breast cancer, reigniting debate about the growing number of unregulated genetic tests.

The test by deCODE genetics of Reykjavik, Iceland, a respected pioneer in genetic research, promises to determine a woman's risk through a simple blood sample or cheek swab. Previously, the only tests for breast cancer risk were for relatively rare genes -- leaving most women with no way to assess their individual genetic predisposition.

"What this does for women is allow them to assess their personal risk for the common forms of breast cancer," said Kari Stefansson, deCODE's chief executive. "That's what you need to do to make early diagnoses or take preventive measures. This test will most definitely save lives."

While welcomed by some patient advocates and doctors, the $1,625 test raises concerns among others. Some questioned its reliability, while others worried that the results could either lull women into a false sense of complacency or needlessly alarm them, prompting them to take unnecessary tests or even undergo unneeded surgery.

"There is at least a significant chance this test could falsely reassure some women and alarm others," said Dr. Eric Winer, a breast cancer expert at Harvard Medical School and spokesman for the American Society of Clinical Oncology.