When Gene Tests for Breast Cancer Reveal Grim Data but No Guidance; New York Times, 3/11/16

Gina Kolata, New York Times; When Gene Tests for Breast Cancer Reveal Grim Data but No Guidance:

"Ms. Watts’s experience highlights an unsettling side to the growing use of genetics in medicine, particularly breast cancer care. Doctors have long been tantalized by a future in which powerful methods of genetic testing would allow treatments to be tailored to a patient’s genetic makeup. Today, in breast cancer treatment, testing of tumors and healthy cells to look for mutations has become standard.

But as Ms. Watts found out, “our ability to sequence genes has gotten ahead of our ability to know what it means,” said Eric P. Winer, the director of the breast oncology program at Harvard’s Dana-Farber Cancer Institute.

The ambiguities and disappointments play out in two areas: There is genetic testing of patients to see if they inherited mutations that predisposed them to cancer, and there is genetic testing of cells from the cancer to look for mutations that drive the tumor’s growth — but if found often cannot be targeted by any drug on the market.

The ability to understand and interpret genetic tests will surely improve. But for now, what sounds like a simple test can leave patients with frightening information but no clear options or guidance for treatment decisions.

“The stakes are very high,” said Dr. Evans, the geneticist who counseled Ms. Watts. “You have inherently nuanced and confusing tests and widespread ordering and interpretation by doctors who aren’t really equipped to do so,” he said. “The situation is ripe for overinterpretation and misinterpretation.”"