Test may help predict breast cancer return

U.S. health officials approved a genetic test last week that can give women with early breast cancer an estimate of whether the disease is likely to return in five to 10 years.

Officials cautioned, however, that the test was not perfect and should be used with other information to help doctors and patients decide how aggressively to treat an early tumor.

Called MammaPrint and made by the Dutch company Agendia, the test is the first with U.S. Food and Drug Administration approval that relies on a complicated computer analysis of several genes. Cancer recurrence depends partly on the activation and suppression of certain genes in a tumor.

The test measures the activity of 70 genes using a sample from a breast cancer tumor that has been removed. Women will be told if they have a high or low risk of their disease returning in five to 10 years.

Women at high risk have about twice the chance of breast cancer returning and spreading than low-risk women.

The test accurately picked which women were at low risk at least 90% of the time, FDA officials said. But for women who were told they were at high risk for a recurrence within five years, just 23% had their cancer come back.

Doctors and patients should use the findings with other information to choose a course of therapy, FDA officials said.