The US Food and Drug Administration (FDA) has approved a genetic test that can give women with breast cancer an estimate of whether the disease is likely to return within five to ten years. The MammaPrint test - made by Dutch company Agendia - relies on an intricate computer analysis, which measures the activity of 70 different genes.
Tissue from a surgically removed breast tumour is analysed to establish the activation and suppression patterns of particular genes which are likely to affect recurrence. According to the FDA, similar devices already exist but they usually only measure one or two genes. The results of this new test will provide a 'risk score' that will tell patients if they have a high or low risk of their disease returning in the next decade.
Officials believe that this test will be an important step toward personalising treatment for individual patients. However, they caution that the test is not perfect and is not a substitute for the guidance of a cancer specialist, who tailors a woman's therapy based on factors such as general health, age and tolerance for treatment. They emphasised that doctors and patients should use it in conjunction with other information to decide how aggressively to treat an early tumour.
Steve Gutman, director of FDA's Office of In Vitro Diagnostic Device Evaluation and Safety said that, 'This test is an important step in our journey toward having improved personalised molecular medicine as a tool for use in making better treatment decisions'. He also highlighted that the test is much more accurate at predicting if a woman has a low risk of recurrence. Women at high risk have double the chance of breast cancer returning and spreading than low-risk women. Low risk patients were accurately picked at least 90 per cent of the time. However, just over 20 per cent of the women who were told they were at high risk for a relapse within five years experienced a recurrence.