A new blood test may help predict whether breast cancer will return

A blood test or liquid biopsies taken five years after breast cancer treatment may help identify women who were more likely to relapse, a preliminary study has found.

fitness Updated: Dec 09, 2017 11:08 IST
Associated Press
Blood test,Cancer,Breast cancer
A negative result means a 98% chance that you would not have a recurrence in the next two years and could skip further treatment.(Shutterstock)

A blood test taken five years after breast cancer treatment helped identify women who were more likely to relapse, long before a lump or other signs appeared, a preliminary study has found. It was the largest experiment so far to use these tests, called liquid biopsies. Results suggest they may reveal which women need longer preventive therapy and which ones can be spared it. A previous device used estimated specific protein makers present in the woman’s blood sample to screen breast cancer in 15 minutes.

“It could provide an early warning for some women that cancer is returning,” said Dr Joseph Sparano of Montefiore Einstein Center for Cancer Care in New York. “If you had a negative test, there was a 98% chance you would not have a recurrence in the next two years and perhaps could skip further treatment,” he added.

Sparano led the study and shared the results on Friday at the San Antonio Breast Cancer Symposium. The test — CellSearch — looks for stray cancer cells in the blood.Breast cancer survivors may be tempted to rush out and get it, but doctors say it’s too soon for that. Although it’s been used for about a decade to monitor certain patients with advanced cancer during treatment, its value for helping to predict breast cancer relapse risk is not well established.

The test looks for stray cancer cells in the blood. (Shutterstock)

The new study should spur research on this right away, said Dr Massimo Cristofanilli, a breast cancer specialist at Northwestern University in Chicago, who has used these tests and consults for another company developing one.

The study involved 547 women in long-term follow-up from an earlier cancer drug study. Two-thirds of them had cancers fuelled by estrogen, and in most cases it had spread to the lymph nodes but not more widely. All had surgery and chemotherapy followed by hormone-blocking medicines for five years. Guidelines now recommend considering hormone blockers for up to 10 years, but they have side effects and their benefit beyond five years is fairly small.

Women in the study had a CellSearch test five years on average after their cancer was found and treated.Among those with estrogen-fueled disease, 5% had cancer cells in the blood test, and they turned out to have a 22-fold higher risk of recurrence within roughly two years compared to women whose blood test was negative.

About 65% of women with hormone-positive disease and a positive blood test did not have a new diagnosis of breast cancer within two years. But that doesn’t mean the blood test gave a false alarm, Sparano said. “We haven’t followed the patients long enough. It could be that more tumors become evident with more time,” he said.

The blood test seemed to do a good job of identifying which of these hormone-positive patients were at low risk of recurrence, suggesting that women who test negative may be able to forgo an additional five years of hormone-blocking medicines.The test did not predict recurrence risk in the rest of the women, whose tumours were not fuelled by estrogen and who have a lower risk of recurrence after five years.

The study was funded by the Breast Cancer Research Foundation, Susan G. Komen Foundation and the National Cancer Institute.

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First Published: Dec 09, 2017 11:06 IST