Suppressing ovary function curbs breast cancer recurrence

MUMBAI: A multi-centre study has found that suppressing ovary function and administering cancer-preventive drug tamoxifen can curb recurrence of breast cancer among young women more effectively than tamoxifen treatment alone. Experts say the findings not only offer hope of arresting high-risk and aggressive breast cancer but may also chart a new treatment course.

In the ongoing study conducted by the International Breast Cancer Study Group (IBSCG) with 3,000 women, it was found that tamoxifen treatment and ovarian suppression function (OSF) reduced the chances of cancer recurrence by 22%. The comparison was made with women who were treated with tamoxifen alone, which is the standard treatment to prevent recurrence. Ovarian suppression means blocking the ovaries from producing oestrogen by either radiation, surgically removing them or with injections.

Around 52 patients from Parel’s Tata Memorial Hospital participated in the Suppression of Ovary Function Trial (SOFT) across 501 hospitals in 25 countries. “For young premenopausal women with hormone-sensitive breast cancer, ovarian suppression holds promise. Its benefit is more pronounced in women less than 35 years,” said surgical oncologist Dr Vani Parmar from Tata hospital. She explained the purpose of the study was to establish the efficacy of combining the both.

A secondary analysis in the same trial has found that along with ovary suppression, administering another cancer-preventive drug, exemestane, is even more effective than tamoxifen in cutting down on breast cancer recurrence rate. While 91% of the women on exemestane and ovary suppression function remained free of breast cancer at the end of five years, no recurrence was seen in 88% of women undergoing the tamoxifen and OST treatment. Among those only on tamoxifen, 86% did not show any symptom of recurrence at the end of five years.

But the new treatment is not without some side-effects. Women on exemestane and tamoxifen drugs plus ovary suppression function reported experiencing hot flushes and pain in joints and muscles. Parmar said the study findings might not immediately be made a protocol in hospitals but they showed a way to treat high-risk cancer in young women better. She added they would continue studying the same patients to evolve the treatment options.