The results of Breast International Group 1-98 (BIG 1-98) published in the New England Journal of Medicine showed that letrozole reduced the risk of breast cancer returning by an additional 19 percent over the reduction offered by tamoxifen.
Furthermore, patients taking letrozole showed 27 percent reduction in the risk of the cancer spreading to distant parts of the body.
"One of the greatest fears confronted by women who have been treated for early breast cancer is that their cancer will come back," said Dr. Matthew Ellis, section head of the Medical Oncology Division in the Department of Medicine at Washington University in St. Louis.
"With letrozole we now have an option that can help address that fear early on, even in patients who we know face the greatest risk of recurrence," Ellis said.
In addition, BIG 1-98 showed that women with metastatic breast cancer who were given letrozole as first-line treatment had a significantly higher response rate, longer time for disease progression and significant improvement in one to two-year survival rates compared to others who were given a different drug.
Due to the favorable results of the BIG 1-98 study, the US Food and Drug Administration has approved the use of letrozole as adjuvant treatment immediately after surgery among post-menopausal women with hormone-sensitive early breast cancer.
In the Philippines, the Bureau of Food and Drug Administration has also approved the use of letrozole for the same indication.
According to Dr. Diane Young, vice president and global head of Clinical Development at Novartis Oncology, letrozole has consistently demonstrated superiority over tamoxifen as first-line therapy in women with metastatic breast cancer as well as in post-menopausal women with hormone-sensitive early breast cancer.
"In addition, letrozole provides a notable benefit to patients who are especially high risk of having their breast cancer return," she said.
Patients are informed that letrozole, along with all drugs for breast cancer, is a prescription product and should only be taken upon a doctor’s advice.