Women may reduce the risk of their breast cancer returning by starting treatment with Femara (letrozole) anywhere from one to seven years after finishing tamoxifen therapy, according to a new analysis published in the Journal of Clinical Oncology.
The exploratory analysis of post-unblinding results from the landmark MA-17 trial, led by the National Cancer Institute of Canada Clinical Trials Group, evaluated a subset of women in the original placebo group when the study was unblinded.
The analysis shows that women who started Femara several years after completing the recommended five years of tamoxifen reduced their risk of breast cancer coming back by 63% compared to those who did not start Femara. In addition, the risk of cancer spreading to other areas of the body was reduced by 61%. The median period before starting Femara was 31 months.
“The important message for women is that it may never be too late for many breast cancer survivors to do more to protect themselves against the ongoing risk of disease recurrence,” said Paul Goss, M.D., PhD., of the Massachusetts General Hospital in Boston and the lead investigator of MA-17. “These data reinforce the need for women diagnosed with breast cancer to go back to their doctors and continue to discuss ways to reduce their risk of recurrence.”
More than 50% of breast cancer recurrences and deaths occur five or more years after completing tamoxifen treatment. Femara is the only drug in the aromatase inhibitor class with data showing its potential to reduce the risk of breast cancer returning even when started several years after initial treatment with tamoxifen.
Results from this analysis affirm the safety and efficacy of Femara as extended adjuvant therapy (i.e. following the completion of five years of tamoxifen).
Source: Novartis, USA