During the Annual ASCO Meeting, researchers from Loyola University showed anastrozole in comparison to tamoxifen is better to prevent recurrence following radiation therapy and lumpectomy in postmenopausal women aged less than 60 years who had a diagnosis of ductal carcinoma in situ (DCIS). The results were based on a follow-up study conducted in women who participated in the study.

“This study provides a new option for postmenopausal women undergoing treatment for the frequently diagnosed non-invasive breast cancer,” said in a recent news release Kathy Albain, MD, co-investigator on this study, medical oncologist and director of the Breast Cancer Clinical Research Program at Loyola University Chicago Cardinal Bernardin Cancer Center. “These findings will help to better guide treatment decisions for physicians and their patients.”

The study was a Phase III trial that assessed women in their menopause who had a diagnosis of estrogen-receptor or progesterone-receptor positive ductal carcinoma in situ, with no signs of invasive breast cancer following radiation and lumpectomy. Patients where randomised to received a five year treatment of 20 mg per day of tamoxifen or 1 mg per day of anastrozole.

The results showed that after 10 years of follow-up, 93,5% of the patients in the anastrozole treatment group had no tumour recurrence in comparison to 89.2% in patients on the tamoxifen treatment group.

The results also revealed a 77.9% rate of disease-free survival in those patients under tamoxifen treatment versus 82.7% in those receiving anastrozole.

Results of the 10-year follow-up demonstrated an overall survival of 92.1% versus 92.5% for patients who received treatment with tamoxifen or anastrozole, respectively. During the study there was a total of 8 deaths related to breast cancer in the group of patients who received tamoxifen compared to five deaths for those patients who received anastrozole.

“Overall, we can now offer another drug to women who are either at more risk for or wish to avoid some of the uncommon but real side effects of tamoxifen such as blood clots, embolism, stroke and uterine cancer,” Dr. Albain said in the news release. “This is a real step forward in the treatment of non-invasive breast cancer.”