2X MATCH: 2X Match Today, your gift is DOUBLED for 2X the impact on lifesaving research.
Clear Search

Meredith M. Regan, ScD

International Breast Cancer Study Group
Bern, Switzerland

Titles and Affiliations

Associate Professor of Medicine, Division of Biostatistics
Dana-Farber Cancer Institute and Harvard Medical School

Research area

Assessing the long-term effects and survival benefits of anti-estrogen therapies in premenopausal women.


Results from two international clinical trials—the Suppression of Ovarian Function Trial (SOFT) and the Tamoxifen and Exemestane Trial (TEXT)—led to new clinical guidelines for the treatment of estrogen receptor (ER)-positive breast cancer in premenopausal women. The initial results from the trials supported the use of ovarian suppression drugs in addition to anti-estrogen therapy to preserve fertility in women who intended to have children after treatment. However, further follow-up is needed to fully understand the implications of treatment decisions on overall survival and late side effects of therapy. With support from BCRF, Dr. Regan and her colleagues at the International Breast Cancer Study Group are able to extend the follow-up of all women participating in SOFT and TEXT to a minimum of 10 years. Their results will be important in clinical decision making for young women with ER-positive breast cancer.

Progress Thus Far

After ten years of follow-up, results from the SOFT and TEXT trials showed improved recurrence-free and overall survival outcomes for young breast cancer patients treated with ovarian suppression drugs plus tamoxifen, compared to tamoxifen alone. Those at highest risk of recurrence received greater benefits. The use of exemestane (an aromatase inhibitor) plus an ovarian suppression drug resulted in even lower rates of recurrence. The team examined the genomic characteristics of 1,276 early breast cancers from patients in SOFT and showed unique genomic characteristics in premenopausal women under 40 which correlated with their poorer prognoses.

What’s next

Dr. Regan and her colleagues will continue to follow patients from the SOFT and TEXT trials. Longer follow-up remains critical to ensure the efficacy of ovarian suppression in the reduction of late recurrence and identify any long-term side effects. In addition, longer follow-up will enhance the reliability of biomarker research studies to be conducted using patient samples from the studies. This will help inform discussions between patients and doctors regarding the benefits of more intensive treatment versus the resultant side effects.


Meredith Regan, ScD is Associate Professor of Medicine, Division of Biostatistics, Dana-Farber Cancer Institute and Harvard Medical School. She is the Director, Statistical and Data Management Center for the International Breast Cancer Study Group (IBCSG), a Swiss non-profit research organization dedicated for over 40 years to innovative clinical research to improve treatment options and the quality of life of breast cancer patients. Since 2003 she has been the lead statistician for the IBCSG’s SOFT and TEXT phase III clinical trials. Together with the trials’ co-chairs, she has led the analysis and reporting of the trials’ primary efficacy results—supporting the use of aromatase inhibitor (AI) with ovarian function suppression (OFS) as adjuvant endocrine therapy option for premenopausal women, and clarifying the role of OFS in addition to tamoxifen. She continues in this role as the trials continue to collect longer-term patient follow-up to understand the impact of these therapies on late recurrence and survival and any associated late side effects of the therapies. Dr. Regan’s research interests extend to clinical-translational investigations to individualize endocrine therapy treatment selection, and clinical trial design and endpoints.

BCRF Investigator Since


Donor Recognition

The Estée Lauder Companies’ North American Research & Development and Supply Chain Award

Areas of Focus