At the ASBrS 2025 annual meeting, Dr. Lucy Maria De La Cruz, MD, from Georgetown University Hospital, shared vital insights on male breast cancer treatment. Her talk, “The Forgotten Breast,” covered hormonal differences, effective therapies, and new research like the ETHAN study.
Male Breast Cancer: A Unique Challenge
Male breast cancer (MaBC) is rare but needs specific care. Dr. De La Cruz said, “Mil cancer patients have 80% of their estrogen incomes from peripheral conversion, and 20% comes from their gesticular excretion. It’s very different than women.” Unlike women, who rely on ovarian estrogen before menopause, men depend on peripheral conversion, which is higher than in women after menopause.
Tamoxifen: The Top Choice
Tamoxifen is the main therapy for male breast cancer treatment. Dr. De La Cruz noted, “So currently the standard of therapy and the recommendation is to give tomoxophin for five years for all male breast cancer patients.” The slide “TAM IS ALL THE RAGE!” showed it outperforms aromatase inhibitors (AIs). AIs struggle in men because a hormonal loop increases testosterone, thus raising estrogen. For example, AIs with gonadotropin-releasing hormone analogs only achieve a 25% response rate.
Radiation Therapy Boosts Survival
Moreover, radiation therapy reduces mortality by 27%, per a 2024 study (Colciago et al., n=80,219). It helps node-positive patients after mastectomy (SEER, 1998-2013). However, it’s skipped in 30% of breast-conserving surgery cases, despite being standard (Bakalov et al., 2021).
Compliance Issues in Treatment
Unfortunately, only 70% of eligible patients get estrogen blockers. Of those, 70% stick with it, but half stop within five years due to side effects. Therefore, improving adherence is key to better male breast cancer treatment outcomes.
BRCA and Genetic Insights
Additionally, genetics matter. BRCA2 carriers have a 6% risk, while BRCA1 carriers have a 1% risk. Prophylactic mastectomy isn’t advised for BRCA1 men due to low risk. Instead, BRCA testing guides personalized male breast cancer treatment. The slide deck suggested Tamoxifen for BRCA2 carriers to lower risk.
ETHAN Study: A Game-Changer
The ETHAN study, starting in 2024, tests Tamoxifen, AIs, and CDK4/6 inhibitors. As the “FUTURE DIRECTION?” slide noted, it aims to create male-specific treatments, addressing gaps in female-based data.
Research Gaps
Currently, male breast cancer treatment uses female breast cancer data. Studies like RxPONDER and TAILORx excluded men. For instance, an Oncotype DX score of 21, low for women, links to worse survival in men. A study of 1,800 patients found five MaBC subgroups, one unique to men, suggesting tailored therapies.
Toward Personalized Care
Consequently, Dr. De La Cruz urged recognizing MaBC as distinct. The Male Breast Cancer Coalition pushes for trial inclusion and better adherence. These steps will improve male breast cancer treatment.
Conclusion
Dr. De La Cruz’s May 3, 2025, talk at the ASBrS 2025 annual meeting highlighted advances in male breast cancer treatment. The ETHAN study and male-specific guidelines offer hope. Visit the Male Breast Cancer Coalition for more details.
References:
- Giordano SH. N Engl J Med. 2018;378(24):2311-2330.
- Link: https://www.nejm.org/doi/full/10.1056/NEJMra1707939
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