Impaired sexual function and quality of life were associated with decreased estradiol levels as a result of dual therapy with gonadotropin-releasing hormone analogue (GnRHa) for men with breast cancer. These findings from a phase 2, randomized clinical trial were published in JAMA Oncology.

The extent of changes on estradiol levels in men with hormone receptor-positive breast cancer due to standard endocrine therapy are unknown. Therefore, researchers sought to determine the effect of those changes on sexual function and quality of life in this patient population.

In the study, 56 men with hormone receptor-positive breast cancer were randomized in a 1:1:1 ratio to receive 20 mg tamoxifen daily, 20 mg tamoxifen daily with GnRHa, or 25 mg aromatase inhibitor (AI) daily with GnRHa. GnRHa was administered subcutaneously every 3 months. The participants were assessed at 3 and 6 months for hormone levels and quality of life.

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Patients were median age 61.5 (range, 37-83) with ERBB2-negative (86.5%), G2 (57.7%), T2 (52.9%), and node-negative (52.0%) tumors.

At 3 months, 17-b-Estradiol increased by 66.7% among patients receiving tamoxifen monotherapy and decreased by 84.9% and 72.2% among the tamoxifen or AI with GnRHa recipients, respectively (P =.01). Estradiol levels were significantly higher among the monotherapy recipients compared with either dual therapy group (P <.001).

Erectile dysfunction increased from 34.6% of patients at baseline to 61.7% (P <.001) at 6 months. Quality of life was reported to be reduced in 67.4% of patients at 6 months. No patient in the monotherapy group reported new erectile dysfunction and only 2 reported reduced quality of life, indicating these patterns were driven primarily by the dual therapy recipients.

This study was limited by not evaluating cancer treatment outcomes.

These findings indicated dual therapy with GnRHa increased adverse effects on sexual function and quality of life, making GnRHa a poor treatment option for men with breast cancer.

Disclosure: Multiple authors declared affiliations with or received funding from the pharmaceutical industry. Please refer to the original article for a full list of disclosures.


Reinisch M, Seiler S, Hauzenberger T, et al. Efficacy of endocrine therapy for the treatment of breast cancer in men: results from the MALE Phase 2 Randomized Clinical Trial. JAMA Oncol. Published online February 4, 2021. doi:10.1001/jamaoncol.2020.7442