From the Guidelines
If you're experiencing gynecomastia due to hormone-modifying cancer treatments, breast bud irradiation (8-10 Gy in one fraction) should be considered to prevent painful gynaecomastia, as recommended by the Annals of Oncology in 2009 1. This approach is particularly relevant for patients receiving long-term bicalutamide monotherapy. For managing gynecomastia, the following options can be considered:
- Adjusting medication dosage or switching to an alternative treatment without compromising cancer care
- Using a supportive bra or compression garment for mild cases
- Prescribing medications like tamoxifen or raloxifene to reduce breast tissue growth
- Considering surgical options such as liposuction or mastectomy for severe or persistent cases after cancer treatment is complete It's essential to consult an oncologist to discuss the best management options, as the primary goal remains effective cancer treatment. The development of gynecomastia is a result of hormone therapies disrupting the balance between testosterone and estrogen, leading to male breast tissue growth. Regular follow-up and monitoring are crucial to manage this side effect and ensure the best possible outcome for patients with hormone receptor-positive metastatic breast cancer, as outlined in the Journal of Clinical Oncology in 2021 1. Additionally, lifestyle factors such as regular exercise and nutritional counseling can play a significant role in improving prognosis and overall quality of life for patients with breast cancer, as suggested by the Annals of Oncology in 2015 1 and 2013 1. However, the most recent and highest quality study, published in 2021 1, should be prioritized when making definitive recommendations. Therefore, breast bud irradiation (8-10 Gy in one fraction) is the recommended approach for preventing painful gynaecomastia in patients receiving long-term bicalutamide monotherapy, as it is supported by the strongest and most recent evidence 1.
From the FDA Drug Label
The efficacy of anastrozole in the treatment of pubertal gynecomastia in adolescent boys and in the treatment of precocious puberty in girls with McCune-Albright Syndrome has not been demonstrated. A randomized, double-blind, placebo-controlled, multi-center study enrolled 80 boys with pubertal gynecomastia aged 11 to 18 years Patients were randomized to a daily regimen of either anastrozole 1 mg or placebo. After 6 months of treatment there was no statistically significant difference in the percentage of patients who experienced a ≥50% reduction in gynecomastia
The FDA drug label does not provide guidance on what to do if hormone modifiers for cancer cause gynecomastia. However, it does mention that anastrozole was studied for the treatment of pubertal gynecomastia in adolescent boys, but its efficacy was not demonstrated.
- Key points:
- Anastrozole was not effective in treating gynecomastia in adolescent boys.
- The study did not demonstrate a statistically significant difference in the percentage of patients who experienced a ≥50% reduction in gynecomastia.
- No conclusion can be drawn on how to manage gynecomastia caused by hormone modifiers for cancer based on the provided drug labels 2 2.
From the Research
Treatment Options for Gynecomastia
- Medical treatment with antiestrogens and aromatase inhibitors can alleviate or prevent the development of gynecomastia 3
- Mastectomy with excision of the gland, liposuction, or an association of the two techniques have proved to be effective in treating gynecomastia 3
- Radiation therapy may provide effective relief from the breast pain associated with gynecomastia 3, 4, 5
- Tamoxifen 20mg/day can lead to a significant decrease in the mammary effects of gynecomastia and is considered the best treatment and prevention option 4, 5, 6
- Surgical liposuction can be considered an effective treatment for gynecomastia, especially in the very early stages 3
Prevention of Gynecomastia
- Prophylactic radiation therapy (RT) using 1 × 10 Gy or 2 × 6 Gy can significantly reduce the rate of gynecomastia 5
- Prophylactic daily tamoxifen (TMX) can reduce the risk of gynecomastia and/or breast pain 5
- Physical examination is a fundamental tool for all patients before initiating treatment with antiandrogens to detect gynecomastia early 4
Comparison of Treatment Options
- Tamoxifen appears to be more effective than radiation therapy in reducing the risk of gynecomastia and/or breast pain 5
- Tamoxifen is more effective than anastrozole in reducing the risk for gynecomastia and/or breast pain 5
- The rate of side effects after tamoxifen, including dizziness and hot flushes, might be higher than after radiation therapy 5