Reevaluating Hormone Replacement Therapy in Breast Cancer Survivors: New Expert Perspectives

Breast cancer survivors experiencing severe menopausal symptoms face a complex decision regarding hormone replacement therapy (HRT). An interdisciplinary panel of experts, including researchers from University College London, emphasizes the importance of individualized, informed decision-making in this context. Their study, published in the journal Menopause, offers a comprehensive review of existing evidence concerning HRT's safety and efficacy for women who have undergone breast cancer treatment.

Breast cancer remains the most prevalent cancer among women worldwide, with over 2.3 million new cases annually. Thanks to advances in treatment, survival rates have improved significantly, resulting in more long-term survivors—over 700,000 in the UK alone. Many of these women endure severe menopausal symptoms, such as hot flashes, insomnia, mood swings, and genitourinary issues like vaginal dryness and recurrent urinary infections. These symptoms can significantly impair quality of life.

Traditionally, HRT, known also as menopausal hormone therapy (MHT), has been discouraged for breast cancer survivors due to the estrogen component's potential to increase the risk of cancer recurrence, especially in estrogen receptor-positive breast cancers which account for 70–80% of cases. NICE guidelines recommend that HRT be used only in exceptional circumstances for these women.

The recent study brings new insights, highlighting that vaginal estrogen, which has minimal systemic absorption, is unlikely to elevate the risk of recurrence and can effectively treat genitourinary symptoms. Conversely, systemic HRT, involving estrogen, progesterone, or testosterone, may heighten the risk of relapse, particularly within the first 5 to 10 years post-diagnosis. However, the increased risk primarily relates to local recurrence, which is usually treatable, and the impact on distant metastases appears limited.

Using evidence from randomized trials like HABITS and the Stockholm Study, the panel found that for women with moderate-risk breast cancer, HRT increases relapse risk from 14% to 20%, but the majority of women will not recur. For low-risk patients, relapse rates rise modestly from 5% to 7.2%. Crucially, the overall increase in dangerous distant relapses remains small—raising the 7-year rate from 5.8% to 6.3% in moderate-risk cases.

The expert consensus underscores the importance of shared decision-making. Women should receive comprehensive information about their personal risks and benefits, enabling them to weigh symptom relief against potential recurrence risks. The panel advocates for more clinical trials, such as the proposed MENO-ABC study, to gather long-term safety and outcome data.

Professor Jayant Vaidya from UCL highlights the paradox: while estrogen is effective in alleviating menopause symptoms, it can stimulate breast cancer growth. The consensus now leans toward moving away from an outright ban, favoring nuanced discussions tailored to individual risk profiles. Dr. Sarah Glynne emphasizes that women should be empowered with accurate information to make choices aligned with their preferences, considering their health risks and quality of life.

Overall, this evolving perspective aims to balance the need for symptom relief with safety considerations, ultimately supporting personalized menopause care for breast cancer survivors.

Source: [https://medicalxpress.com/news/2025-09-experts-heart-hormone-therapy-breast.html]