Safety of Vaginal Estrogen Therapy for Breast Cancer Patients: New Insights

Breast cancer survivors often experience genitourinary syndrome of menopause (GSM). This condition is frequently undiagnosed and untreated and can start earlier due to cancer treatments. There's been little evidence about the safety of vaginal hormone therapies for women with or at high risk of breast cancer. This has led to avoiding treatment, negatively affecting quality of life and relationships. When deciding on GSM treatment, doctors and patients consider factors like the risk of cancer returning, how severe the symptoms are, how well previous treatments worked, and the patient's preferences.

When the body loses oestrogen, it causes changes in the genital area and vagina. These changes include less cervical fluid, tissue damage, reduced blood flow, loss of elasticity, thinning of tissues, and increased acidity. These changes lead to vaginal dryness, irritation, pain during sex, less interest in sex, frequent urinary tract infections, and bladder control issues. Together, these symptoms are known as GSM.

These symptoms significantly affect quality of life and need proper diagnosis and treatment. For a long time, GSM wasn't diagnosed or treated because of a lack of awareness and limited evidence about safe and effective treatments. Doctors have been hesitant to give hormone replacement therapy to breast cancer patients, worried it might interfere with cancer treatment or cause the cancer to come back. However, many studies show that the risk of cancer returning is very low.

A recent large study provides important information about the safety of vaginal oestrogen therapy for women with breast cancer. This study may reassure both doctors and patients who were worried about using vaginal estrogen products after a breast cancer diagnosis.

The researchers looked at data from 49,237 women aged 40-79 with newly diagnosed breast cancer in Scotland and Wales. They found that 5% of these patients used vaginal estrogen therapy after their breast cancer diagnosis. Importantly, the study found no increased risk of early death from breast cancer among women who used vaginal oestrogen therapy compared to those who didn't use any hormone therapy.

These results are significant because there were concerns that vaginal oestrogen products might increase the risk of breast cancer coming back or getting worse. This large study may help reduce these worries and support guidelines that suggest vaginal oestrogen therapy can be used to treat genitourinary symptoms in breast cancer patients, especially when non-hormonal treatments don't work.

For doctors, these findings can help guide discussions about using vaginal oestrogen therapy for breast cancer patients. For women experiencing distressing genitourinary symptoms due to breast cancer and its treatments, this study may provide the reassurance they need to consider this potentially helpful treatment option.