Menopause Hormone Replacement Drugs Linked to Increased Risk of Tumors: Study

Researchers warn that women taking progestin-only HRT may face an increased risk of tumors affecting the central nervous system.

Women taking hormone replacement therapy (HRT) during menopause face an increased risk of developing malignant and benign brain tumors, according to the findings of a new study.

Hormone therapy containing estrogen-only or estrogen and progestin combined increases the risk of developing two types of brain tumors, meningiomas and gliomas, especially with recent use, researchers warn in findings published late last month in the medical journal PLOS Medicine.

Hormone replacement drugs are often used to treat symptoms of perimenopause and menopause. Symptoms can begin 10 years before menopause occurs and often include low energy, hot flashes, cognitive dysfunction, depression, and sleep disturbances. Roughly 80% of women experience menopausal symptoms.

HRT Use Linked to Brain Tumor Risks

In this latest case-controlled study, researchers from Denmark used national data on prescriptions filled by 790,000 Danish women ages 50 to 60 years old from 2000 to 2018, focusing on the risk of brain tumors among women who received HRT treatment.

According to the findings, a total of 1,600 women were diagnosed with meningioma and 1,200 with glioma. Meningiomas are the most common type of brain tumor and are often benign. Gliomas are often malignant and are the most common cancerous brain tumor.

Meningiomas typically grow slowly, but can affect surrounding brain tissue and nerves, leading to symptoms like changes in vision, headaches, hearing loss, memory loss, or seizures. Gliomas can grow quickly and press on brain and spinal cord tissues, causing symptoms like headaches, nausea, vomiting, decline in brain function, memory loss, vision problems, and seizures.

The study indicated women who used oral estrogen-progestin combination hormone therapy like Femhrt and Prempro, or oral progestin-only therapy like Prometrium or Provera, had a higher risk of developing meningiomas than those who did not take HRT. However, the researchers concluded the combination therapy drugs did not increase the risk of gliomas, while progestin-only drugs, like Provera, did.

The data indicated taking combination hormone replacement pills on a continuous basis, instead of cycling on and off, posed a higher risk of meningioma. Additionally, using combination pills for five to 10 years resulted in the highest risk of being diagnosed with meningioma, they concluded.

However, the researchers warned that the highest risk of developing both types of tumors was linked to recent or current use of progestin-only HRT.

HRT Treatment Concerns

Studies have linked estrogen hormone therapy to an increased risk of high blood pressure and increased risk of breast cancer with prolonged use, especially if used outside of the 10 years directly before or after menopause.

In 2012, Pfizer paid more than $1.2 billion to settle lawsuits claiming Prempro, an oral combination therapy of estrogen and progestin, caused women to develop breast cancer.

Additional studies have suggested long-term HRT use may increase a woman’s risk of developing Alzheimer’s disease, especially when women use combination estrogen-progestin oral formulas compared to using the patch or topical formulas.

Prior research has shown HRT for menopause can increase the risk of central nervous system tumors, like brain cancer and spinal cancer. However, the research did not investigate the use of the patch or topical formulations, which often carry lower risks.

“Receptors for both estrogen and progestin are present in meningiomas and gliomas, thus, exogenous exposure to female sex hormones could potentially have an impact on tumor growth,” the researchers concluded. “Further studies are warranted to evaluate our findings and investigate the influence of long-term progestin-only regimens on central nervous system tumor risk.”