What is Menopausal Hormone Therapy?
Menopausal Hormone Therapy (MHT) is widely prescribed for postmenopausal women to ease symptoms of menopause such as hot flashes, vaginal dryness, and sleep disturbances.
There are two types of Hormone Replacement Therapy (HRT):
- Combination Hormone Replacement Therapy: Involves the administration of estrogen and progesterone
- Estrogen-Only Therapy: Involves the administration of estrogen in the form of pills, patches, or topical creams
According to recent research, it has been found that Combination Menopausal Hormone Replacement Therapy increases the risk of breast cancer by 75%, even when administered for a very short time. In contrast, estrogen-only hormone therapy increases the risk of breast cancer only when used for longer than 10 years.
What Are The Health Effects Of Menopausal Hormone Therapy?
- Women who took hormone therapies had reduced risk of hip and vertebral fractures but increased risk of urinary continence and cardiovascular diseases, including blood clots, strokes, and heart attack.
- Women who took combination hormone therapy had greater vaginal bleeding that needed further investigation.
- Women over 65 years of age, who took either of the menopausal hormone therapies, had an increased risk of developing dementia.
- Hormone therapies made mammography less effective for the early detection of breast cancers. This increases the need for repeat mammograms and breast biopsies to diagnose cancerous lesions.
How Does Genetics Influence Breast Cancer Risk with Menopausal Hormone Therapy?
Some genes promote higher growth of estrogen receptors during menopausal hormone therapy. This increases the risk of ER-positive breast cancer.
The CYP19A1 Gene
The CYP19A1 gene contains instructions for the production of a protein involved in estrogen biosynthesis.
Certain changes in this gene are associated with poor treatment outcomes of hormone therapy in women in the early stages of ER-positive breast cancer.
The POMP Gene
The POMP gene contains instructions for the production of proteasome maturation protein. A study revealed two regions in the POMP gene showing interaction with hormone therapy that increased the risk of breast cancer.
Non-genetics Factors that Influence Breast Cancer Risk with Menopausal Hormone Therapy
Obesity: According to a study published in Cancer Epidemiology Biomarkers in 2008, both types of hormone therapy are associated with breast cancer risk. The risk is further influenced by the body mass of the individual and the clinical characteristics of the tumors.
In women with BMI <25 kg/m2, estrogen therapy was associated with a 60% increase in breast cancer risk after 10 years of the therapy. The risk increased with combined therapy. Combined therapy with estrogen and progesterone was also strongly associated with ER-positive tumors.
Alcohol consumption: Drinking alcohol while taking postmenopausal hormone replacement therapy can increase the risk of developing breast cancer. This is because drinking alcohol increases estrogen levels, and when combined with the estrogen in hormone therapy, it significantly increases estrogen in a woman’s body.
A study was conducted to analyze drinking habits and hormone therapy use in over 5,000 Danish women for over 20 years. The researchers found that postmenopausal women who took Hormone Replacement Therapy (HRT) and drank 1 or 2 alcoholic drinks per day had three times higher risk of breast cancer than women who did not drink and were not taking HRT. Also, postmenopausal women taking HRT who drank more than 2 alcoholic drinks per day had a five times higher risk of breast cancer than women who did not drink and were not taking HRT.
Smoking: Smoking has been associated with an increased risk of breast cancer in women. This risk is much higher for women who smoke while taking postmenopausal hormone therapy.
Recommendations
- Consider Alternatives to Hormone Replacement Therapy: If you have been diagnosed with breast cancer or are at an increased risk of developing it due to abnormal changes in the BRCA1 and/or BRCA2 genes, consider alternatives to Hormone Replacement Therapy.
- Maintain a healthy weight: Increased BMI and weight increases the risk of developing breast cancer in postmenopausal women on hormone therapy.
- Eat nutritious food: Eating foods rich in antioxidants, fiber, and vitamins A, C, and D. Soya-bean-based foods and low-fat milk and dairy products are recommended. Avoid foods with excessive sugar, fat, red meat, and processed foods as they increase the risk of developing breast cancer in menopausal women undergoing hormone therapy.
- Avoid alcohol and quit smoking: Alcohol consumption and smoking have both been associated with an increased risk of developing breast cancer.
- Identify the trigger for hot flashes: Spicy foods, caffeine, alcohol, and sugary foods can trigger hot flashes, especially at night. So limit/avoid their consumption.
Summary
- Menopausal Hormone Replacement Therapy (HRT) is given to postmenopausal women to help them deal with symptoms of menopause.
- HRT is of two types – Combination Therapy that involves the administration of progesterone and estrogen, and Estrogen Therapy, in which only estrogen is given.
- Combination HRT, when used for a short time, is known to increase breast cancer risk by 75%.
- There are many side effects of Hormone Replacement Therapy, including an increased risk of breast cancer.
- Genetics has a strong role in the development of breast cancer in postmenopausal women taking hormone replacement therapy.
- Non-genetic factors like obesity, alcohol consumption and smoking also increase the risk of breast cancer in women taking HRT.
- Eating a nutritious diet, maintaining a healthy weight, and undergoing routine screening are advised to reduce the risk of breast cancer in these women.
- Women who have a personal and family history of breast cancer must avoid taking Hormone Replacement Therapy.
