Estrogen-dependent cancers include breast cancer, ovarian cancer and endometrial (uterine) cancer, which depends on estrogen to develop and grow. Appropriate treatment options can prevent the body from estrogen or hormone receptors from binding to estrogen. It was observed that people who were put on estrogen hormone therapy for managing menopause symptoms are more likely to develop estrogen-dependent cancers.
What Is Estrogen-Dependent Cancer?
Estrogen is a hormone (chemical) that the human body produces, which plays a key role in the normal sexual and reproductive development of women. The ovaries make most estrogen or sex hormones; however, the adrenal glands and fat cells also make some amount of the hormones. Estrogen plays a vital role in regulating the menstrual cycle, reproductive health, urinary tract, heart, bones, breast, skin, hair, pelvic muscles, and brain. But estrogen can also be a carcinogen, which means it has the potential to cause cancer. In estrogen-dependent cancer, this hormone fuels cancer cell growth.
How Does Estrogen Cause Cancers?
Estrogen is known to play a role in causing certain types of tumours. The cells in the human body have hormone receptors, which is a type of protein. Estrogen in the blood can get attached to these receptors and this hormone-receptor process is a part of usual body function. Whereas, in healthy cells, estrogen supports normal cell function and growth. Several factors play a crucial role in turning healthy cells into cancerous and these factors can trigger estrogen and act as a spark. The hormone then causes cancer cells to multiply rapidly and spread.
Risk Factors For Estrogen-Dependent Cancers
Some of the contributing factors that can increase the chances of developing estrogen-dependent cancer include:
- Higher estrogen levels
- Hormone replacement therapy
- Polycystic ovary syndrome (PCOS)
The Link Between Estrogen And Breast Cancer
Around 8 out of 10 breast cancers are hormone receptor positive. These cancers require estrogen, progesterone or both hormones to grow. Excess exposure to estrogen can increase the risk of cancer and exposure can develop due to:
- Hormone replacement therapy for menopause.
- Naturally high estrogen levels.
- Klinefelter syndrome is a genetic condition affecting men.
What Is Hormone Receptor-Positive Breast Cancer?
Around 80% of all breast cancers are “ER-positive”, which indicates the cancer cells grow in response to the hormone estrogen. And 65% of breast cancers are “PR-positive”, where the cancer cells grow in response to another hormone, progesterone. If your breast cancer has a higher number of receptors for either estrogen or progesterone, then it’s considered hormone-receptor positive.
Tumours that are ER/PR- positive are more prone to react to hormone therapy than tumours that are ER/PR- negative. When doctor understands that breast cancer is sensitive to hormones it provides them with better information on how best to treat cancer or avert cancer from recurring.
Hormone Status Of Breast Cancers Includes:
Estrogen receptor (ER) positive: The cells of this type of cancer have receptors that let them use the hormone estrogen to grow. Anti-estrogen hormone (endocrine) therapy can help to impede the growth of cancer cells.
Progesterone Receptor (PR) Positive: This type of cancer is sensitive to progesterone and the cells have receptors that let them use this hormone to develop. Treatment with endocrine therapy prevents the growth of cancer cells.
Hormone Receptor (HR) Negative: This type of cancer does not have hormone receptors, so it won’t be affected by endocrine treatments that are designed at blocking hormones in the system.
The healthcare provider will send tissue samples from a tumour biopsy for a pathology test. The cells in the samples are analysed for the presence of hormone receptors. A positive hormone receptor (HR+) result indicates estrogen, progesterone or both hormones fuel tumour growth.
The healthcare providers decide on treatment options after knowing about the hormone receptor status of cancer. Treatments are more effective on hormone-positive cancers, which include:
Enzyme inhibitors are prescribed that block an enzyme from converting hormones into estrogen. This treatment works for postmenopausal women (who no longer produce estrogen).
Hormone therapies help the body from making estrogen.
Medications that stop hormone receptors from binding to estrogen.
Cancers mostly develop for no known reason, still one can take certain preventive measures to lower the risk of cancer.
- Encourage breastfeeding
- Quit smoking
- Restrict alcohol intake
- Have a wholesome and balanced diet
- Get regular exercise
- Lose weight, if required