Higher Estrogen Levels May Increase Your Risk of Endometrial Cancer
While we cannot yet pinpoint exactly what causes endometrial cancer, studies do suggest that higher levels of estrogen may be associated with endometrial cancer development. Estrogen is a naturally occurring hormone made in the ovaries, along with another hormone called progesterone. In a woman who has not yet started menopause, these hormone levels fluctuate during the monthly cycle. However, during and after menopause, the body stops producing these hormones. This is what causes the effects of menopause, like hot flashes, night sweats, and vaginal dryness.These are some of the reasons you might have elevated estrogen levels:
- Estrogen-Only Hormone Therapy: To alleviate these bothersome side effects of menopause, some women are prescribed hormone replacement therapy, either estrogen or estrogen along with progestin (a synthetic version of progesterone), depending on whether or not they still have their uterus. Estrogen can cause the lining of the uterus to grow (endometrial hyperplasia) if a woman still has her uterus, so she will need to take progestin to counteract it. There is a risk of developing uterine cancer if this occurs. Thus, taking estrogen without the aid of progestin if you still have a uterus may increase your risk of endometrial cancer.
- Obesity: Even though the ovaries are no longer producing estrogen after menopause as they once were, estrogen can still be found in the body in adipose tissue (fat). This is normal for all women. Researchers believe that because obese women have more adipose tissue, they are at an increased risk of developing endometrial cancer because they have higher levels of estrogen. Unfortunately, women who are obese and also have endometrial cancer also suffer from an increased risk of death from the disease. Keep in mind that women at healthy weights are also vulnerable to endometrial cancer -- it isn't exclusive to obese women.
- Many Years of Menstruation: Starting menstruation early or beginning menopause late also increases your risk of endometrial cancer. Again, estrogen is a factor in why this may increase your risk. In menstruating women, the endometrium is exposed to estrogen every cycle. The more cycles you have, the more estrogen exposure your endometrium experiences.
- PCOS or Irregular Ovulation: Women who experience irregular ovulation, like those who suffer from polycystic ovary syndrome (PCOS), face an increased risk of endometrial cancer. In these women, estrogen is being produced and stimulating the growth (thickening) of the endometrial lining. However, if ovulation does not occur, the endometrial lining is not shed (as in normal, ovulating women) and is exposed to more estrogen. The result can be endometrial hyperplasia, which can lead to endometrial cancer.
- Never Being Pregnant: Women who have never been pregnant are at an increased risk, especially those who suffer from infertility. The thinking behind this risk factor is that women who have never been pregnant may experience irregular ovulation, which is explained above.
- Tamoxifen Use: Tamoxifen is an adjuvant therapy drug often prescribed for women with breast cancer. It binds to estrogen receptors in some tissues, blocking estrogen from binding and stimulating tissue growth. We know that estrogen, like in endometrial cancer, can fuel cancer growth in some women with breast cancer. Unfortunately, Tamoxifen can stimulate the growth of the endometrium.
Other Endometrial Cancer Risk Factors
Estrogen is not the only risk factor of endometrial cancer. Researchers have identified other risk factors for the disease:
- Being Diabetic: Research shows that women who are diabetic are at an increased risk of endometrial cancer. This could be because obesity and diabetes are related.
- Personal Health History of Breast or Ovarian Cancer: Women who have had breast or ovarian cancer a have small risk of developing endometrial cancer. The three diseases all share similar risk factors.
- Lynch Syndrome: Lynch syndrome is an genetic condition that increases a person's risk of cancer, especially colon cancer. Also known as HNPCC (hereditary nonpolyposis colorectal cancer), lynch syndrome primarily affects the digestive tract, but also increases the risk of of ovarian and endometrial cancer in women.
