Guest Author - Dr. Denise Howard
Risk factors are specific elements that seem to be associated with a defined outcome. Most diseases tend to have associated factors and these can lead to the identification of causative agents. Endometrial cancer has specific risk factors and this article will discuss this in more detail.
As with most diseases, age is the most notable risk factor. The risk of endometrial cancer increases with age and is more common in postmenopausal women. The risk is 6% in women age 35-44. This increases dramatically with each subsequent decade. At age 45-54 the risk is 19% and then peaks to a high of 33% at 55-64. The lifetime risk then falls after this.
The other major risk factor is estrogen. This factor appears to be causative in more than 80% of the cases of endometrial malignancy. Thus any condition, which leads to an excessive amount of estrogen, can contribute to the development of endometrial cancer. Such conditions include obesity, chronic anovulation, exogenous unopposed estrogen use and medications with have estrogen-like effects on the endometrium.
Obese women have a greater amount of circulating estrogen due to the peripheral conversion of precursor chemicals to estrogen by the adipose cells. This estrogen can stimulate disproportionate endometrial growth, which could then lead to abnormal cell changes and cancer. In addition, the excessive estrogen has a negative feedback on the central reproductive regulator center in the brain, suppressing ovulation and preventing the normal cycle of progestin production, which normally has a protective effect on the endometrium and drives menstruation. Without menstruation, the tissue continues to grow and has an opportunity to undergo malignant changes.
Women who take estrogen replacement therapy without the use of progestin to counter its effect on the endometrium are more likely to develop cancer. This is described as unopposed estrogen. Women who elect to take hormone replacement therapy should make sure they also receive a progestin in addition to the estrogen if they still have their uterus. Finally, Tamoxifen, which is used to treat breast cancer, has an estrogen like effect on the endometrium and is capable to causing endometrial cancer. As previously mentioned, abnormal bleeding is the first sign of this malignancy.
Anovulation or infrequent menstruation can lead to the development of endometrial cancer via the mechanism described above for obese women. If ovulation does not occur then the normal cycle of menstruation is prevented, allowing continued unopposed growth of the endometrium.
The other factors that have been found to be associated with the development of endometrial cancer include: women who have never been pregnant, early age of menstruation and late menopause. There are hereditary cancer syndromes, which increase the risk of cancer. The most commonly identified is Lynch Syndrome, which is manifested as hereditary nonpolyposis colorectal cancer and confers a lifetime risk of endometrial cancer of 27-71%. It also increases the risk of ovarian cancer.
Protective factors are those that decrease the risk of developing a disease. Protective factors for endometrial cancer include pregnancy, oral contraceptive pills, and later age of child bearing. Opportunities for prevention also include weight control and promptly seeking care if you have irregular menstrual cycles.
Endometrial cancer is one of the more common gynecologic cancers. As with all medical problems: awareness, early detection, and prompt treatment are the keys to saving lives.
I hope this article has provided you with information that will help you make wise choices, so you may:
Live healthy, live well and live long!