Endometrial cancer, also called uterine cancer, usually announces itself by irregular bleeding — sporadic spotting that comes for a few days, goes away, and then comes back again. Sometimes uterine cancer causes heavy bleeding during periods. The cancer grows slowly and is likely to be diagnosed early. When the disease has not spread beyond the uterus, the five-year survival rate is 96 percent.
The principal risk factor for this disease, aside from being female, is age. Most women who get this disease get it after menopause. Ninety-five percent of endometrial cancers occur in women aged 40 or older, and the average age at diagnosis is 60. The relatively few young women who do get endometrial cancer often have problems with ovulation (no menstrual periods, widely spaced or sporadic periods) and some have the masculinizing symptoms of excessive androgens (male hormones). Underlying all these factors is long-term exposure to estrogen, especially without the balancing power of progesterone.
Obesity is also a critical risk factor, because fat tissue makes estrogen. A woman who is seriously overweight is a candidate for endometrial cancer in that her uterine lining is being constantly stimulated not only by the estrogen produced by her ovaries, but also by the estrogen manufactured by her fat. Even after menopause, when her ovaries no longer produce estrogen, her fatty tissue is still at work. Women who are twenty-one to fifty pounds overweight triple their risk; women more than fifty pounds above their normal weight increase their risk tenfold.
Other risk factors include diabetes and high blood pressure, which sometimes but not always are linked to body weight. If you are obese, you are at increased risk for high blood pressure and diabetes; but if you have one of these conditions even if you are not obese, you are still at higher risk for uterine cancer. For example, if you are a slender diabetic, your risk of uterine cancer is somewhat increased. If you are an overweight diabetic (weight control is a problem for many diabetics), you are at significantly increased risk.
Not having children increases risk. If you have had four pregnancies, you are at much lower risk for uterine cancer than someone who has had one child. During pregnancy the hormonal balance shifts toward more progesterone, reducing your endometrial cancer risk. Delayed childbearing also seems to increase risk but not greatly. Women who are at high risk for endometrial cancer are also at increased risk for breast cancer, because the risk factors are similar.
Reliable studies suggest that birth control pills protect you against both uterine and ovarian cancer. Protection is greater if you take oral contraceptives for a long time, and this benefit continues for at least ten years after you stop taking the pill.
An endometrial biopsy or an ultrasound scan can diagnose the condition. During an endometrial biopsy your physician uses a sharp tool or tiny suction device to sample the tissue of your endometrium, which is sent to a pathologist for evaluation. The procedure can be done in the doctor’s office. An ultrasound done through the vagina will show the thickness of the endometrium, a clue to whether or not it is cancerous.
Emma, the mother of three, started having heavy bleeding when she was 30 years old. Emma weighs about 350 pounds, and so my first guess was that she had uterine cancer, at least in its beginning stages. An endometrial biopsy confirmed my guess; she had endometrial hyperplasia, a precursor stage that was not yet actual cancer. I did not want to perform a hysterectomy because Emma’s weight increased her surgical risk, so I started progesterone therapy. After a few months the progesterone made her hyperplasia disappear.
Emma was still spotting between periods, even though biopsies showed that her precancerous condition was gone. Then we discovered that Emma had a small fibroid, only about 1 cm in diameter, under the lining of her endometrium. We removed the fibroid using a hysteroscope. Today she is fine and has no more spotting.
How does endometrial cancer develop?
Before a full-blown cancer of the endometrium develops, the tissues go through precursor stages, just as they do with other cancers. Cancer is classified according to its location and how far it has spread.
Adenomatous hyperplasia is overgrowth of the glandular cells that make up the lining of the uterus. There are more than the normal number of glandular cells in a given sample of uterine tissue, but all of the cells look normal.
Adenomatous hyperplasia with atypia means that there are more than the normal number of glandular cells in a given tissue sample, but that some of these cells look atypical — not normal, but not cancerous. It is adenomatous hyperplasia with atypia that may lead to endometrial cancer.
Adenomatous hyperplasia, even with atypical cells, can be treated without surgery, usually with progesterone. Since adenomatous hyperplasia seems to be a condition of excess estrogen, the addition of progesterone will bring the hormones into balance and actually reverse some of the hyperplasia changes. The customary approach is to try progesterone and have a biopsy in another three months or so to see whether the overgrowth is gone. Because this kind of cancer is not ordinarily fast growing, you and your doctor have the luxury of time to try medical approaches before resorting to surgery.
The Stages of Endometrial Cancer
As with most gynecological tumors, there are four stages of uterine cancer. Stage I disease is basically confined to the body of the uterus and is the easiest to treat. Stage II disease involves the uterus and also the cervix. Although the cervix can be considered part of the uterus, lymph nodes lie close to the cervix and if these are involved, it is possible for the cancer to spread from this location. In stage III disease the cancer has spread beyond the uterus and cervix to other pelvic organs, to the ovaries, to the tissue around the uterus, or to lymph nodes outside the uterus. Stage IV disease has distant metastases. Fortunately we see very little stage IV disease, since the vast majority of women who have endometrial cancer discover it during stage I, while the disease is curable.
Treatment of Endometrial Cancer
The classic therapy for stage I disease is a hysterectomy. Unless there is a very good reason for not doing so, the ovaries are also taken out, since the estrogen they produce stimulates cancerous cells. If cancerous cells are left anywhere in the body, estrogen will cause them to grow. Sometimes the surgeon will take out a few lymph nodes. The uterus is sent to a pathologist, whose report will determine whether follow-up therapy is needed.