Adenocarcinoma accounts for about 75 percent of all endometrial carcinomas. It occurs most often in women 50 to 70 years of age.
The remaining three types of endometrial carcinoma have a poor prognosis. Approximately 15 percent of woman have adenosquamous carcinoma, in which both the gland cells and squamous cells are malignant.
Three percent have a clear cell carcinoma, and about one percent have a papillary carcinoma. Uterine sarcoma is another kind of uterine malignancy.
From where it arises in the lining of the uterus, untreated endometrial carcinoma eventually invades the wall of the uterus and may involve the cervix. With time, it can grow through the wall of the uterus into the surrounding tissues (the parametrium), the bladder and the rectum.
It also can spread by the lymphatic system to the vagina, fallopian tubes, ovaries, the pelvic and aortic lymph nodes and to the lymph nodes in the groin and above the collarbone (supraclavicular).
Some patients will have taken unopposed (without progestin) estrogen in the past. Their increased risk may persist for 10 years or more after stopping the drug.
Obesity, nulliparity (having borne no children), diabetes, and polycystic ovaries with prolonged anovulation (lack of menstruation), and extended use of tamoxifen for treatment of breast cancer also are risk factors.
Endometrial cancer rarely occurs before menopause, when a woman is having regular menstrual periods, but it does occur around the time that regular menstruation stops. The reappearance of bleeding should not be considered simply part of the change of life. It should always be brought to a doctor's attention so he or she can rule out the possibility of cancer.
Abnormal bleeding from the uterus after menopause is the most common symptom of endometrial cancer. The bleeding may start as a watery, blood-streaked discharge that eventually contains more blood.
Abnormal menstrual bleeding in premenopausal women also should be reported to their physician. In some women, there also may be lower abdominal pain.
Endocervical and endometrial sampling is the only reliable means of diagnosis.
Vaginal ultrasonography may be used to determine the thickness of the endometrium since increased thickness may indicate cancerous change.
The Pap test, which is very accurate in detecting cervical cancer, is not a reliable means of detecting endometrial cancer. This is because abnormal cells shed by the endometrium degenerate (lose their characteristic features) before they reach the vagina.
Treatment of endometrial carcinoma is based primarily on the stage and grade of the cancer.
The standard therapy is an abdominal hysterectomy (surgical removal of the uterus) with removal of both fallopian tubes and ovaries, selective removal of pelvic and aortic lymph nodes and washings from the abdominal cavity to look for malignant cells.
Most gynecologic oncologists (doctors who specialize in pelvic cancers) also recommend obtaining a specimen from the cancer for analysis of its estrogen and progesterone receptor content. The receptor content has prognostic value and may be useful in the selection of hormone therapy for recurrent or metastatic cancer.
Some women also may receive radiation therapy.