Uterine cancer includes both cervical cancer and endometrial cancer, cancer of the lining of the uterus. Nearly 49,000 women in the United States and 5,000 women in Canada are diagnosed with uterine cancer each year. The single greatest risk factor for cervical cancer is infection with the human papilloma virus (HPV). Other risk factors include sexual intercourse before age 18, having many sexual partners, and cigarette smoking. For reasons that are not entirely clear, the disease also seems to be more common in women of low socioeconomic status.
Endometrial cancer symptoms are similar to those of cervical cancer. Most often, they start with a watery vaginal discharge that has streaks of blood. In the United States, the five-year survival rate for endometrial cancer is 83 percent but climbs to 96 percent if the cancer is caught and treated at an early stage.
There are two main types of cancer of the cervix, the lower part of the uterus. Squamous cell carcinomas make up 85 to 90 percent of these cancers. The other 10 to 15 percent are adenocarcinomas. Most cervical cancers develop slowly and may not produce any noticeable symptoms in the early stages. As the cancer progresses, the woman may experience a watery vaginal discharge and painless bleeding. Over time, the bleeding becomes heavier and more frequent, and pain becomes noticeable in the lower abdomen or back. The five-year survival rate for cervical cancer in the United States is 71 percent but rises to 91 percent if the cancer is detected early. For unknown reasons, black women are twice as likely to die of the disease than are white women in the United States.
Nearly all endometrial cancers are adenocarcinomas. The risk of developing endometrial cancer is higher in women who take certain hormones during estrogen replacement therapy. Other risk factors include early onset of menstruation and late menopause, probably because these factors increase the number of years during which the endometrium is exposed to estrogen and other steroid hormones. Obesity also increases the risk of endometrial cancer, probably because excess fat can increase the level of estrogens in a woman’s body. Excess weight of 14 kg (30 lb) triples a woman's endometrial cancer risk. Similarly, diseases more common in women who are overweight, including diabetes mellitus and gallbladder disease, are also associated with a higher risk of endometrial cancer.
A component of the female reproductive system, the uterus is a muscular organ with an expandable neck called the cervix. Two main types of cancer arise in the uterus—endometrial cancer orignates in the lining of the uterus, while cervical cancer begins in the epithelial cells of the cervix.