Understanding Cervical Cancer - the Basics

What Is Cervical Cancer?

Cervical cancer is cancer of the cervix, the narrow neck at the lower part of a woman's uterus, just above the vagina (Figure 1). It connects the uterus to the vagina.

Approximately 8 out of 10 cervical cancers originate in surface cells lining the cervix (squamous cell carcinomas). These cancers do not form suddenly. In some women, healthy cervical cells become abnormal in appearance -- this is called dysplasia. Although these cells are not cancerous, they can become so.

When dysplastic cells turn cancerous (malignant), the first detectable stage is carcinoma in situ (CIS). As cancer cells multiply, some may invade the lining of the cervix itself, spread to nearby tissue, and enter the bloodstream or lymphatic system and spread to other parts of the body.

Just as it usually takes many years for dysplasia to become carcinoma in situ, it often takes months or even years for cervical cancer to become invasive. (In women with HIV this progression may be faster.) Because of the usual slow progression and because of the Pap smear -- a highly effective, widely available screening test in the United States -- cervical cancer is one of the least threatening forms of cancer and usually easily diagnosed at early stages. When caught early, it is curable. Even in advanced cases, the chance of surviving at least five years, with likelihood of full cure, is still better than 70% . Only when the cancer spreads to distant organs does prognosis for five-year survival dip below 20%. Recurrent cervical cancer carries an even a lower chance of survival.

The American Cancer Society estimates that in 2005, about 10,370 cases of invasive cervical cancer will be diagnosed in the U.S. Noninvasive cervical cancers are more common; it’s estimated that they are four times more common than invasive disease.

The rates of death from cervical cancer continue to decline. Between the mid 1950s and the mid 1990s, the rate declined by 74%. That’s mostly due to the use of the Pap smear for providing a way to sample the cells on the surface of the cervix and detect early abnormal changes. The rate continues to decline today. It is estimated that in 2005, an estimated 3,710 women will die from the disease. In other countries where Pap smears are not used regularly, it is still a common cause of death.

Dysplasia is most likely to occur in women between the ages of 25 and 35, carcinoma in situ between ages 30 and 40, and invasive cancer between ages 40 and 60. Cervical cancer constitutes about 2%- 2.5% of all cancers deaths afflicting American women. Each year about 55,000 cases of carcinoma in situ and about 15,000 cases of invasive cancer are diagnosed.