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Cervical cancer develops when the cells of the cervix grow out of control. Unlike normal cells, which divide and grow in an organized fashion, malignant cancer cells continue to divide until they form a growth or tumor (a mass of excess tissue). In some cases, the cancer cells become invasive, spreading to tissues and organs outside of the cervix (metastasis).
The cervix is the bottom part of the uterus (womb). During pregnancy, the fetus grows in the top part (body) of the uterus. The cervix connects the uterine body to the vagina (birth canal). The part of the cervix that is closest to the uterine body is known as the endocervix. The part of the cervix that is next to the vagina is called the ectocervix. The majority of cervical cancers begin where the endocervix and ectocervix meet.
Most cervical cancers develop slowly, in the lining of the cervix. Healthy cervical cells develop abnormal precancerous changes over time known as cervical dysplasia. These cells can potentially develop into cancer. Precancerous cells often do not become malignant (cancerous), and may disappear without treatment. Abnormal cells that remain can be treated to prevent cervical cancer. If the cancer is not treated in this earliest stage in the lining of the cervix, it can invade other cervical tissue and is considered invasive cervical cancer.
An estimated 11,00 cases of invasive cancer of the cervix were estimated to be diagnosed in the United States in 2007, according to the American Cancer Society (ACS). Cervical cancer has a higher incidence among certain populations, including Vietnamese American, black and Hispanic women, according to the U.S. Centers for Disease Control and Prevention (CDC). In addition, women with fewer opportunities for regular gynecological examinations and screening also have a higher risk for the disease. According to some researchers, noninvasive cervical cancer (carcinoma in situ) is approximately four times as prevalent as its invasive counterpart.
Cancer of the cervix tends to occur during midlife, with half of patients diagnosed between 35 and 55 years of age. Cervical cancer rarely affects women under the age of 20 years. Because more than 20 percent of women are diagnosed with cervical cancer after they reach age 65, it is important for women to have annual Pap tests until age 70, and sometimes longer. Cervical cancer affects a small number of pregnant women. If the cancer is in an early stage, most physicians believe that expectant mothers can safely carry their baby to term.
Cervical cancer was once among the leading causes of death of American women. However incidences of invasive cervical cancer have declined steadily over the years in developed countries. In the United States, only about 3,700 women are expected to die from invasive cervical cancer during 2007.
The U.S. death rate from this condition continues to decrease by nearly 4 percent a year. Between 1998 and 2002, the overall rates of women in the United States diagnosed with invasive cervical cancer declined 17 percent, according to the ACS. This decline is primarily attributed to increased use of the Pap smear, a screening procedure that detects cervical changes before cancer develops. However, higher rates continue to exist among the Hispanic and black women.
Healthcare professionals hope that widespread use of the FDA-approved human papillomavirus (HPV) vaccine will contribute to a continuing decline in the incidence of cervical cancer. Research has shown that this vaccine is effective against the types of HPV associated with 70 percent of cervical cancers.
The five-year survival rate of this disease is about 72 percent. When detected at its earliest stage, invasive cervical cancer has a much higher survival rate of 92 percent.
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Cervical Cancer