Cervical cancer

2006-Sep-15
by JACK DANIELS

Cervical cancer is a disease in which the cells of the cervix become abnormal and start to grow uncontrollably, forming Cervical cancer.Cervical cancer is the second most common malignancy in women worldwide, and it remains a leading cause of cancer-related death for women in developing countries. In the United States, cervical cancer is relatively uncommon. The incidence of invasive cervical cancer has declined steadily in the United States over the past few decades; however, it continues to rise in many developing countries. The change in the epidemiological trend in the United States has been attributed to mass screening with Papanicolaou tests (Pap smears).

Worldwide, there are more than 400,000 new cases of cervical cancer diagnosed each year. The American Cancer Society (ACS) estimated 13,000 new cases of invasive cervical cancer in the United States in 2002. More than one million women were diagnosed with a precancerous lesion or non-invasive cancer of the cervix in 2001.

Older women are at the highest risk for cervical cancer. Although girls under the age of 15 rarely develop this cancer, the risk factor begins to increase in the late teens. Rates for carcinoma in situ peak between the ages of 20 and 30. In the United States, the incidence of invasive cervical cancer increases rapidly with age for African-American women over the age of 25. The incidence rises more slowly for Caucasian women. However women over age 65 account for more than 25% of all cases of invasive cervical cancer.

The incidence of cervical cancer is highest among poor women and among women in developing countries. In the United States, the death rates from cervical cancer are higher among Hispanic, Native American, and African American women than among Caucasian women. These groups of women are much less likely to receive regular Pap tests. Therefore, their cervical cancers usually are diagnosed at a much later stage, after the cancer has spread to other parts of the body.

Causes and symptoms Human papillomavirus Infection with the common human papillomavirus (HPV) is a cause of approximately 90% of all cervical cancers. There are more than 80 types of HPV. About 30 of these types can be transmitted sexually, including those that cause genital warts (papillomas). About half of the sexually transmitted HPVs are associated with cervical cancer. These "high-risk" HPVs produce a protein that can cause cervical epithelial cells to grow uncontrollably. The virus makes a second protein that interferes with tumor suppressors that are produced by the human immune system. The HPV-16 strain is thought to be a cause of about 50% of cervical cancers.

More than six million women in the United States have persistent HPV infections, for which there are no cure. Nevertheless, most women with HPV do not develop cervical cancer.

Stage 0: Carcinoma in situ; non-invasive cancer that is confined to the layer of cells lining the cervix.
Stage I: Cancer that has spread into the connective tissue of the cervix but is confined to the uterus.
Stage IA: Very small cancerous area that is visible only with a microscope.
Stage IA1: Invasion area is less than 3 mm (0.13 in) deep and 7 mm (0.33 in) wide.
Stage IA2: Invasion area is 3-5 mm (0.13-0.2 in) deep and less than 7 mm (0.33 in) wide.
Stage IB: Cancer can be seen without a microscope or is deeper than 5 mm (0.2 in) or wider than 7 mm (0.33 in).
Stage IB1: Cancer is no larger than 4 cm (1.6 in).
Stage IB2: Stage IB cancer is larger than 4 cm (1.6 in).
Stage II: Cancer has spread from the cervix but is confined to the pelvic region.
Stage IIA: Cancer has spread to the upper region of the vagina, but not to the lower one-third of the vagina.
Stage IIB: Cancer has spread to the parametrial tissue adjacent to the cervix.
Stage III: Cancer has spread to the lower one-third of the vagina or to the wall of the pelvis and may be blocking the ureters.
Stage IIIA: Cancer has spread to the lower vagina but not to the pelvic wall.
Stage IIIB: Cancer has spread to the pelvic wall and/or is blocking the flow of urine through the ureters to the bladder.
Stage IV: Cancer has spread to other parts of the body.
Stage IVA: Cancer has spread to the bladder or rectum.
Stage IVB: Cancer has spread to distant organs such as the lungs.