The part next to the vagina is the .exocervix (or ectocervix). .The 2 main types of cells covering the cervix are .squamous .cells (on the exocervix) .and .glandular .cells (on the endocervix). The place where these 2 cell types meet is called the .transformation zone. Most cervical cancers start in the transformation zone (Cancer.org. What is Cervical Cancer, 2012).
The American Cancer Society estimates that more than 12,000 women develop cervical cancer each year in the United States and about 4,200 die from it. Worldwide, it continues to be the second most common type of cancer in women (after breast cancer). Each year, about 500,000 women are diagnosed with cervical cancer and approximately 250,000 die from it (Labtestsonline: Cervical Cancer, 2012).
Most cervical cancers begin in the cells lining the cervix. These cells do not suddenly change into cancer. Instead, the normal cells of the cervix first gradually develop pre-cancerous changes that turn into cancer. Doctors use several terms to describe these pre-cancerous changes, including cervical intraepithelial neoplasia (CIN), squamous intraepithelial lesion (SIL), and dysplasia. .There are 2 main types of cervical cancers: .squamous cell carcinoma .and .adenocarcinoma. About 80% to 90% of cervical cancers are squamous cell carcinomas. These cancers are from the squamous cells that cover the surface of the exocervix. Under the microscope, this type of cancer is made up of cells that are like squamous cells. Squamous cell carcinomas most often begin where the exocervix joins the endocervix (Cancer.org, 2012).
Most of the other cervical cancers are adenocarcinomas. Cervical adenocarcinomas seem to have becoming more common in the past 20 to 30 years. Cervical adenocarcinoma develops from the mucus-producing gland cells of the endocervix. Less commonly, cervical cancers have features of both squamous cell carcinomas and adenocarcinomas.