Cancer of the Cervix (Cervical Cancer)
The cervix is the lower part of the uterus, at the entrace (or exit from the baby’s point of view) to the womb. The cervix connects the body of the uterus to the vagina. The endocervix is the part of the cervix closest to the body of the uterus. Next to the vagina is the ectocervix. Most cervical cancers start where the endocervix and and ectocervix meet. Cancer of the cervix (also known as cervical cancer) begins in the the most superficial layer of cells of the cervix. Normal cervical cells 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. The Pap’s smear test is used to detect these early pre-cancerous conditions. There are two main types of cervical cancers: adenocarcinoma and squamous cell carcinoma. (Cervical cancers and cervical precancers are classified by their appearance under a microscope.) About 10% to 20% of cervical cancers are adenocarcinomas. Adenocarcinomas are becoming more common in women born in the last 20 to 30 years, we think due to synthetic hormone therapy in the mothers of these women. Cervical adenocarcinomas develop from the mucus-producing gland cells of the endocervix. The remaining 80% to 90% of cervical cancers are squamous cell carcinomas, composed of flat, thin cells that resemble the squamous cells that cover the surface of the endocervix. Squamous cell carcinomas most often begin where the ectocervix joins the endocervix. Less commonly, cervical cancers have features of both squamous cell carcinomas and adenocarcinomas. These are called adenosquamous carcinomas or mixed carcinomas. Not all women with pre-cancerous changes of the cervix will develop cancer. This process usually takes several years but sometimes can happen in less than a year. For most women, pre-cancerous cells will remain unchanged and go away without any treatment, however we have no way of knowing if this will happen in an individual case. If all of these precancers are treated, almost all cancers can be prevented.