Cervical intraepithelial neoplasia (CIN), or cervical dysplasia, can develop on the cervical surface as women age. CIN is an accumulation of new cells into a mass called a neoplasm.
Neoplasms are often harmless, but some can become malignant in a process called transformation. Unlike many other cancers, the progression of normal cervical cells to CIN and finally to cancer is slow. This provides a wide window of opportunity for early detection and treatment, which vastly improves outcome.
The Pap test, HPV testing, and many other techniques are used to screen for cervical cancer. These can detect CIN as well as cancer. The tests help physicians classify the type of carcinoma (for example, adenocarcinoma, squamous cell, small cell) based on which types of cells are involved.
Sometimes physical exams can detect cervical cancer, but most often these are only effective for late-stage tumors. Physicians may be able to feel cell masses in the cervix, rectum, or vagina. Tumors can be visualized using ultrasound or other imaging methods.
Most cases of CIN or cancer are detected following screening with a Pap test (also called a Pap smear or cervical smear). In this procedure, physicians scrape cells from the surface of the cervix with either a spatula, brush, or plastic broom. These cells are examined under a microscope for changes characteristic of cancer.
For the liquid-based Pap test, the cells are first rinsed in a solution before being mounted onto a slide for microscopy. Women 30 years of age or older may also be tested with the Hybrid Capture II HPV test in conjunction with a Pap smear. The HPV test detects HPV DNA in samples taken from the cervix or other genitourinary areas.
Doctors often use a procedure called a colposcopy to examine the cervix and look for any abnormal cell masses. To do this, a colposcope is inserted into the vagina and used to illuminate and magnify the cervical surface.
Biopsies are used to confirm that cervical cells have turned cancerous. A biopsy is the removal of cells from an organ or tissue. They can be performed in several ways. The colposcope used during a colposcopy can be fitted to remove cervical cells. Conization is a process by which a laser is used to remove a cone-shaped area of tissue. It removes several cellular layers, and is most often used in cases of suspected adenocarcinoma.
In the loop electrical excision procedure, cells are removed by scraping the cervix with an electrified wire loop. A punch biopsy uses a sharp, hollow device to pinch off cervical cells, and the endocervical curettage technique uses a spoon-shaped instrument (called a curette) or brush.
Overview of Staging Cervical Cancer
Staging helps physicians design a treatment strategy. It assesses whether CIN or cancer is present and whether cancerous cells have spread to other regions of the body. The same procedures used for diagnosis – colposcopy, endocervical curettage, and conization – are also used for staging.
Different procedures are used to examine other organs that may be involved: a hysteroscopy allows visualization of the walls of the uterus; cystoscopy, bladder. A proctoscopy can detect cancerous cells in the rectum and colon.
Physicians also use imaging techniques to help stage the cancer. Intravenous (IV) urography uses dyes and x-rays to visualize the kidneys and bladder. X-rays of bone and lung can detect masses in these organs. Computerized tomography (CT, computed tomography) scans are used to find cancer that has spread to the liver, lungs, lymph nodes, or other organs.
Magnetic resonance imaging (MRI) uses large magnets to form pictures of organs on a computer monitor. Positron emission tomography (PET) scans take advantage of the fact that cancer cells need a large amount of glucose. They can highlight tumor masses that have progressed beyond stage II.
Stages of Cervical Cancer
Cervical cancer that is non-invasive, or restricted to the surface layer of the cervix, is called carcinoma in situ. This is termed stage 0 and not considered a tumor. Invasive cervical cancer is placed into one of four stages:
- Stage I: the cancer has penetrated into several layers of the cervix. The extent of this invasion determines the substage, IA, IA2, IB1, or IB2.
- Stage II: cancer has spread beyond cervix. In stage IIA, the upper two-thirds of the vagina are involved. In stage IIB, the pelvic region, but not pelvic wall, is affected.
- Stage III: the malignancy affects the lower third of the vagina (stage IIIA), or the pelvic wall and/or blocks urination and causes kidney dysfunction (stage IIIB).
- Stage IV: the cancer has spread to the bladder or rectum (stage IVA) or to outside the pelvic region to distant sites (stage IVB).