The cervix is the lower, narrow part of the uterus (womb) located between the bladder and the rectum. It forms a canal that opens into the vagina, which leads to the outside of the body.
What is cancer of the cervix?
If abnormal cells on the surface of the cervix spread deeper into the cervix, or to other tissues or organs, the disease is then called cervical cancer, or invasive cervical cancer. Cervical cancer occurs most often in women over the age of 40. It is different from cancer that begins in other parts of the uterus and requires different treatment. Most cervical cancers are squamous cell carcinomas and adenocarcinomas.
Early cervical cancer may not show noticeable signs or symptoms, so yearly check-ups with your physician are important, including a pap smear to check for abnormal cells. The mortality rates for cervical cancer have declined sharply as Pap screenings have become more prevalent. Some researchers estimate that noninvasive cervical cancer (also referred to as "carcinoma in situ") is nearly four times more common than invasive cervical cancer.
What are precancerous conditions of the cervix?
Precancerous conditions of the cervix are identified as cells that appear to be abnormal, but are not cancerous at the present time. However, the appearance of these abnormal cells may be the first evidence of cancer that develops years later.
Precancerous changes of the cervix usually do not cause pain and, in general, do not cause any symptoms. They are detected with a pelvic exam or a Pap test.
Squamous intraepithelial lesions (SIL) is a term that refers to abnormal changes in the cells on the surface of the cervix.
- squamous - cells are the flat cells found on the surface (of the cervix)
- intraepithelial - means that the abnormal cells are present only in the surface layer of cells
- lesion - refers to an area of abnormal tissue
According to the National Cancer Institute (NCI), changes in these cells can be divided into two categories:
- Low-grade SIL - refers to early changes in the size, shape, and number of cells that form the surface of the cervix. They may go away on their own, or, with time, may grow larger or become more abnormal, forming a high-grade lesion. These precancerous low-grade lesions may also be called mild dysplasia or cervical intraepithelial neoplasia 1 (CIN 1). These early changes most often occur in women between the ages of 25 and 35, but can appear at any age.
- High-grade SIL - means there are a large number of precancerous cells, and, like low-grade SIL, these precancerous changes involve only cells on the surface of the cervix. The cells often do not become cancerous for many months, perhaps years. High-grade lesions may also be called moderate or severe dysplasia, CIN 2 or 3, or carcinoma in situ. They develop most often in women between the ages of 30 and 40, but can occur at any age.
Risk Factors for Cervical Cancer
The following have been suggested as risk factors for cervical cancer:
- Infection with the human papillomavirus (HPV) - Infection with HPV is most often the result of unprotected sex.
- Infection with the human immunodeficiency virus (HIV) or other condition that weakens the immune system - HIV is the precursor to AIDS.
- Smoking - Women who smoke are nearly twice as likely as nonsmokers to have cervical cancer.
- Age - The risk of cancer of the cervix increases between the late teens and mid-30s. However, cervical cancer can occur at any age.
- Having sexual intercourse before the age of 18
- Having many sexual partners, and having partners who have had sexual intercourse at a young age and/or have had many partners themselves
Prevention of Cervical Cancer
Early detection of cervical problems is the best way to prevent cervical cancer. Routine, annual pelvic examinations and Pap tests can detect precancerous conditions that often can be treated before cancer develops. Invasive cancer that does occur would likely be found at an earlier stage. Pelvic examinations and Pap tests are the methods used to determine if there are cervical problems. Women who are or have been sexually active, or are age 18 or older, should have regular checkups, including a pelvic exam and Pap test.
According to the National Institutes of Health (NIH):
A pelvic exam and Pap test allow the physician to detect abnormal changes in the cervix. If an infection is present, it is treated and the Pap test is repeated at a later time. If the exam or Pap test suggests something other than an infection, a repeated Pap test and other tests are performed to determine the problem.
Women who have had a hysterectomy (surgery to remove the uterus, including the cervix) should ask their physician's advice about having pelvic exams and Pap tests.
Because certain strains of HPV have been found to cause most cases of cervical cancer, research efforts have focused on developing a vaccine against HPV. Two HPV vaccines have been developed, and clinical trials of these vaccines have been successful.
One of the vaccines, Gardasil®, was approved by the US Food and Drug Administration in 2006 and can protect women from HPV infections. It protects against four types of the HPV virus, including the two viruses that cause 90 percent of genital warts. Gardasil can only be used to prevent HPV infection before an abnormal pap test develops.
There is new evidence that Gardasil may also help protect against changes that can lead to vaginal, vulvar, and anal cancers.
Gardasil is administered as a series of three injections over a six month period. Recommendations for giving this vaccine are still being discussed but many professionals feel the vaccine should be given to girls before they become sexually active.
Symptoms of Cervical Cancer
Symptoms of cervical cancer usually do not appear until abnormal cervical cells become cancerous and invade nearby tissue.
- The most common symptom is abnormal bleeding, which may:
- start and stop between regular menstrual periods.
- occur after sexual intercourse, douching, or a pelvic exam.
- Other symptoms may include:
- heavier menstrual bleeding, which may last longer than usual
- bleeding after menopause
- increased vaginal discharge
- pain during intercourse
The symptoms of cervical cancer may resemble other conditions or medical problems. Consult a physician for diagnosis.
Diagnosis for Cervical Cancer
When cervical problems are found during a pelvic examination, or abnormal cells are found through a Pap test, a cervical biopsy may be performed.
There are several types of cervical biopsies that may be used to diagnose cervical cancer, and some of these procedures that can completely remove areas of abnormal tissue may also be used for treatment of precancerous lesions. Some biopsy procedures only require local anesthesia, while others require a general anesthesia. Several types of cervical biopsies include:
loop electrosurgical excision procedure (LEEP) - a procedure which uses an electric wire loop to obtain a piece of tissue.
- colposcopy - a procedure which uses an instrument with magnifying lenses, called a colposcope, to examine the cervix for abnormalities. If abnormal tissue is found, a biopsy is usually performed (colposcopic biopsy).
- endocervical curettage (ECC) - a procedure which uses a narrow instrument called a curette to scrape the lining of the endocervical canal. This type of biopsy is usually completed along with the colposcopic biopsy.
- cone biopsy (Also called conization.) - a biopsy in which a larger cone-shaped piece of tissue is removed from the cervix by using the loop electrosurgical excision procedure or the cold knife cone biopsy procedure. The cone biopsy procedure may be used as a treatment for precancerous lesions and early cancers.
- HPV DNA test - a test that examines the DNA of cervical cells. The cells are collected as they are for a regular Pap test, but it is not a replacement for a Pap test. The HPV DNA test may be used as a screening test for women over 30 or for women with slightly abnormal Pap test results to determine if further testing or treatment is required.
- cold knife cone biopsy - a procedure in which a laser or a surgical scalpel is used to remove a piece of tissue. This procedure requires the use of general anesthesia.
Treatment for Cervical Cancer
Specific treatment for cervical cancer will be determined by your physician based on:
- your overall health and medical history
- extent of the disease
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment may include:
- cryosurgery - use of liquid nitrogen, or a probe that is very cold, to freeze and kill cancer cells.
- laser surgery - use of a powerful beam of light, which can be directed to specific parts of the body without making a large incision, to destroy abnormal cells.
- hysterectomy - surgery to remove the uterus, including the cervix. In some cases, a hysterectomy may be required, particularly if abnormal cells are found inside the opening of the cervix.
- Radiation therapy
LEEP or conization may also be used to remove abnormal tissue.