Cancer Types - Cervical Cancer
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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.
Precancerous conditions of the cervix are identified as cells that look 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. These cells are the flat cells found on the surface (of the cervix)
- Intraepithelial. This means that the abnormal cells are present only in the surface layer of cells
- Lesion. This refers to an area of abnormal tissue
Research has shown that chlamydia, the most common sexually transmitted disease in the U.S., may increase a woman's risk of developing cervical cancer. In the study, published in the Journal of the American Medical Association, women who showed signs of any type of chlamydial infection in their blood were two-and-a-half times more likely to develop cervical cancer, when compared to women with no sign of infection. Although the reason for this increased risk is still under investigation, researchers speculate that immune system cells that are activated at chlamydia infection sites may damage normal cells.
According to the National Cancer Institute, changes in these cells can be divided into two categories:
- Low-grade SIL. This 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 changes may also be called mild dysplasia or cervical intraepithelial neoplasia 1 (CIN 1).
- High-grade SIL. This means there are a large number of precancerous cells, and, like low-grade SIL, these changes involve only cells on the surface of the cervix. The cells often do not become cancerous for many months, perhaps years, but without treament, become cancer.
High-grade lesions may also be called moderate or severe dysplasia, CIN 2 or 3, or carcinoma in situ.
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 younger than the age of 50. 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.
The mortality rates for cervical cancer have declined sharply as Pap screenings have become more prevalent. According to the American Cancer Society about 12,170 cases of invasive cervical cancer will be diagnosed in the U.S. during 2012. Some researchers estimate that noninvasive cervical cancer (also referred to as "carcinoma in situ") is nearly four times more common than invasive cervical cancer.
A risk factor is anything that may increase a person's chance of developing a disease. It may be an activity, such as smoking, diet, family history, or many other things. Different diseases, including cancers, have different risk factors.
Although these factors can increase a person's risk, they do not necessarily cause the disease. Some people with one or more risk factors never develop cancer, while others develop cancer and have no known risk factors.
But, knowing your risk factors to any disease can help to guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.
The following have been suggested as risk factors for cervical cancer:
- Infection with the human papillomavirus (HPV). HPV is the cause of nearly all cervical cancers. Infection with HPV is most often the result of unprotected sex.
- Not getting regular Pap tests. Cervical cancer is more common in women who don't have regular Pap tests. Pap tests help doctors find abnormal cells. These cells can then be removed, which usually prevents cervical cancer.
- Infection with the human immunodeficiency virus (HIV) or other conditions that weaken the immune system. HIV is the precursor to AIDS and can increase your risk of cervical cancer. Taking certain medications that suppress the immune system also increases the risk of cervical cancer.
- Smoking. Women who smoke are nearly twice as likely as nonsmokers to have cervical cancer.
- Diet. Women with diets low in fruits and vegetables and those who are overweight are at increased risk for cervical cancer.
- Chlamydia infection. Some studies have seen a higher risk of cervical cancer in women whose blood test results show evidence of past or current chlamydia infection when compared with women who have normal test results. Chlamydia is spread by sexual contact.
- Using birth control pills for a long time. Using birth control pills for five or more years may slightly increase the risk of cervical cancer, but the risk decreases when women stop using birth control pills.
- Having many children. Studies suggest that giving birth to three or more children may slightly increase the risk of cervical cancer in women with HPV infections.
- Having sexual intercourse before the age of 18
- Having many sexual partners, and having partners who have had many partners themselves
- First full-term pregnancy at a young age. Women who were younger than 17 years when they had their first full-term pregnancy are almost two times more likely to get cervical cancer later in life than women who waited until they were 25 years or older to get pregnant.
- Poverty. Many low income women do not have access to adequate health care services, including Pap tests. So they are not screened or treated for cervical pre-cancers.
- Family history of cervical cancer. This cancer may run in some families. A woman's chance of developing it are two to three times higher if her mother or sister had cervical cancer than if no one in her family had it.
- Diethylstilbestrol (DES). DES is a drug that was used to prevent miscarriage between 1940 and 1971. Women whose mothers took DES while pregnant with them develop this cancer more than would normally be expected. The risk seems to be highest in women whose mothers took the drug during their first 16 weeks of pregnancy. (The FDA stopped the use of DES during pregnancy in 1971.)
Early detection of cervical problems is the best way to prevent cervical cancer. Routine, annual pelvic exams 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 exams and Pap tests are used to determine if there are cervical problems. Women who are age 21 or older should have regular checkups, including a pelvic exam and Pap test.
According to the National Institutes of Health:
A pelvic exam and Pap test allow the doctor 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 doctor'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 approved:
- Gardasil protects against four types of the HPV virus--the two types of viruses that cause most cervical cancers, and the two that cause 90 percent of genital warts. It protects against other cancers caused by HPV, too, such as cancers and precancers of the vagina, vulva and anus.
- Cervarix protects against the two types of the HPV virus that cause most cervical cancers. It protects against anal cancers, too.
These vaccines can only be used to prevent certain types of HPV infection before a person is infected. They cannot be used to treat an existing HPV infection.
Both vaccines are administered as a series of three injections over a six-month period. To be most effective, one of the vaccines should be given before a person becomes sexually active.
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 doctor for diagnosis.
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 so it can be examined under a microscope.
- 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 detects the presence of cervical HPV infection. 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 cervical tissue for further examination. This procedure requires the use of general anesthesia.
Specific treatment for cervical cancer will be determined by your doctor 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:
- Surgery, including:
- 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.
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