About Cervical cancer
The cervix is the lower, narrow part of the uterus (womb). It forms a canal that connects the body of the uterus to the vagina.
Cervical cancer originates in the lining of the cervix. The cancer does not form suddenly; rather, it takes years to develop. The process begins when abnormal (but not cancerous) cells slowly grow and spread more deeply into the cervix. This precancerous overgrowth of cells is called cervical dysplasia. Scientists believe that dysplasia is the first step in a slow process that can eventually lead to cancer.
Fifty years ago, cervical cancer was the leading cause of cancer death among American women. But thanks to the development of the Pap smear test – named after George Papanicolaou, who introduced the test in 1943 – the death rate from cervical cancer has since dropped by 74 percent.
What are the risk factors for cervical cancer?
The risk factor that far outweighs all others is infection with the human papilloma virus (HPV), which is sexually transmitted. HPV is actually a family of over 75 viruses, 13 of which are known to cause cervical cancer. Infection is extremely common, but many women never know they have HPV because the virus does not always produce symptoms. When it does, the main symptom is genital warts. Overall, HPV has been associated with 82 percent of all cases of cervical cancer.
Other risks for cervical cancer include factors that increase a woman’s risk of getting HPV, including: engaging in sexual intercourse starting at an early age; having multiple sexual partners; having sexual intercourse with someone who has had multiple partners; and having other sexually transmitted diseases, such as chlamydia or herpes.
Not having an annual pelvic exam with a Pap smear test is another major risk factor for cancer of the cervix. Fifty percent of all women who get invasive cervical cancer have never had a Pap smear, and 40 percent have not had one within five years of their diagnosis. Many health-care professionals recommend that all women have yearly Pap tests starting at age 18 or when they start having sexual intercourse.
Increasing age and smoking are also risk factors for cervical cancer (as they are with all cancers). In addition, certain minorities have higher cervical cancer death rates, including African Americans, Hispanics and Native Americans. Poor women are at greater risk for the disease, most likely because they cannot afford to get regular Pap tests.
Finally, infection with HIV (the virus that causes AIDS) is a risk factor for cervical cancer because being HIV-positive weakens a woman’s immune system, making her less able to fight the virus and early cancers.
Can anything be done to prevent cervical cancer?
Yes. Getting a yearly Pap-smear test, which can detect abnormal cells before they progress to cancer, greatly reduces a woman’s risk of cervical cancer. As mentioned above, 90 percent of all women who get invasive cervical cancer have not had a Pap smear within the last five years.
Other precautions women can take include: limiting the number of sexual partners; consistently using condoms to prevent transmission of sexual infections*; and quitting smoking.
*Condoms cannot prevent the spread of HPV, which is transmitted by skin-to-skin contact with any HPV-infected skin in the genital region. However, contracting other sexual infections makes a woman more susceptible to HPV, and condom use can prevent transmission of those infections.
What exactly is a Pap-smear test?
A Pap smear involves taking a sample of cells from the cervix. The doctor uses an instrument called a speculum to open the vagina. He or she then scrapes the surface of the cervix with a cotton swab, a brush, or a small wooden stick. The specimen is placed on a glass slide and sent to a medical laboratory to be examined under a microscope for the presence of infection, inflammation, or cancer.
Abnormal results are found in about 5–10 percent of cases. Most of the time, an abnormal test does not represent cancer but rather irritations or precancerous abnormalities that may correct themselves on their own.
How accurate are Pap-smear tests?
Although the Pap test is currently the best method of preventing and detecting cervical cancer, it is not fail-proof. Errors in both collection and inspection of the cervical smear frequently occur. In fact, false negatives (results that incorrectly indicate that no cancer is present) are relatively common. This is why women need to have a Pap test done annually.
Several new tests have recently been developed to improve the accuracy of Pap smear collection and inspection. One test, ThinPrep, provides a cleaner, clearer picture of cervical cells than the conventional Pap smear. Studies have shown that ThinPrep can reduce the rate of false negatives by as much as 30-40 percent.
Another new test, called Hybrid Capture, can be used in combination with a Pap test to clarify borderline results. The test detects the DNA of HPV. If HPV is found, a woman is considered at much higher risk for cervical cancer and can be closely monitored.
Two other new tests, PAPNET and AutoPap, use computer scanning systems to rescreen any Pap-smear slides deemed normal by lab workers. These tests have not proven to be significantly better than humans at re-examining slides.
What are the symptoms of cervical cancer?
Precancerous changes of the cervix and early cervical cancer generally do not cause any symptoms. This is why it’s so important to have regular pelvic exams and Pap tests. Symptoms do not usually appear until the cancer has spread to nearby tissue. At that point, the most common symptom is abnormal bleeding between regular menstrual periods or after sexual intercourse. Unusual vaginal discharge is another symptom.
What tests are used to confirm a diagnosis of cervical cancer?
If the results of a Pap smear suggest cancer, the following diagnostic tests may be done:
Colposcopy: The doctor examines the cervix through an instrument similar to a microscope, called a colposcope. The doctor may coat the cervix with an iodine solution that turns healthy cells brown and abnormal cells white or yellow (a Schiller test).
Biopsy: The doctor uses one of several methods to remove a sample of tissue for closer examination under a microscope. A biopsy is the only way to know for sure whether cancer is present.
If the biopsy reveals cancer, more tests will be done to find out how far the cancer has spread; for example, a cystoscopy to check if the cancer has spread to the bladder; a proctoscopy to check if the cancer has spread to the rectum; and a chest x-ray to check the lungs for cancer.
What are the stages of cervical cancer?
Stage 0, or “carcinoma in situ,” is the earliest stage of cervical cancer, in which abnormal cells are confined to the first layer of cervical cells and have not migrated to the deeper tissues of the cervix. If detected at Stage 0, the survival rate of cervical cancer is 100 percent.
In Stage I, the cancer has spread within the cervix but has not spread to nearby organs. Survival rates are still excellent at this stage, at about 85-90 percent.
In Stage II, the cancer has spread to nearby areas but is still confined to the pelvic area. Survival rates at this stage are about 60 percent.
Stage III is defined as cancer that has spread throughout the pelvic area and possibly to the lower part of the vagina. Cancerous cells may also have spread to the tubes that connect the kidneys to the bladder (the ureters). Survival rates are approximately 30 percent.
In Stage IV, cancer has spread to other parts of the body, either close to the cervix, such as the bladder or rectum, or to distant organs, such as the lungs. At stage IV, the survival rate is about 10 percent.
How is cervical cancer treated?
Treatment of cervical cancer depends on the stage as well as a woman’s age, overall health, and desire to have children.
To treat Stage 0, a doctor may use one of several types of surgery to either cut out the cancerous tissue or destroy it.
Conization: In this procedure, the doctor removes a cone-shaped piece of tissue where the abnormality is found.
Laser Surgery: A laser is used to destroy the abnormal area without damaging the surrounding healthy tissue.
LEEP: Loop electrosurgical excision procedure (LEEP) uses an electric current passed through a thin wire, which acts as a knife to remove a small piece of tissue.
Cryosurgery (freezing) or Cauterization (burning): This is also common methods of destroying the abnormal tissue.
For Stage I cervical cancer, treatment may involve a simple hysterectomy, in which only the uterus is removed; a radical hysterectomy, in which the uterus, the cervix, and the upper part of the vagina are removed along with lymph nodes from the pelvis (called pelvic lymph node dissection); or radiation therapy (the use of high-energy rays to kill cancer cells).
Stage II cancer can be treated with either radical hysterectomy with pelvic lymph node dissection or radiation therapy. For younger women, surgery may be a better option because it preserves ovarian function; radiation therapy does not. Sometimes chemotherapy (the use of cancer-killing drugs that circulate throughout the entire body) is also used.
For Stage III and Stage IV cervical cancer, treatment involves radiation therapy plus chemotherapy.
When cervical cancer comes back after earlier treatment (recurrent cancer), surgery known as pelvic exenteration may be used. In addition to all the organs and tissues removed in a radical hysterectomy with pelvic lymph node dissection, the bladder, vagina, rectum, and part of the colonmay also be removed.
Cervical Cancer Signs/Symptoms
- Abnormal vaginal discharge
- Unusual vaginal bleeding
- Pelvic pain
- Intercourse before age 18
- Multiple male sex partners
- Sexually transmitted infection with certain types of human papillomavirus
- Cigarette smoking
- Pelvic exam
- Pap test
- Radiation therapy
- Clinical trials
- Annual Pap test
- Sexual partner discretion