Cervical cancer begins in the lining of the cervix. Cervical cancers do not form suddenly. Normal cervical cells gradually develop precancerous changes that turn into cancer. Doctors use several terms to describe these precancerous changes, including cervical intraepithelial neoplasia (CIN),squamous intraepithelial lesion (SIL), and dysplasia.
Some women with precancerous changes of the cervix will develop cancer. This process usually takes several years, but sometimes it can happen in less than a year. For most women, precancerous cells will remain unchanged and go away without any treatment. But if these precancers are treated, almost all true cancers can be prevented.
Early cervical cancers and pre-cancers do not usually have symptoms. Symptoms begin when cancer becomes invasive and may include:
- Abnormal vaginal bleeding after intercourse, after menopause, and between menstrual periods, or having longer or heavier menstrual periods than usual.
- Unusual vaginal discharge which may include blood and occurs between menstrual periods or after menopause.
- Pain during intercourse.
It is important to talk to your doctor as soon as possible if you are experiencing any of these symptoms to determine the cause even if you are getting regular Pap tests. These symptoms can be caused by conditions other than cervical cancer.
(American Cancer Society, 2012)
Several risk factors increase your chance of developing cervical cancer. Women without any of these risk factors rarely develop cervical cancer. Although these risk factors increase the odds of developing cervical cancer, many women with these risks do not develop this disease. When a woman develops cervical cancer or precancerous changes, it is not possible to say with certainty that a particular risk factor was the cause.
Age. The average age of women newly diagnosed with cervical cancer is between 50 and 55 years. Although cervical cancer does affect young women, many older women do not realize that their risk of developing cervical cancer does not decrease as they age, therefore, it is important to continue having Pap tests.
Human papillomavirus infection. The most important risk factor for cervical cancer is infection by the human papillomavirus (HPV). HPVs are a group of more than 100 types of viruses called papillomaviruses because they can cause warts, or papillomas. Different HPV types are passed from person to person during sexual contact and can cause different types of warts to develop on the cervix or vagina that are not visible and cause no symptoms.
HPV infection can cause changes in cells of the cervix that can be detected by the Pap test. New tests can directly identify DNA from HPVs and identify the exact HPV type causing the infection. Many doctors now test for HPV if the Pap test result is only slightly abnormal. If a high-risk type of HPV is present, they will perform a colposcopy and consider further treatment.
Human immunodeficiency virus (HIV). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). Because this virus damages the body's immune system, it makes women more susceptible to HPV infections, which may increase the risk of cervical cancer. Scientists believe that the immune system is important in destroying cancer cells and slowing their growth and spread. In women infected with HIV, a cervical precancer might develop into an invasive cancer faster than it normally would.
Smoking. Smoking exposes the body to many cancer-causing chemicals that affect more than the lungs. These harmful substances are absorbed by the lungs and carried in the bloodstream throughout the body. Tobacco by-products have been found in the cervical mucus of women who smoke. Researchers believe that these substances damage the DNA of cells in the cervix and may contribute to the development of cervical cancer. Women who smoke are about twice as likely as nonsmokers to get cervical cancer.
Chlamydia. Chlamydia is a relatively common kind of bacteria that can infect the female reproductive system and is spread by sexual contact. Although infection may cause symptoms, many women do not know they are infected unless samples taken at the time of their Pap test are analyzed for this type of bacteria. Research has shown that women with chlamydia have a higher risk for developing cervical cancer. Long-term chlamydia infection is well known as a cause of pelvic inflammation, which can lead to infertility.
Diet. Women with poor diets may be at increased risk for cervical cancer. Diets low in fruits and vegetables are associated with an increased risk of cervical cancer and many other cancers.
Family history of cervical cancer. Recent studies suggest that women whose mother or sisters have had cervical cancer are more likely to develop the disease. Some researchers suspect this familial tendency is due to an inherited condition that makes some women less able than others to fight off HPV infection.
The most common form of cervical cancer starts with precancerous changes, and you can prevent most precancers of the cervix by avoiding risk factors, notably the human papillomavirus (HPV). Condoms may not protect against HPV infection. This is because HPV can be passed from person to person through any skin-to-skin contact with any HPV-infected area of the body, such as skin of the genital or anal area not covered by the condom. Even if there are no visible warts or other symptoms, a person with HPV can still pass on the virus to another person. HPV can be present for years with no symptoms.
It is still important to use condoms to protect against AIDS and other sexually transmitted diseases that are passed on through some body fluids. Refraining from smoking is another way to reduce the risk of cervical cancer and precancer.
An HPV vaccine has been recently approved by the FDA for girls as young as 9 years old. When combined with regular Pap Smears the vaccine could make most types of cervical cancer preventable. HPV vaccine is an inactivated vaccine (not live) which protects against 4 major types of HPV. These include 2 types that cause about 70% of cervical cancer and 2 types that cause about 90% of genital warts. Protection is expected to be long-lasting. But vaccinated women still need cervical cancer screening because the vaccine does not protect against all HPV types that cause cervical cancer. In the District of Columbia, legislation was passed in 2007 requiring all female students enrolling in grade 6 for the first time at a school in the District to be vaccinated against HPV or to obtain a waiver. For more information go to www.dc.gov.
Detecting Precancerous Changes
The second way to prevent invasive cancer is to have screening (including a Pap test) to detect precancers. Most invasive cervical cancers are found in women who have not had regular Pap tests.
The American Cancer Society recommends the following guidelines for early detection:
- All women should begin cervical cancer screening about three years after they begin having vaginal intercourse, but no later than when they are 21 years old. Screening should be done every year with the regular Pap test, or every two years using the liquid-based Pap test.
- Beginning at age 30, women who have had three normal Pap test results in a row may get screened every two to three years with either the conventional (regular) or liquid-based Pap test. Women who have certain risk factors such as diethylstilbestrol (DES) exposure before birth, HIV infection, or a weakened immune system due to organ transplant, chemotherapy, or chronic steroid use should continue to be screened annually.
- Another reasonable option for women over 30 is to get screened every three years (but not more frequently) with either the conventional or liquid-based Pap test, plus the HPV DNA test.
- Women 70 years of age or older who have had three or more normal Pap tests in a row and no abnormal Pap test results in the last ten years may choose to stop having cervical cancer screening. Women with a history of cervical cancer, DES exposure before birth, HIV infection, or a weakened immune system should continue to have screening as long as they are in good health.
- Women who have had a total hysterectomy (removal of the uterus and cervix) may also choose to stop having cervical cancer screening, unless the surgery was done as a treatment for cervical cancer or precancer. Women who have had a hysterectomy without removal of the cervix should continue to follow the guidelines above.