Page modified at: 23/11/2009
What is Cervical Cancer?
Cervical cancer is a cancer of the cervix — the lower, narrow portion of the uterus that joins with the vaginal canal. It is the second-leading cause of cancer among women worldwide, although it is not as common in the U.S. This is because cervical cancer is highly preventable — due in large part to routine pap testing. The majority of cervical cancers are linked to human papillomavirus (HPV), but other risk factors may also contribute.
About Cervical Cancer
Cervical cancer develops from abnormal cells in the cervical lining. Routine pap testing can identify these cells before they become invasive, making cervical cancer one of the most preventable cancers.
Protecting Against Cervical Cancer
In addition to getting regular pap tests, there's more you can do to safeguard yourself against other risks associated with cervical cancer.
When detected early, cervical cancer is highly treatable. The best way to protect yourself is to have regular pap tests, and catch precancerous and cancerous cells before they become serious. The widespread use of pap testing is thought to be the main reason for the ongoing decline in cervical cancer deaths in the U.S. and other developed countries.
Types of cervical cancer
The type of cervical cancer a woman may develop depends on which cells of the cervix — the lower, narrow portion of the uterus that joins with the vaginal canal — are affected. There are two types of cells, known as squamous cells and glandular cells, that may develop into squamous cell carcinoma (cancer of the squamous cells) or adenocarcinoma (cancer of the glandular cells). Squamous cell carcinoma can be thought of as similar to skin cancer because it begins on the surface of the extocervix,1,2 a part of the cervix that is closer to the opening of the vaginal canal. Adenocarcinoma begins further inside the uterus, in the mucus-producing gland cells of the endocervix.
Squamous cell carcinoma
Squamous cells are flat cells on the outer surface of the cervix. They are like the cells you find on the outer layer of your skin. When these cells start to grow abnormally, it is the beginning of squamous cell cancer, or carcinoma. This is the most common form of cervical cancer. The good news is that this type of cancer is generally slow growing. Squamous cell cancer can take three to five years to fully develop. That's why routine pap testing is a good idea to catch changes before they become cancerous.
The passageway leading from the cervix into the uterus is lined with gland cells that produce mucus; abnormal growth of these cells can lead to adenocarcinoma. The number of women developing adenocarcinoma is on the rise. Reasons for this increase are unclear; it may have to do with the difficulty of finding abnormal cells that are further inside the uterus than squamous cells. The rise of adenocarcinoma serves as a reminder that regular pap testing is an important component of your long-term cervical health.
How does cervical cancer progress?
Cervical cancer usually takes several years to develop, as cells change from "normal" to "precancerous" (dysplastic). Precancerous cells are abnormal cells on the inner surface of the uterus; they have not broken through the lining of the uterus to become invasive. With regular exams, a pap test may detect precancerous changes, which can be treated before cancer develops.
Precancerous cells are abnormal, but they affect only the surface of the cervical tissue. Over time, precancerous cervical cells can invade deeper into the cervix and grow out of control. They can spread into the tissue near the cervix, or travel to other parts of the body through the blood or lymph fluid. It is more difficult to treat cervical cancer once it spreads to other tissue.
What are the symptoms of cervical cancer?
Generally, precancerous changes and early cervical cancer won't necessarily result in clear symptoms. If symptoms do occur, they may include abnormal bleeding, such as:
Bleeding between monthly periods Bleeding after sex, after douching, or after a pelvic exam
Symptoms may also include:
Pelvic pain not related to your menstrual cycle Heavy or unusual discharge that may be watery, thick, and possibly have a foul odor Increased urinary frequency Pain during urination
Be sure to speak to your doctor if you have any of these symptoms.
Who gets cervical cancer?
Most cervical cancer cases are diagnosed between the ages of 35 and 55 years old. However, younger women who are sexually active and older women are also at risk. For this reason, the American Cancer Society recommends:
Regular pap tests for all women beginning 3 years after first having sex or no later than age 21 and continuing until at least age 70 Pap tests should be performed every 2 years and should use a liquid-based test Most cases of advanced cervical cancer are diagnosed in women who have not been getting routine pap tests.
The role of HPV
While there are many possible risk factors for cervical cancer, HPV (human papillomavirus) is linked to 99.7% of all squamous cell carcinomas and a large portion of adenocarcinomas.
About HPV and Cervical Cancer
Human papillomavirus, or HPV, is a group of over 100 virus types that are transmitted by skin-to-skin contact. Most strains of HPV will clear on their own. But a few "high-risk" strains, if persistent, may develop into cervical cancer, although this is rare. It's important to remember that not all high-risk strains are covered by the HPV vaccine. Routine pap testing, and HPV testing when recommended, is the best way to screen for cervical cancer.
Who gets HPV?
About 80% of sexually active women have contracted at least one strain of genital HPV by age 50.1 At any given time, approximately 20 million people in the U.S. will have HPV, and approximately 6.2 million are estimated to contract a form of HPV each year. Since HPV rarely produces noticeable symptoms, many people with HPV don't even know they have it.
Genital warts and cervical cancer
People often think of genital warts when they think of HPV, but many are not aware that genital warts are most often associated with low-risk strains of HPV. High-risk strains most often don't cause warts. So it's important not to confuse genital warts with your cervical cancer risk.
High- and low-risk HPV strains
There are over 100 different strains of HPV. The majority are considered to be "low-risk," meaning they are not associated with cervical cancer. In fact, most HPV infections will go away by themselves within 2 years. HPV strains are considered to be high-risk, and may over time lead to cervical cancer. Just two of these high-risk strains — HPV-16 and HPV-18 — have been shown to account for about 70% of cervical cancer cases.
The HPV vaccine
The HPV vaccine protects against two high-risk HPV strains: HPV-16 and HPV-18. These strains are responsible for about 70% of cervical cancer cases. However, not all high-risk strains are covered by the vaccine. That's why regular pap testing, and HPV testing when recommended, remains important whether or not you've had the HPV vaccine.
Testing for HPV
While high-risk HPV is known to cause the majority of cervical cancers a small amount of HPV infections actually become cervical cancer. In fact, most sexually active women will be exposed to HPV and the vast majority of these infections will clear on their own. At this time, there is no cure for HPV. If your doctor recommends an HPV test with your pap test, both can be taken from your ThinPrep pap test sample. However, for infections that persist, routine pap testing and HPV testing when recommended are the surest method for early detection.
Other Risk Factors for Cervical Cancer
Your sexual history, health history, and current lifestyle are all part of your cervical health. In addition to HPV, each of these factors can affect your risk for developing cervical cancer.
Your history and current lifestyle
Although HPV (human papillomavirus) is one of the main causes of cervical cancer, other factors may put you at risk for developing cervical cancer. Be sure that your doctor is aware if you have any of the following types of risk factors.
Sexual intercourse at an early age
Multiple sexual partners
Previous cancer diagnosis
Weakened immune system and/or HIV infection
Not getting regular pap tests
By minimizing these risk factors and having routine checkups and pap tests, you can ensure that you’re doing all you can to prevent cervical cancer.
Diagnosis and Treatment for Cervical Cancer
The key to protecting yourself from cervical cancer is early diagnosis and treatment. When caught early, nearly all cervical cancers are treatable. And the surest way to catch cervical cancer early is to get regular pap tests, and HPV tests when recommended.
Protecting Yourself Against Cervical Cancer
One of the most important things you can do to protect yourself against cervical cancer is to get routine pap tests, and HPV tests when recommended. There may also be things you can do to minimize your risk of getting cervical cancer, such as getting the HPV (human papillomavirus) vaccine if you are between the ages of 9 and 26.
Getting regular pap tests
The pap test is the most successful cervical cancer screening program. And remember, over 90% of pap test results come back as normal. In the event that your pap test comes back as abnormal, your doctor will recommend appropriate follow-up and possible treatment if necessary.
HPV test when recommended
If your pap test comes back as inconclusive or slightly abnormal then your doctor may recommend an HPV test. Likewise if you are age 30 or older an HPV test may be recommended with your pap test.
Continuing your annual exam
Your annual exam plays an important role in your cervical as well as your overall health. During your annual exam, your doctor checks many things, including your blood pressure, breasts, vagina, and other pelvic organs. Your doctor may also recommend testing for sexually transmitted diseases in addition to routine pap testing.
What if I have an abnormal pap smear result?
If your pap test shows abnormal cells, your doctor will discuss appropriate follow-up. In some cases, your doctor may simply recommend pap testing at more frequent intervals.
In other cases, your doctor may suggest colposcopy, a procedure that enables the doctor to examine the cervix — the lower, narrow portion of the uterus that joins with the vaginal canal — under magnification. If necessary, a biopsy, in which a small tissue sample is taken, may be performed.
Treating cervical cancer
Cervical cancer is a highly treatable condition. The choice of treatment is a decision made between a woman and her doctor, considering a number of factors such as the stage of cancer and the desire for future pregnancy. The treatment options for cervical cancer include surgery, radiation, and chemotherapy, given alone or in combination.
Surgical treatments allow for the removal of precancerous or cancerous cells; common procedures include:
LEEP — loop electrosurgical excision procedure (LEEP) uses electrical current passed through a thin loop-shaped wire to remove precancerous cells on the surface of the cervix. Conization — also called a cone biopsy, this procedure involves the removal of a cone-shaped piece of tissue from the cervix. Hysterectomy — is the removal of all or part of the uterus and cervix, and can be performed via an incision in the abdomen or the vagina.
Nonsurgical treatments can include:
Radiation therapy — uses high-energy X-rays or other radiation to kill or prevent cancer cells from growing.It can be given either from the outside (much as you would receive an X-ray) or from the inside (using various kinds of radioactive seeds, wires, or catheters). Chemotherapy — uses one or more drugs to kill cancer cells or stop them from growing.
- Dorland's illustrated medical dictionary. 29th ed. Philadelphia: W.B. Saunders; 2000. Endocervix; p. 625.
- American Cancer Society. What is Cervical Cancer? Available at: http://www.cancer.org/docroot/CRI/ content/CRI_2_4_1X_What_is_cervical_cancer_8.asp?rnav=cri. Accessed 12/09/07.
- American College of Obstetricians and Gynecologists Pamphlet. Cancer of the Cervix. Washington DC; 2004.
- American Cancer Society. Guidelines for Early Detection of Cancer. Available at: http://www.cancer.org/docroot/PED/ content/PED_2_3X_ACS_Cancer_Detection_Guidelines_36.asp?sitearea=PED. Accessed 3/14/08.