What is cervical cancer?
Cervical cancer is cancer that starts in the cervix, the narrow opening into the uterus from the vagina. The normal “ectocervix” (the portion of the uterus extending into the vagina) is a healthy pink color and is covered with flat, thin cells called squamous cells. The “endocervix” or cervical canal is made up of another kind of cell called columnar cells. The area where these cells meet is called the “transformation zone” (T-zone) and is the most likely location for abnormal or precancerous cells to develop.
Most cervical cancers (80 to 90 percent) are squamous cell cancers. Adenocarcinoma is the second most common type of cervical cancer, accounting for the remaining 10 to 20 percent of cases. Adenocarcinoma develops from the glands that produce mucus in the endocervix. While less common than squamous cell carcinoma, the incidence of adenocarcinoma is on the rise, particularly in younger women.
More than 13,000 women in the United States will be diagnosed with cervical cancer each year, and more than 4,000 of women will die. Cervical cancer is the fourth most common type of cancer for women worldwide, but because it develops over time, it is also one of the most preventable types of cancer. Deaths from cervical cancer in the United States continue to decline by approximately 2 percent a year. This decline is primarily due to the widespread use of the Pap test to detect cervical abnormalities and allow for early treatment. Most women who have abnormal cervical cell changes that progress to cervical cancer have never had a Pap test or have not had one in the previous three to five years.
Cervical cancer tends to occur during midlife. It is most frequently diagnosed in women between the ages of 35 and 44. It rarely affects women under age 20, and more than 15 percent of diagnoses are made in women older than 65. But in women over 65, cancer typically occurs in women who were not receiving regular screening.
What causes cervical cancer?
Human papillomavirus (HPV) is found in about 99% of cervical cancers. There are over 100 different types of HPV, most of which are considered low-risk and do not cause cervical cancer. High-risk HPV types may cause cervical cell abnormalities or cancer. More than 70 percent of cervical cancer cases can be attributed to two types of the virus, HPV-16 and HPV-18 often referred to as high-risk HPV types.
HPV is estimated to be the most common sexually transmitted infection in the United States. In fact, by age 50 approximately 80% of women have been infected with some type of HPV. The majority of women infected with the HPV virus do NOT develop cervical cancer. For most women the HPV infection does not last long; 90% of HPV infections resolve on their own within 2 years. A small number of women do not clear the HPV virus and are considered to have “persistent infection. A woman with a persistent HPV infection is at greater risk of developing cervical cell abnormalities and cancer than a woman whose infection resolves on its own. Certain types of this virus are able to transform normal cervical cells into abnormal ones. In a small number of cases and usually over a long period of time (from several years to several decades), some of these abnormal cells may then develop into cervical cancer.
Symptoms of Cervical Cancer
Precancerous cervical cell changes and early cancers of the cervix generally do not cause symptoms. For this reason, regular screening through Pap and HPV tests can help catch precancerous cell changes early and prevent the development of cervical cancer.
Possible symptoms of the more advanced disease may include abnormal or irregular vaginal bleeding, pain during sex, or vaginal discharge. Notify your healthcare provider if you experience:
- Abnormal bleeding, such as
- Bleeding between regular menstrual periods
- Bleeding after sexual intercourse
- Bleeding after douching
- Bleeding after a pelvic exam
- Bleeding after menopause
- 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
These symptoms could also be signs of other health problems, not related to cervical cancer. If you experience any of the symptoms above, talk to a healthcare provider.
Two tests help prevent cervical cancer or find it early:
- The Pap test (or Pap smear) looks for precancers, which are cell changes on the cervix that might become cervical cancer if they are not treated appropriately.
- The human papillomavirus (HPV) test looks for the virus that can cause these cell changes.
You should get your first Pap test at age 21. If your test result is normal, you can wait three years for your next test.
If you’re 30 years old or older, you have three options:
- You can continue getting a Pap test only. If your test result is normal, you can wait three years for your next test.
- You can get an HPV test only. If your test result is normal, you can wait five years for your next test.
- You can get both an HPV and Pap test together. If your test results are normal, you can wait five years for your next tests.
The HPV vaccine protects against the types of HPV that most often cause cervical, vaginal, and vulvar cancers. HPV can also cause cancers of the penis in men, and anal and head and neck cancers in both men and women.
The HPV vaccine is recommended for boys and girls who are 11 to 12 years old but can be given as early as age 9 and until age 26