Cancer of the cervix (the portion of the uterus that extends downward into the vagina) is the third leading cause of gynecologic cancer.
It is almost always caused by a sexually transmitted organism human papillomavirus (HPV). Cervical cancer typically develops over the long term from abnormal precancerous (before-cancer) cells on the surface of the cervix. Once cancer develops, the cells may spread (i.e. metastasize) to other organs.
Pap test also known as Pap smear.
A Pap test is a simple, quick office test in which a sample of cells from a woman's cervix is collected by swabbing the surface of the cervix and spreading the cells on a microscope slide or placed in a special solution. The cells are examined under a microscope in order to look for precancerous (before-cancer) or cancer cells.
Who to test and how often
Women should have Pap tests as part of an annual pelvic examination beginning at age 21 or three years following the onset of sexual activity. The risk of cervical cancer increases sharply during the first few years following the initiation of sexual activity. Some physicians begin screening women as soon as they become sexually active, but not before. High-risk factors for cervical cancer of the cervix include:
- cigarette smoking;
- a history of genital warts or other genital infection with the human papilloma virus (HPV);
- multiple sexual partners or a partner who has multiple sexual partners;
- the onset of sexual activity at a young age.
In 2009, the American College of Obstetricians and Gynecologists (ACOG) revised its recommendations regarding Pap testing. Instead of beginning at age 18 as previously recommended, the new recommendations advise beginning Pap smears at age 21. Further changes to the ACOG guidelines are:
- women younger than 30 years of age should have a Pap test every 2 years.
- women aged 30 years of age and older should have a Pap test every 2 years. After three normal Pap test results in a row, a woman in this age group may have Pap tests every 3 years if:
- she does not have a history of moderate or severe dysplasia;
- she is not infected with human immunodeficiency virus (HIV);
- her immune system is not weakened (for example, if she has had an organ transplant);
- she was not exposed to diethylstilbestrol (DES) before birth.
As it is rare to find a pre-cancerous or cancerous lesion of the cervix in women over the age of 65 who have repeatedly had normal Pap smears, many doctors decrease the frequency of Pap screening under these circumstances.
Women who have had a hysterectomy (surgery to remove the uterus, including the cervix) do not need Paps unless they have had a cancerous or pre-cancerous lesion of the genital tract. However, they should continue to have manual pelvic and rectal examinations by their doctors as a part of their periodic medical evaluations for reasons other than cancer of the cervix.
Benefits of early detection
There has been a 70% decrease in the death rate from cervical cancer, in large part because of judicious use of the Pap test. Benefits of the Pap test include:
- early identification and treatment of abnormal cells before they become cancerous.
- identification of cervical cancer at an early stage, thereby allowing optimum treatment before the cancer has metastasized.
A vaccine (Gardasil) has received U.S. FDA approval for use in young women between 9 and 26 years of age. Early vaccination will consistently protect against HPV types 6, 11, 16, and 18 unless the patient has already been infected by one of these viral types. HPV types 16 and 18 are known to be the two viral types most frequently associated with pre-cancerous and cancerous lesions of the cervix. Initial trials with the vaccine have shown that the HPV-16/18 vaccine is safe and induces a high degree of protection against HPV-16/18 infection. Gardasil is given in three injections over a six-month interval. The U.S. Centers for Disease Control and Prevention (CDC) recommends that girls 11-12 years of age receive the vaccine. It is also recommended for girls and women age 13 through 26 who have not yet been vaccinated or completed the vaccine series.
A newer vaccine (Cervarix) was approved by the FDA in October, 2009, for use in girls and young women ages 10-25 to help prevent cervical cancer. Cervarix targets two HPV strains, HPV 16 and HPV 18. A well-controlled study comparing Gardisil and Cervarix has yet to be conducted.