By John Messmer
Science has sought the “cause” of cancer for decades, and in the case of cervical cancer, the cause has been found. The cervix is the opening to the womb that is situated at the upper end of the vagina. Until recently the best approach to cervical cancer was to detect it early with a Pap test performed during a gynecologic examination. While the occurrence of advanced cervical cancer has dropped through widespread use of the Pap test, there are many women in the United States and millions worldwide who do not get or have access to Pap tests. This year in the United States, about 12,000 women will be diagnosed with cervical cancer. Almost 4,000 will die of the disease which is easily detectable and easily cured, if found early.
Cervical Cancer Awareness 2009 identifies prevention as a key component in the fight against cervical cancer. We now know cervical cancer is caused by the human papilloma virus (HPV). There are many strains of HPV – some cause common warts, but four strains are responsible for most cervical cancer and some others cause genital warts. Strains that infect the hands and feet do not infect the vagina or cervix, and vice versa. HPV is contracted from other people. In the case of cervical HPV infections, it is contracted by sexual intercourse.
At least half of all sexually active people become infected with at least one strain of HPV. Fortunately, most of these are defeated by a healthy immune system and never cause a problem. Some, however, go on to cause changes that lead to cervical cancer.
Since cervical cancer is sexually transmitted, the earlier sexual activity begins and the more sex partners a woman has, the greater her risk. Condoms do not reduce risk as they do for other sexually transmitted diseases. Lesbians do not have a lower risk of cervical cancer than heterosexual women and also should be examined annually. Smoking and secondhand exposure increase the risk of cervical cancer, probably by tobacco’s deleterious effects on the immune system.
To reduce the risk of HPV infection in the first place, a vaccine has been approved by the Food and Drug Administration (FDA). The HPV vaccine provides protection against the two most common strains of cancer-causing HPV and two strains that cause genital warts. The three-dose series reduces the risk of cervical cancer by 70 percent and genital warts by 90 percent. Annual Pap tests are still needed, but the chance of an abnormal result is greatly reduced after the vaccine.
The recommendation for vaccination is girls between age 9 and 26 years old, ideally before sexual activity, but not limited to those without prior sexual contact. Some argue that abstinence and limiting exposure to one sexual partner is better than a vaccine. Still, it is a risk for parents to withhold vaccination and hope their daughter will follow this restriction. Vaccines are like seatbelts – it might not be needed, but if it is, it’s best to have it ahead of time.
One day, cervical cancer might be totally preventable. Until then, the risk of invasive cancer of the cervix can be reduced by vaccination of appropriate women, delay in onset of sexual activity and limiting partners, avoidance of tobacco and annual Pap exams.
More information on cervical cancer can be found at http://www.cdc.gov/cancer/cervical/ on the Web or by visiting Penn State Milton S. Hershey Medical Center Health Information Library online.
John Messmer is associate professor of family and community medicine at Penn State College of Medicine and a staff physician at Penn State Hershey Medical Center.