Nearly every person who develops cervical cancer did so as a result of contracting one of around 15 types of human papillomavirus, or HPV, a sexually transmitted disease. There are actually more than 150 types of HPV, though most of them are not associated with cancer; a substantial portion of sexually active people have one form or another of the infection, but because most strains cause no symptoms, the exact percentage is hard to determine.
Both HPV and cervical cancer in its early stages are generally asymptomatic—the strains of HPV that cause genital warts are different from those that cause cancer. That is why it is important to be screened for HPV for someone who is sexually active regularly. A test called a Pap smear, after a shortening of the name of the doctor who developed it, Georgios Papanikolaou, is used to look for signs of cancer in the cervical canal, the exit and entrance of the uterus.
Cervical cancer strikes more than 10,000 women each year. It is very rare for someone to get it except as a result of HPV infection. While a high partner count makes transmission of the virus more likely, anyone who is sexually active can acquire HPV. Not every HPV infection, even with the high-risk strains, leads to cancer. Things like smoking and smoking, stress, poor overall health, and other sexually transmitted infections such as chlamydia can make it more likely that cancer will develop.
Nonetheless, HPV prevention, quixotic a task as that is, can help reduce the incidence of cervical cancer. Many of the risk factors for HPV appear to be behaviors that are related to having more than one sexual partner—either resulting from decision, facilitating it, or simply the behaviors of someone likely to make it—and it is more likely that their contribution of these factors to getting HPV is mediated by that. Regardless, condom use provides a degree of protection, but it is imperfect because the virus can be transmitted by contact between areas of skin not covered.
The HPV vaccine is becoming more popular. It is available for children and teenagers—since HPV can be transmitted during a person’s first sexual encounter, it is recommended that people be vaccinated before they become sexually active, but the vaccine is effective through age 26 in women and 21 in men. The vaccine provides protection against the three HPV strains that cause more than three quarters of all cervical cancers, and experts say vaccination programs could cut cervical cancer deaths by as much as two-thirds.