“Disease prevention and early detection are key in the battle against cancer,” said Dr. Celestine Tung, an assistant professor in the department of obstetrics and gynecology in the division of gynecologic oncology at BCM. “With cervical cancer, now we have a way to prevent it with the HPV vaccine.”
HPV and cervical cancer
Approximately 95 percent of cervical cancers are associated with HPV infections, and between 70 to 80 percent of cervical cancers are related to HPV 16 and HPV 18 viral subtypes or strains, Tung said.
HPV is the most common sexually transmitted infection affecting between 30 to 90 percent of sexually active women. Most of the time, a woman’s body will fight off the virus on its own and resolve within 12 months, with 90 percent of women clearing the virus after two years, Tung said.
But in a small percentage of women, the virus will persist.
“It is the strains of HPV that persist that we are worried about,” said Tung. “They are associated with the development of cervical dysplasia and cervical cancer.”
Cervical dysplasia is characterized by precancerous abnormal cell growth on the cervix.
Different types of vaccines
Two HPV vaccines have been approved for by the U.S. Food and Drug Administration.
The quadrivalent HPV vaccine, Gardasil, protects specifically against four strains of HPV: HPV 16 and 18, potentially preventing up to 70 percent of cervical cancer cases, and HPV 6 and 11, which are associated with genital warts.
Cervarix is a bivalent HPV vaccine which protects against HPV 16 and 18.
How to get the vaccine
The American College of Obstetrics and Gynecology and the U.S. Advisory Committee on Immunization Practices recommend routine vaccination of all 11- to 12- year old girls with “catch up” vaccination of those 13 to 36-years-old.
The vaccination series can be started as early as 9-years old. Three shots are given over a period of six months.
The Centers for Disease Control and Prevention also recommends vaccinating all boys between 11 to 21 years of age but is approved for all young men between 9 to 26 years old.
“The goal is to inoculate prior to exposure to the virus,” said Tung.
Parents of young girls and boys should speak with their child’s pediatrician and/or gynecologist about getting the vaccine, and young women should speak to their gynecologist, if they have questions or concerns, she said.
“We do not know yet why certain HPV strains persist and what causes the transformation to cancer, but there is a lot of research in this area,” said Tung.
Additionally, there is more data demonstrating a potential therapeutic effect in women with cervical dysplasia or cancer.
Importance of pap smears
In addition to the vaccine, women should also keep up with annual well-woman exams with their gynecologist, including pap smears.
“New guidelines have been issued recently that suggest women should have their first pap smear at age 21, regardless of sexual activity,” said Tung. “Based on age and various risk factors, pap smears are performed on a 1 to 3 year basis.”
The updated guidelines were issued by the American College of Obstetrics and Gynecology in October 2011.
Tung stressed even though a woman may not need a pap smear every year, she should still have an examination annually.
It is important for a woman to discuss her risk and individual screening plan with her doctor, Tung said.
Risk, early warning signs and treatment
Women with increased sexual behaviors are at a high risk of contracting HPV and other STDs, which in turn raises the risk of cervical cancer, Tung said.
Smoking also significantly increases the risk of cervical dysplasia and cancer. “Patients always ask what can they do to prevent these conditions from worsening or coming back,” said Tung. “I always tell them that the most helpful thing is to stop smoking.”
Early warning signs of cervical cancer may include abnormal bleeding or bleeding after intercourse.
If diagnosed early, cervical cancer can be cured, Tung said.