Improving Your Odds for Cervical Health
January is Cervical Health Awareness month, a time to spread the word about steps women can take to prevent and detect cervical cancer.
The good news? Cervical cancer is largely preventable and, if detected early, curable. The key to prevention is vaccination and the key to early detection comes down to two tests. The Food and Drug Administration (FDA) is responsible for evaluating the safety and effectiveness of these measures and determining whether to approve them before they can be used in the U.S.
Cervical cancer is cancer that forms in the cervix, the lower, narrow part of the uterus that connects with the vagina. It is caused by the human papillomavirus (HPV). In the U.S. in 2013, there were approximately 12,000 new cases of cervical cancer and 4,000 deaths, according to estimates by the National Cancer Institute.
Pap and HPV Testing
The two tests for cervical cancer are the Pap test (or Pap smear) and the HPV test. According to Shyam Kalavar, a cytologist (an expert in the microscopic examination of cells) at FDA, the Pap smear looks at cells obtained from the cervix for abnormalities that may become cervical cancer if not treated appropriately.
When a Pap smear shows abnormalities, further testing or follow-up is needed. Follow-up testing may include an HPV test to check for the presence of the types of HPV most likely to cause cancer and/or a biopsy of the cervix. There are more than 100 different kinds of HPV, and not all of them cause health problems.
"If cervical cancer is found early, it's easier to treat," Kalavar says. Because this form of cancer often causes no pain, a woman can have cervical cancer and not know it, making the importance of testing that much greater.
The Pap smear is not 100% accurate, and cervical cancer may be missed in a small number of cases. However, it usually takes years, if not decades, for abnormal cells to develop into cervical cancer. Regular Pap smears—as recommended in the 2012 guidelines from the American Cancer Society, the American Society for Coloposcopy and Cervical Pathology (ASCCP), and the American Society for Clinical Pathology—should identify changes in time for treatment.
In the original Pap smear method (known as the conventional method) cells scraped from the opening of the cervix are placed onto a glass slide and examined under a microscope, explains Kalavar. In the past 15 to 20 years, however, automated, liquid-based Pap testing, in which the sample is placed in a liquid before the cells are deposited on a glass slide and examined under a microscope, has largely replaced the original test. Currently, there are two FDA-approved liquid-based tests on the market.
Regardless of what type of Pap test is used, a woman can also be tested for the presence of high-risk types of HPV, a process known as "Pap and HPV co-testing." Co-testing is less likely to miss an abnormality than Pap testing alone. Women may want to talk to their healthcare professionals about this option.
Prevention Through Vaccination
FDA has approved two vaccines to prevent cervical cancer, Gardasil and Cervarix. According to Marion Gruber, Ph.D., director of FDA's Office of Vaccines Research and Review, "both of these vaccines are preventive and work like other vaccines that prevent diseases caused by viruses and bacteria, in that the vaccine triggers the body to produce antibodies (disease-fighting substances) to protect against infection."
FDA has determined both vaccines are effective in preventing cervical cancer caused by the two types of high-risk HPVs that cause about 70 percent of cervical cancers.
However, both vaccines are effective only if given before infection with the HPV types contained in the vaccine. Neither vaccine will protect against the types of HPV that are not included in the vaccine, which can also cause some cancers, nor can the vaccines be used to treat HPV infections or cervical cancer, Gruber says.
FDA has approved Gardasil for use in females ages 9 through 26 for the prevention of cervical cancer as well as vulvar, vaginal and anal cancers and also genital warts. It is also approved for the prevention of genital warts and anal cancer in males ages 9 through 26, and Cervarix is approved for use in females ages 9 to 25 for the prevention of cervical cancer.
"Women, including those who have been vaccinated, should continue to get Pap tests as they are essential to detect cervical cancer and precancerous changes," Gruber notes.