Cervical cancer is the fourth most common cancer affecting women globally, disproportionately impacting those in developing countries. Despite this, cervical cancer has a relatively good prognosis; over 80% of those diagnosed are expected to survive for more than one year after diagnosis, and around 60% are expected to survive for five years or more. The cause of cervical cancer has been thoroughly studied and can be attributed mainly to human papillomavirus, or HPV.
What is HPV?
HPV is a sexually transmitted infection primarily transmitted through sexual contact, including vaginal, anal, and oral sex. Therefore, it commonly infects the vaginal, anus, and mouth. It is a double-stranded DNA virus that targets the skin’s outer layer and other similar tissues. There are over 100 different types of HPV, 14 of which have been identified to cause cancer. Most people do not show any symptoms when they first get infected with HPV, and their immune systems are usually able to resolve it within one to two years. In fact, 90% of HPV infections go away without any involvement of a health care provider. In addition to cervical cancer, HPV infection can lead to other health problems such as genital warts and different types of cancers including vaginal, penis, anus, and cancers of the head and neck.
It is estimated that in their lifetime, 80% of sexually active adults will be infected with HPV. Some types of HPV can cause cervical cancer if left untreated. Figure 1 shows how an HPV infection can cause changes to the cervical cells. Over time, these changes can progress from mild (also called low-grade intraepithelial lesion [LSIL]) to severe (high-grade-intraepithelial lesion [HSIL]) and eventually become cancerous.
Figure 1. Cervical Changes
Cervical Cancer Prevention: HPV Vaccine and the Pap
Currently available vaccines prevent 70-90% HPV infections. Therefore, although effective, cannot protect against all kinds of cervical cancer and does not protect against any other types of sexually transmitted infections or diseases. Two types of HPV; HPV16 and HPV18, are most common and responsible for around 70% of cervical cancer cases. Table 1 shows the approved vaccines against HPV and the types that they protect against. According to the CDC, only Gardasil 9 is distributed in the United States currently.
Table 1. HPV Vaccines
The HPV vaccine, like any other vaccine, is a type of preventative medicine that prepares your body’s immune system to fight off infection before the exposure even happens. The HPV vaccine will expose your body to a harmless version of the virus. This allows your immune system to recognize the virus if it were to enter your body in the future. Your body creates proteins called antibodies that are ready to fight against any future exposure!
The vaccine has been shown to have long-lasting protection against HPV infections and does not weaken over time. Therefore, the best time to vaccinate against HPV is around age 9-11, generally before an individual starts to become sexually active. Studies have shown that since the HPV vaccine became available, the number of young women diagnosed with cervical cancer decreased by ~11% every year, from 2005 to 2017. Another study found that the vaccine was able to reduce cervical cancer rates by nearly 90% in women from 20 to 30 years of age compared to those who did not receive the vaccine.
Another important preventative step is screening for cervical cancer, commonly known as the Pap Test or Pap Smear. Healthcare providers usually invite women who are sexually active to get a Pap Test done around age 21, and every three years after that. The Pap Test procedure involves a small brush inserted into the vagina to collect cells from the surface of the cervix. Pap smears allow doctors to assess the state of the cervical cells, as shown in Figure 1.
Conclusions
Cervical cancer, mainly caused by HPV, is a significant health issue for women worldwide. While treatments are available, the best way to deal with cervical cancer, like any cancer, is to prevent it from happening in the first place. Early HPV vaccination is a crucial step in preventing cervical cancer and other HPV-related health problems. By choosing to get vaccinated (or vaccinating your children) and undergoing regular Pap testing, you’re taking important steps to protect your health, your child’s health, and the health of those around you!
References
For more information, check out these sources:
HPV Vaccine Information for Young Women
Large Study Confirms that HPV Vaccine Prevents Cervical Cancer
Human Papillomavirus (HPV) Vaccines
Cervical cancer
Assessing Impact of HPV Vaccination on Cervical Cancer Incidence in Women 15–29 years in the United States, 1999–2017: An Ecologic Study
“The power of science”: HPV vaccine proven to dramatically reduce cervical cancer
Survival for cervical cancer
HPV and Pap Test Results: Next Steps after an Abnormal Cervical Cancer Screening Test
https://www.cancer.gov/types/cervical/screening/abnormal-hpv-pap-test-results Assessed and Endorsed by the MedReport Medical Review Board