With thousands of new cases diagnosed each year in the United States, cervical cancer is prominent but, more importantly, preventable. Lauren Tom, NP, Gynecologic Oncology Care Team, Parkview Cancer Institute, shares more on the risk factors, the importance of routine screenings and how the HPV vaccine can save lives.
How prevalent is cervical cancer?
Cervical cancer is the 20th most common cancer worldwide. As of 2017, there were 291,704 women with cervical cancer in America. And, according to the National Cancer Institute (NCI), there was an estimated 13,800 new cervical cancer cases in the United States in 2020. There were 4,290 women in 2020 who died from cervical cancer. The median age of diagnosis is 50, but most cervical cancer is diagnosed between 35 and 44. The current five-year survival rate for cervical cancer is 66.1%.
What is the connection between the human papillomavirus (HPV) and cervical cancers?
HPV is a virus that has over 200 strains. It’s passed from person to person through oral, vaginal, and anal intercourse as well as sexual touching and skin-to-skin contact. The vast majority of people have been infected with HPV at some point in their lives. In most cases, the immune system clears the virus and there are no lasting infections or side effects. If the infection is not cleared, low risk HPV strains may cause genital warts, while high risk HPV infections may persist, causing chronic changes to cells that can lead to cancer.
HPV 16 and HPV 18 are the two most dangerous strains and the two that most often lead to cervical cancer. Although HPV causes virtually all cervical cancers, it is also responsible for 90% of anal cancers, 75% of vaginal cancers, 70% of vulvar cancers, 70% of oropharyngeal cancers and 60% of penile cancers.
What are the risk factors for cervical cancer?
The largest risk factor for cervical cancer is HPV infection. Other risk factors include smoking, having multiple sexual partners, early age of initial intercourse and HIV infection.
How often should women get tested for HPV or receive a cervical cancer screening?
- Women 25 and younger should not receive HPV testing alone, as they are more likely to have and be able to clear HPV infections.
- Starting at age 21, all women should receive an annual pelvic exam by a provider as well as a bimanual exam to feel for any masses, tenderness or abnormalities in the pelvis. Women in this age group should have a pap smear every three years until age 29.
- After 29, if testing has been normal, the patient may transition to a cadence of HPV testing every three years or a pap smear and HPV testing together every five years.
- For women 30-65 who have never had an HPV infection, HPV testing alone may be completed every three years or completed in conjunction with pap testing every five years.
If HPV 16 or 18 are present in a sample, the patient must have a colposcopy, which is a procedure completed in office where a provider looks at the cervix and vagina using a microscope and takes biopsies of any tissue that appears abnormal. The purpose of this is to identify and remove pre-cancerous lesions before they can develop into cancer. Once HPV 16 or 18 are identified, screening will become more frequent.
If HPV High Risk (the 12 other strains of HPV most likely to cause cervical, vaginal or vulvar cancers) are present on a sample, the next step is to analyze the cytology (cells). If the cytology is abnormal, the patient is also required to complete colposcopy. These women are also screened with HPV testing on an annual basis.
What is the difference between a pap test and an HPV test?
Both a pap test and HPV test are completed by brushing the cervix to gather cells during an exam. With pap testing, the cells are put onto a slide and analyzed for abnormalities ranging from atrophy to precancer or cancer. HPV testing uses the same sample, but instead this sample is tested for the HPV virus on the cervix, specifically HPV 16, 18 and the 12 other strains that cause cervical, vaginal and vulvar cancer.
What are the symptoms of cervical cancer?
Symptoms may include abnormal vaginal bleeding, bleeding after intercourse, foul vaginal discharge, pelvic pain and pain with intercourse. If symptoms are present, the patient should not hesitate to schedule a pelvic exam with their gynecologist.
Because of the COVID-19 pandemic, some women are delaying their routine health screenings. How does this impact cervical cancer risk?
Risk of COVID exposure does not trump the risk of putting off cervical cancer screenings. Women should not miss their cervical cancer screenings or prolong screening intervals as doing so may be deadly. Appropriate screening can identify cervical precancers before they progress to invasive cancer, and can catch aggressive disease early. In fact, 91.8% of women with local disease only at diagnosis (early stage) were alive five years after their diagnosis compared to 16.8% of women diagnosed with late-stage disease. Women should not assume that they are at low risk for cervical cancer and can skip screening, even if they have no history of HPV or abnormal pap tests. HPV infection may occur even if there have been no new sexual partners, as HPV can be dormant for years.
What are the best ways to prevent cervical cancer?
The most effective method of preventing cervical cancer is through primary intervention through vaccination. Gardasil®9 vaccination is approved for women ages 9-45, with preference for receiving the vaccine between the ages of 9-26. Women who receive their vaccination prior to age 15 need two doses of the vaccine, while women older than 15 require three doses. Gardasil 9 protects women from seven high risk HPV strains, including HPV 16 and 18, and two low risk strains. Even women who have previously had an HPV infection benefit from vaccination as they will gain protection from additional strains they have not had exposure to.
Gardasil vaccination is also recommended for boys starting at age 9. The NCI states that both boys and girls benefit most from the vaccine if received prior to HPV infection; the goal is to vaccinate prior to the initiation of any sexual contact. Although men are often asymptomatic with HPV infection, and penile cancers are far less common than cervical cancer, vaccinating men is key to eradicating cervical cancer in women.
Smoking often coincides with cervical cancer because smoking impairs the ability of cells to carry oxygen to tissues and to repair damaged cells. Women who smoke are 30% less likely to clear an HPV infection compared to women who do not smoke. Smoking cessation is key to decreasing the risk of cervical cancer.
Limiting sexual partners and prolonging the age of initial intercourse/sexual touching is another way to decrease cervical cancer risk. As previously mentioned, and according to the NCI, if children are vaccinated against HPV prior to starting these activities, the protection against HPV is in place, and the virus is unable to spread. With every additional sexual partner, or even only one partner that has had multiple partners, the risk of a high risk HPV strain being transmitted increases.