From the Guidelines
The most significant risk factor for cervical cancer from HPV is persistent infection with high-risk HPV types, particularly HPV 16 and 18, which are detected in 99% of cervical tumors. According to the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up of cervical cancer 1, HPV 16 and 18 are the most oncogenic subtypes, causing the majority of cervical cancers.
Key Points
- The large geographic variation in cervical cancer rates reflects differences in the availability of screening and in human papillomavirus (HPV) infection prevalence 1.
- HPV vaccination before exposure to the virus is highly effective at preventing infection with the most carcinogenic HPV types, including HPV 16 and 18, and can prevent > 70% of cervical cancers 1.
- Regular cervical cancer screening through Pap tests and/or HPV testing is crucial for early detection of precancerous changes, as cervical cancer typically develops slowly over 10-20 years from initial HPV infection.
- Several factors increase the risk of persistent HPV infection, including smoking, immunosuppression, long-term oral contraceptive use, having multiple sexual partners, and early age at first sexual intercourse.
Prevention and Screening
The introduction of HPV vaccination programs has been shown to have a beneficial effect at the population level, including decreases in the incidence of high-grade cervical abnormalities, the prevalence of vaccine HPV types, and the incidence of genital warts 1. Additionally, HPV-based cervical screening provides 60%–70% greater protection against invasive cervical cancer compared to conventional cytology 1.
Recommendations
Women with persistent high-risk HPV infections should follow their healthcare provider's recommendations for more frequent screening and follow-up, and HPV vaccination should be administered before exposure to the virus to prevent infection with the most carcinogenic HPV types 1.
From the FDA Drug Label
The results of these trials are shown in Table 6 below Table 6: Analysis of Efficacy of GARDASIL in the PPE* Population for Vaccine HPV Types Disease Endpoints GARDASIL AAHS Control % Efficacy (95% CI) N Number of cases N Number of cases N=Number of individuals with at least one follow-up visit after Month 7 CI=Confidence Interval Note 1: Point estimates and confidence intervals are adjusted for person-time of follow-up Note 2: Table 6 does not include cases due to HPV types not covered by the vaccine AAHS = Amorphous Aluminum Hydroxyphosphate Sulfate, CIN = Cervical Intraepithelial Neoplasia, VIN = Vulvar Intraepithelial Neoplasia, VaIN=Vaginal Intraepithelial Neoplasia, PIN=Penile Intraepithelial Neoplasia, AIN=Anal Intraepithelial Neoplasia, AIS=Adenocarcinoma In Situ
- The PPE population consisted of individuals who received all three vaccinations within one year of enrollment, did not have major deviations from the study protocol, were naïve (PCR negative and seronegative) to the relevant HPV type(s) (Types 6,11,16, and 18) prior to dose 1 and who remained PCR negative to the relevant HPV type(s) through one month post-dose 3 (Month 7). † Analyses of the combined trials were prospectively planned and included the use of similar study entry criteria. 16- through 26-Year-Old Girls and Women† HPV 16- or 18-related CIN 2/3 or AIS 8 49 32 64 112 98.2 (93.5,99.8)
The most significant risk factor for cervical cancer from HPV is HPV 16 and 18, as they are associated with the majority of cases.
- HPV 16 and 18 are the most common high-risk types of HPV that can lead to cervical cancer.
- The vaccine has been shown to be highly effective in preventing HPV 16 and 18 related CIN 2/3 or AIS with an efficacy of 98.2% (95% CI: 93.5,99.8) 2. The data suggests that HPV 16 and 18 are the primary risk factors for cervical cancer, and vaccination against these types can significantly reduce the risk of developing cervical cancer.
From the Research
Risk Factors for Cervical Cancer from HPV
The most significant risk factor for cervical cancer from HPV is persistent infection with high-risk human papillomavirus (HPV-HR) types, particularly types 16 and 18, which are responsible for approximately 70% of cervical cancer cases 3.
Key Risk Factors
- Persistent infection with high-risk HPV types, such as HPV 16 and 18 4, 5, 6, 3
- Early age at initial sexual activity (≤ 19 years) 7
- Multiple sexual partners (> 1) 7
- Low education level (≤ high school) 7
- Non-condom contraception 7
- Abnormal cytology results (ASCUS and above) 7
- High-grade squamous intraepithelial lesion (HSIL) and above 7
Prevention and Screening
Prevention strategies include vaccination against HPV types 16 and 18, as well as regular cervical cancer screening with Pap smears and HPV testing 4, 5, 6. Early detection and treatment of precancerous lesions can help prevent the development of cervical cancer.