Sex differences in HPV immunity among adults without cancer

Surveillance of human papillomavirus through salivary diagnostics - A roadmap to early detection of oropharyngeal cancer men

Human papillomavirus (HPV) is the most common sexually transmitted disease. Certain strains have the potential to cause malignancy in multiple anatomical sites if not cleared by the immune system. In most infected people, HPV is cleared within two years. However, HPV may persist in susceptible individuals with certain risk factors, eventually leading to malignancy. New evidence suggests that over 75% of all oropharyngeal cancers (OPC) are directly attributable to HPV. It is estimated that prophylactic HPV vaccination alone may take at least 25 years to have a significant impact on reducing the incidence of OPC. The temporal link between detection of oral HPV, persistence of the infection and the subsequent development of OPC have been well established. Moreover, men have threefold higher risk than women for acquiring HPV-OPC. This comprehensive review focuses on OPC development in men, highlighting the risk factors associated with malignant transformation of HPV-OPC. Current evidence is insufficient to determine whether early identification of at-risk demographics, screening, and prompt diagnosis result in improved outcomes. Hitherto, the effectiveness of an oral HPV screening program in this regard has not been investigated. Nevertheless, the potential to emulate the success of the cervical screening program remains a very real possibility.

Association of naturally acquired type-specific HPV antibodies and subsequent HPV re-detection: systematic review and meta-analysis

BACKGROUND

Understanding the role of naturally acquired (i.e., infection-induced) human papillomavirus (HPV) antibodies against reinfection is important given the high incidence of this sexually transmitted infection. However, the protective effect of naturally acquired antibodies in terms of the level of protection, duration, and differential effect by sex remains incompletely understood. We conducted a systematic review and a meta-analysis to (1) strengthen the evidence on the association between HPV antibodies acquired through past infection and subsequent type-specific HPV detection, (2) investigate the potential influence of type-specific HPV antibody levels, and (3) assess differential effects by HIV status.

METHODS

We searched Embase and Medline databases to identify studies which prospectively assessed the risk of type-specific HPV detection by baseline homologous HPV serostatus among unvaccinated individuals. Random-effect models were used to pool the measures of association of naturally acquired HPV antibodies against subsequent incident detection and persistent HPV positivity. Sources of heterogeneity for each type were assessed through subgroup analyses stratified by sex, anatomical site of infection, male sexual orientation, age group, and length of follow-up period. Evidence of a dose-response relationship of the association between levels of baseline HPV antibodies and type-specific HPV detection was assessed. Finally, we pooled estimates from publications reporting associations between HPV serostatus and type-specific HPV detection by baseline HIV status.

RESULTS

We identified 26 publications (16 independent studies, with 62,363 participants) reporting associations between baseline HPV serostatus and incident HPV detection, mainly for HPV-16 and HPV-18, the most detected HPV type. We found evidence of protective effects of baseline HPV seropositivity and subsequent detection of HPV DNA (0.70, 95% CI 0.61-0.80, NE = 11) and persistent HPV positivity (0.65, 95% CI 0.42-1.01, NE = 5) mainly for HPV-16 among females, but not among males, nor for HPV-18. Estimates from 8 studies suggested a negative dose-response relationship between HPV antibody level and subsequent detection among females. Finally, we did not observe any differential effect by baseline HIV status due to the limited number of studies available.

CONCLUSION

We did not find evidence that naturally acquired HPV antibodies protect against subsequent HPV positivity in males and provide only modest protection among females for HPV-16. One potential limitation to the interpretation of these findings is potential misclassification biases due to different causes.

Human Papillomavirus Oral Infection: Review of Methodological Aspects and Epidemiology

Oral infection by Human Papillomavirus (HPV) has recently gained great attention because of its involvement in the development of a subset of head and neck squamous cell carcinoma. The role of specific Alpha-HPVs in this regard has been well established, whereas the contribution of other genera is under investigation. Despite their traditional classification as “cutaneous” types, Beta and Gamma HPVs are frequently detected in oral samples. Due to the lack of a standardized protocol, a large variety of methodologies have been used for oral sample collection, DNA extraction, HPV detection and genotyping. Laboratory procedures influence the evaluation of oral HPV prevalence, which largely varies also according to the population characteristics, e.g., age, gender, sexual behavior, Human Immunodeficiency Virus (HIV) status. Nevertheless, oral infection by Beta and Gamma HPVs seems to be even more common than Alpha-HPVs. The latter is 5–7% in the general population, and increases up to 30% approximately in HIV-infected men who have sex with men. Despite major advances in the evaluation of oral HPV prevalence, its natural history is still little understood, especially for Beta and Gamma HPVs. The latest technologies, such as Next Generation Sequencing (NGS), can be exploited to gain new insights into oral HPV, and to improve the identification of novel HPV types.

The Key Differences between Human Papillomavirus-Positive and -Negative Head and Neck Cancers: Biological and Clinical Implications

Head and neck squamous cell carcinoma (HNSCC) is a unique malignancy associated with two distinct risk factors: exposure to typical carcinogens and infection of human papillomavirus (HPV). HPV encodes the potent oncoproteins E6 and E7, which bypass many important oncogenic processes and result in cancer development. In contrast, HPV-negative HNSCC is developed through multiple mutations in diverse oncogenic driver genes. While the risk factors associated with HPV-positive and HPV-negative HNSCCs are discrete, HNSCC patients still show highly complex molecular signatures, immune infiltrations, and treatment responses even within the same anatomical subtypes. Here, we summarize the current understanding of biological mechanisms, treatment approaches, and clinical outcomes in comparison between HPV-positive and -negative HNSCCs.

Biologic and behavioral associations of estrogen receptor alpha positivity in head and neck squamous cell carcinoma

OBJECTIVES

Tumor HPV status is an established independent prognostic marker for oropharynx cancer (OPC). Recent studies have reported that tumor estrogen receptor alpha (ERα) positivity is also associated with prognosis independent of HPV. Little is known about the biologic and behavioral predictors of ERα positivity in head and neck squamous cell cancer (HNSCC). We therefore explored this in a multicenter prospective cohort study.

MATERIALS AND METHODS

Participants with HNSCC completed a survey and provided a blood sample. Tumor samples were tested for ERα using immunohistochemistry. ERα positivity was defined as ≥1%, standardized by the American Society of Clinical Oncology/College of American Pathologists in breast cancer. Characteristics were compared with χ² and Fisher's exact test. Odds ratios (OR) were calculated using logistic regression.

RESULTS

Of 318 patients with HNSCC, one third had ERα positive tumors (36.2%, n = 115). Odds of ERα expression were significantly increased in those with HPV-positive tumors (OR = 27.5, 95% confidence interval[CI] 12.1-62), smaller tumors (≤T2, OR = 3.6, 95% CI 1.9-7.1), male sex (OR = 2.0, 95% CI 1.1-3.6), overweight/obesity (BMI ≥ 25, OR = 1.9, 95% CI 1.1-3.3), and those married/living with a partner (OR = 1.7, 95% CI 1.0-3.0). In a multivariate model, HPV-positivity (aOR = 27.5, 95% CI 11.4-66) and small tumor size (≤T2, aOR = 2.2, 95% CI 1.0-4.8) remained independently associated with ERα status. When restricted to OPC (n = 180), tumor HPV status (aOR = 17.1, 95% CI 2.1-137) and small tumor size (≤T2, aOR = 4.0 95% CI 1.4-11.3) remained independently associated with ERα expression.

CONCLUSION

Tumor HPV status and small tumor size are independently associated with ERα expression in HNSCC.

Prevalence of oral human papillomavirus infection: Impact of sex, race/ethnicity and vaccination status

BACKGROUND

Prior studies have demonstrated differences by sex and race/ethnicity in oral HPV prevalence. This study examined the impact of vaccination on these disparities.

METHODS

We examined participants 18-59 years old in the National Health and Nutrition Examination Survey from 2011-16 who reported their HPV vaccination status and submitted an adequate oral sample (N=9,437). Oral prevalence of HPV, grouped by any, low risk, high risk, 4vHPV, 9vHPV, and non-vaccine types, was examined by sex, race/ethnicity and vaccination status. Binary logistic regression was used to estimate prevalence ratios by vaccination status. Multivariable logistic regression models controlled for age, sex, and race/ethnicity.

RESULTS

The prevalence of any type, non-vaccine type, low-risk, high-risk, 4vHPV, and 9vHPV types was higher among males than females, even among vaccinated participants. Examination of racial/ethnic differences demonstrated differences in all HPV groups among unvaccinated males and among low-risk types in females. In all but the 2 vaccine-type groups, the prevalence of oral HPV was notably higher among black males compared to other groups. Significant differences were not observed by race/ethnicity among vaccinated males or females.

CONCLUSION

Males tested positive for oral HPV more frequently than females, even among those vaccinated. This may have resulted from a lower frequency of males being vaccinated before initiating oral sex than females. Vaccination of males at the recommended age, therefore, may decrease differences in oral HPV by sex. Racial/ethnic differences were observed only in unvaccinated individuals, suggesting these disparities will decrease as more individuals are vaccinated.

Timing, number, and type of sexual partners associated with risk of oropharyngeal cancer

BACKGROUND

Case-control studies from the early 2000s demonstrated that human papillomavirus-related oropharyngeal cancer (HPV-OPC) is a distinct entity associated with number of oral sex partners. Using contemporary data, we investigated novel risk factors (sexual debut behaviors, exposure intensity, and relationship dynamics) and serological markers on odds of HPV-OPC.

METHODS

HPV-OPC patients and frequency-matched controls were enrolled in a multicenter study from 2013 to 2018. Participants completed a behavioral survey. Characteristics were compared using a chi-square test for categorical variables and a t test for continuous variables. Adjusted odds ratios (aOR) were calculated using logistic regression.

RESULTS

A total of 163 HPV-OPC patients and 345 controls were included. Lifetime number of oral sex partners was associated with significantly increased odds of HPV-OPC (>10 partners: odds ratio [OR], 4.3 [95% CI, 2.8-6.7]). After adjustment for number of oral sex partners and smoking, younger age at first oral sex (<18 vs >20 years: aOR, 1.8 [95% CI, 1.1-3.2]) and oral sex intensity (>5 sex-years: aOR, 2.8 [95% CI, 1.1-7.5]) remained associated with significantly increased odds of HPV-OPC. Type of sexual partner such as older partners when a case was younger (OR, 1.7 [95% CI, 1.1-2.6]) or having a partner who had extramarital sex (OR, 1.6 [95% CI, 1.1-2.4]) was associated with HPV-OPC. Seropositivity for antibodies to HPV16 E6 (OR, 286 [95% CI, 122-670]) and any HPV16 E protein (E1, E2, E6, E7; OR, 163 [95% CI, 70-378]) was associated with increased odds of HPV-OPC.

CONCLUSION

Number of oral sex partners remains a strong risk factor for HPV-OPC; however, timing and intensity of oral sex are novel independent risk factors. These behaviors suggest additional nuances of how and why some individuals develop HPV-OPC.

Quantitative Oral HPV16 and HPV18 Detection in Persons Attending Dental Clinics

OBJECTIVE

This study aimed to assess quantitative human papillomavirus (HPV) type 16 and HPV18 detection in oral rinses obtained in dental offices in Seattle, Washington.

METHODS

We evaluated oral rinses collected during dental visits from 2016 to 2018. Multiplex TaqMan quantitative polymerase chain reaction was used to determine HPV16 and HPV18 viral load (VL).

RESULTS

Of 15,313 persons, 152 (1%) had detectable oral HPV16/18. Men were at higher risk of oral HPV16/18 infection than women (1.6% vs. 0.6%; odds ratio, 3.2; 95% confidence interval, 2.1-4.4). Compared with women, men with HPV16 were older (median, 55 vs. 48 years; P < 0.001) and had higher VL (39.7 vs. 1.1 copies/mL, P < 0.001). Of 39 with HPV16 at baseline and a second oral rinse, 13 remained positive at subsequent rinse; of 8 with HPV18 at baseline, 2 remained positive at subsequent rinse. Persons with consecutive positive test results were all men and had higher baseline VL compared with those with first positive and second negative samples.

CONCLUSION

Oral rinse is an acceptable method of HPV testing, and persons are interested in testing. Overall HPV16/18 prevalence was low, and detection was more frequent among men than women, especially at higher copy numbers. HPV16 persistence was more common in men with high VL at baseline test. Future studies are needed to evaluate the feasibility of an effective secondary prevention strategy for oropharyngeal cancer using quantitative oral HPV detection.

Humoral Response to HPV16 Proteins in Persons with Anal High-Grade Squamous Intraepithelial Lesion or Anal Cancer

BACKGROUND

This study was launched to evaluate the association of early and late antibodies to human papillomavirus 16 (HPV16) detection and risk of anal high-grade squamous intraepithelial lesions (HSIL) or cancer.

METHODS

We analyzed data from persons with anal HSIL or cancer and controls from a case-control study in Seattle, Washington. Sera were evaluated for HPV16 early (E1, E2, E4, E6, and E7) and late (L1) antibodies by multiplex serology. Logistic regression models were used to assess serologic associations with risk of anal HSIL or cancer.

RESULTS

The study included 67 participants with anal HSIL, 116 with anal cancer, and 830 population-based controls. HPV16 seropositivity to L1 [adjusted OR (aOR), 13.8; 95% confidence interval (CI), 7.4-25.8], E4 (aOR, 2.3; 95% CI, 1.1-4.5), and E6 (aOR, 4.9; 95% CI, 1.1-21.2) was associated with HSIL; and detection of all antibodies to HPV16 late and early proteins was associated with increased risk of anal cancer ranging from aOR 1.7 to 32.5 [L1 aOR, 12.5 (95% CI, 7.3-21.7); E1 aOR, 24.9 (95% CI, 10.3-59.9); E2 aOR, 6.3 (95% CI, 3.4-11.7); E4 aOR, 2.8 (95% CI, 1.6-4.8); E6 aOR, 32.5 (95% CI, 14.2-74.4); and E7 aOR, 1.7 (95% CI, 1.0-3.0)].

CONCLUSIONS

HPV serologic markers proved to be specific for identifying anal cancer. HPV16 E6 seropositivity is relatively uncommon in persons without anal cancer.

IMPACT

This large study comprehensively describes the distinct antibody responses to the HPV16 proteins in persons with anal HSIL or anal cancer. Antibodies to HPV16 E6 should be further evaluated as a potential biomarker for anal cancer prevention.

Risk factors for human papillomavirus-positive nonoropharyngeal squamous cell carcinoma

BACKGROUND

Human papillomavirus (HPV)-positive oropharyngeal cancer (HPV-OPC) is distinct from HPV-unassociated head and neck cancer. However, whether risk factors for HPV-positive oropharyngeal and nonoropharyngeal squamous cell cancer are the same is unclear.

METHODS

Incident cases of HPV-positive head and neck cell cancer and matched non-cancer controls were enrolled in a multi-institutional, prospective study examining risk factors, biomarkers, and survival.

RESULTS

HPV-nonOPC (n = 20) were more likely to be ever smokers than controls (n = 80, OR 3.49, 95%CI 1.11-10.9) and HPV-OPC (n = 185, OR 3.28, 95%CI 1.10-10.2). Compared with HPV-OPC, HPV-nonOPC were less likely to have had over 3 oral sexual partners (OR 0.29, 95%CI 0.06-0.9), more likely to have multimorbidity (OR 3.30, 95%CI 1.04-10.5), and less likely to have antibodies to HPV16 E6 (90% vs 28%, OR 0.05, 95%CI 0.02-0.2). HPV-nonOPC had worse 4-year OS (77% vs 96%, P = .001) and RFS (69% vs 94%, P < .001) than HPV-OPC.

CONCLUSIONS

HPV-positive nonoropharyngeal are distinct from HPV-positive oropharyngeal cancers.

A global epidemic increase of an HPV-induced tonsil and tongue base cancer - potential benefit from a pan-gender use of HPV vaccine

In 2007, human papillomavirus (HPV) type 16 was finally recognized as a risk factor, besides smoking and alcohol, for oropharyngeal squamous cell carcinoma (OPSCC), including tonsillar squamous cell carcinoma (TSCC), by the International Agency for Research against Cancer. Just before, in 2006, the Food and Drug Administration had approved Gardasil, the first vaccine against HPV16, 18, 6 and 11, for preventive vaccination women against cervical cancer. Concurrently, some Western countries, where smoking was decreasing, disclosed an epidemic increase in the incidence of OPSCC, especially of TSCC and base of tongue cancer (BOTSCC), together accounting for 80-90% of all OPSCCs, and mainly affecting men. The epidemic was later revealed to be due to a rise in HPV-positive cases, and scientists in the field suggested HPV vaccination also of boys. Globally, there are roughly 96 000 incident OPSCC cases/year of which 20-24% are caused by HPV, thereby accounting for around 22 000 OPSCC cases annually. Of these cases, 80-90% are due to HPV16 infection and would be prevented with the presently registered HPV vaccines. In Western countries, such as Sweden (with almost 400 TSCC and BOTSCC cases per year) and the United States, HPV prevalence in OPSCC is higher and around 70%. HPV vaccination of girls has been initiated in many countries, and the vaccines have been efficient and their side effects limited. HPV vaccination of boys has, however, been the exception, but should definitely not be delayed any further. It would benefit both girls and boys directly, and result in better and more robust herd immunity. Today, we have the possibility to eliminate several high-risk HPV types in the younger generations and avoid more than 600 000 cancer cases annually worldwide, and this possibility should be embraced by offering global pan-gender HPV vaccination.