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Robert K. L. Pickard

University Health Network

Publishes on Head and Neck Cancer Studies, Cervical Cancer and HPV Research, Oral health in cancer treatment. 29 papers and 3.1k citations.

29Publications
3.1kTotal Citations

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Prevalence of Oral HPV Infection in the United States, 2009-2010
Cited by 1.1kOpen Access

CONTEXT: Human papillomavirus (HPV) infection is the principal cause of a distinct form of oropharyngeal squamous cell carcinoma that is increasing in incidence among men in the United States. However, little is known about the epidemiology of oral HPV infection. OBJECTIVE: To determine the prevalence of oral HPV infection in the United States. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study was conducted as part of the National Health and Nutrition Examination Survey (NHANES) 2009-2010, a statistically representative sample of the civilian noninstitutionalized US population. Men and women aged 14 to 69 years examined at mobile examination centers were eligible. Participants (N = 5579) provided a 30-second oral rinse and gargle with mouthwash. For detection of HPV types, DNA purified from oral exfoliated cells was evaluated by polymerase chain reaction and type-specific hybridization. Demographic and behavioral data were obtained by standardized interview. Statistical analyses used NHANES sample weights to provide weighted prevalence estimates for the US population. MAIN OUTCOME MEASURES: Prevalence of oral HPV infection. RESULTS: The prevalence of oral HPV infection among men and women aged 14 to 69 years was 6.9% (95% CI, 5.7%-8.3%) and of HPV type 16 was 1.0% (95% CI, 0.7%-1.3%). Oral HPV infection followed a bimodal pattern with respect to age, with peak prevalence among individuals aged 30 to 34 years (7.3%; 95% CI, 4.6%-11.4%) and 60 to 64 years (11.4%; 95% CI, 8.5%-15.1%). Men had a significantly higher prevalence than women for any oral HPV infection (10.1% [95% CI, 8.3%-12.3%] vs 3.6% [95% CI, 2.6%-5.0%], P < .001; unadjusted prevalence ratio [PR], 2.80 [95% CI, 2.02-3.88]). Infection was less common among those without vs those with a history of any type of sexual contact (0.9% [95% CI, 0.4%-1.8%] vs 7.5% [95% CI, 6.1%-9.1%], P < .001; PR, 8.69 [95% CI, 3.91-19.31]) and increased with number of sexual partners (P < .001 for trend) and cigarettes smoked per day (P < .001 for trend). Associations with age, sex, number of sexual partners, and current number of cigarettes smoked per day were independently associated with oral HPV infection in multivariable models. CONCLUSION: Among men and women aged 14 to 69 years in the United States, the overall prevalence of oral HPV infection was 6.9%, and the prevalence was higher among men than among women.

Validation of Methods for Oropharyngeal Cancer HPV Status Determination in US Cooperative Group Trials
Richard C. Jordan, Mark W. Lingen, Bayardo Perez‐Ordoñez et al.|The American Journal of Surgical Pathology|2012
Cited by 377Open Access

Tumor human papillomavirus (HPV) status is a prognostic factor for oropharyngeal cancer, but classification methods are not standardized. Here we validate the HPV classification methods used in US cooperative group trials. Tumor DNA and RNA purified from 240 paraffin-embedded oropharyngeal cancers diagnosed from 2000 to 2009 were scored as evaluable if positive for DNA and mRNA controls by quantitative polymerase chain reaction (PCR). Eighteen high-risk (HR) HPV types were detected in tumors by consensus PCR, followed by HR-HPV E6/7 oncogene expression analysis by quantitative reverse transcriptase PCR. The sensitivity (S), specificity (SP), and positive (PPV) and negative predictive values (NPV) of p16 expression detected by immunohistochemistry (IHC) and HPV16 detected by in situ hybridization (ISH) were evaluated in comparison with HR-HPV E6/7 oncogene expression. Interrater agreement among 3 pathologists was evaluated by κ statistics. Of 235 evaluable tumors, 158 (67%; 95% confidence interval, 61.2-73.3) were positive for HR-HPV E6/7 oncogene expression [HPV type 16 (92%), 18 (3%), 33 (3%), 35 (1%), or 58 (1%)]. p16 IHC had high sensitivity (S 96.8%, SP 83.8%, PPV 92.7%, and NPV 92.5%), whereas HPV16 ISH had high specificity (S 88.0%, SP 94.7%, PPV 97.2%, and NPV 78.9%) for HR-HPV oncogene expression. Interrater agreement was excellent for p16 (κ=0.95 to 0.98) and HPV16 ISH (κ=0.83 to 0.91). Receiver operating curve analysis determined the cross-product of p16 intensity score and percentage of tumor staining to optimally discriminate HR-HPV E6/7-positive and HR-HPV E6/7-negative tumors. p16 IHC and HPV16 ISH assays show excellent performance, with high sensitivity and specificity, respectively. A new validated H-score for p16 IHC assessment is proposed. Appropriate assay choice depends on clinical implications of a false-positive or false-negative test.

Low etiologic fraction for high-risk human papillomavirus in oral cavity squamous cell carcinomas
Cited by 348Open Access

BACKGROUND: Human papillomavirus (HPV) is a cause of oropharyngeal cancer, but a role for HPV in the etiology of oral cavity squamous cell carcinomas (OCSCC) remains uncertain. METHODS: We sought to estimate the etiologic fraction for HPV among consecutive, incident OCSCC diagnosed from 2005 to 2011 at four North American hospitals. DNA and RNA purified from paraffin-embedded tumors were considered evaluable if positive for DNA and mRNA control genes by quantitative PCR. Fifteen high-risk (HR) HPV types were detected in tumors by consensus PCR followed by type-specific HR-HPV E6/7 oncogene expression by quantitative reverse-transcriptase PCR. P16 expression was evaluated by immunohistochemistry (IHC). A study of 400 cases allowed for precision to estimate an etiologic fraction of as low as 0% (97.5% confidence interval, 0-0.92%). RESULTS: Of 409 evaluable OCSCC, 24 (5.9%, 95%CI 3.6-8.2) were HR-HPV E6/7 expression positive; 3.7% (95%CI 1.8-5.5) for HPV16 and 2.2% (95%CI 0.8-3.6) for other HR-HPV types. HPV-positive tumors arose from throughout the oral cavity (floor of mouth [n=9], anterior tongue [6], alveolar process [4], hard palate [3], gingiva [1] and lip [1]) and were significantly associated with male gender, small tumor stage, poor tumor differentiation, and basaloid histopathology. P16 IHC had very good-to-excellent sensitivity (79.2%, 95%CI 57.9-92.9), specificity (93.0%, 95%CI 90.0-95.3), and negative-predictive value (98.6%, 95%CI 96.8-99.6), but poor positive-predictive value (41.3%, 95%CI 27.0-56.8) for HR-HPV E6/7 expression in OCSCC. CONCLUSION: The etiologic fraction for HR-HPV in OCSCC was 5.9%. p16 IHC had poor positive predictive value for detection of HPV in these cancers.

Effect of Prophylactic Human Papillomavirus (HPV) Vaccination on Oral HPV Infections Among Young Adults in the United States
Anil K. Chaturvedi, Barry I. Graubard, Tatevik Broutian et al.|Journal of Clinical Oncology|2017
Cited by 314

Purpose The incidence of human papilloma virus (HPV)–positive oropharyngeal cancers has risen rapidly in recent decades among men in the United States. We investigated the US population–level effect of prophylactic HPV vaccination on the burden of oral HPV infection, the principal cause of HPV-positive oropharyngeal cancers. Methods We conducted a cross-sectional study of men and women 18 to 33 years of age (N = 2,627) within the National Health and Nutrition Examination Survey 2011 to 2014, a representative sample of the US population. Oral HPV infection with vaccine types 16, 18, 6, or 11 was compared by HPV vaccination status, as measured by self-reported receipt of at least one dose of the HPV vaccine. Analyses accounted for the complex sampling design and were adjusted for age, sex, and race. Statistical significance was assessed using a quasi-score test. Results Between 2011 and 2014, 18.3% of the US population 18 to 33 years of age reported receipt of at least one dose of the HPV vaccine before the age of 26 years (29.2% in women and 6.9% in men; P &lt; .001). The prevalence of oral HPV16/18/6/11 infections was significantly reduced in vaccinated versus unvaccinated individuals (0.11% v 1.61%; P adj = .008), corresponding to an estimated 88.2% (95% CI, 5.7% to 98.5%) reduction in prevalence after model adjustment for age, sex, and race. Notably, the prevalence of oral HPV16/18/6/11 infections was significantly reduced in vaccinated versus unvaccinated men (0.0% v 2.13%; P adj = .007). Accounting for vaccine uptake, the population-level effect of HPV vaccination on the burden of oral HPV16/18/6/11 infections was 17.0% overall, 25.0% in women, and 6.9% in men. Conclusion HPV vaccination was associated with reduction in vaccine-type oral HPV prevalence among young US adults. However, because of low vaccine uptake, the population-level effect was modest overall and particularly low in men.

Human papillomavirus and the landscape of secondary genetic alterations in oral cancers
Maura L. Gillison, Keiko Akagi, Weihong Xiao et al.|Genome Research|2018
Cited by 235Open Access

Human papillomavirus (HPV) is a necessary but insufficient cause of a subset of oral squamous cell carcinomas (OSCCs) that is increasing markedly in frequency. To identify contributory, secondary genetic alterations in these cancers, we used comprehensive genomics methods to compare 149 HPV-positive and 335 HPV-negative OSCC tumor/normal pairs. Different behavioral risk factors underlying the two OSCC types were reflected in distinctive genomic mutational signatures. In HPV-positive OSCCs, the signatures of APOBEC cytosine deaminase editing, associated with anti-viral immunity, were strongly linked to overall mutational burden. In contrast, in HPV-negative OSCCs, T&gt;C substitutions in the sequence context 5′-ATN-3′ correlated with tobacco exposure. Universal expression of HPV E6*1 and E7 oncogenes was a sine qua non of HPV-positive OSCCs. Significant enrichment of somatic mutations was confirmed or newly identified in PIK3CA , KMT2D , FGFR3 , FBXW7 , DDX3X , PTEN , TRAF3 , RB1 , CYLD , RIPK4 , ZNF750 , EP300 , CASZ1 , TAF5 , RBL1 , IFNGR1 , and NFKBIA . Of these, many affect host pathways already targeted by HPV oncoproteins, including the p53 and pRB pathways, or disrupt host defenses against viral infections, including interferon (IFN) and nuclear factor kappa B signaling. Frequent copy number changes were associated with concordant changes in gene expression. Chr 11q (including CCND1 ) and 14q (including DICER1 and AKT1 ) were recurrently lost in HPV-positive OSCCs, in contrast to their gains in HPV-negative OSCCs. High-ranking variant allele fractions implicated ZNF750 , PIK3CA , and EP300 mutations as candidate driver events in HPV-positive cancers. We conclude that virus-host interactions cooperatively shape the unique genetic features of these cancers, distinguishing them from their HPV-negative counterparts.