Weihong Xiao

PURPOSE: Recent increases in incidence and survival of oropharyngeal cancers in the United States have been attributed to human papillomavirus (HPV) infection, but empirical evidence is lacking. PATIENTS AND METHODS: HPV status was determined for all 271 oropharyngeal cancers (1984-2004) collected by the three population-based cancer registries in the Surveillance, Epidemiology, and End Results (SEER) Residual Tissue Repositories Program by using polymerase chain reaction and genotyping (Inno-LiPA), HPV16 viral load, and HPV16 mRNA expression. Trends in HPV prevalence across four calendar periods were estimated by using logistic regression. Observed HPV prevalence was reweighted to all oropharyngeal cancers within the cancer registries to account for nonrandom selection and to calculate incidence trends. Survival of HPV-positive and HPV-negative patients was compared by using Kaplan-Meier and multivariable Cox regression analyses. RESULTS: HPV prevalence in oropharyngeal cancers significantly increased over calendar time regardless of HPV detection assay (P trend < .05). For example, HPV prevalence by Inno-LiPA increased from 16.3% during 1984 to 1989 to 71.7% during 2000 to 2004. Median survival was significantly longer for HPV-positive than for HPV-negative patients (131 v 20 months; log-rank P < .001; adjusted hazard ratio, 0.31; 95% CI, 0.21 to 0.46). Survival significantly increased across calendar periods for HPV-positive (P = .003) but not for HPV-negative patients (P = .18). Population-level incidence of HPV-positive oropharyngeal cancers increased by 225% (95% CI, 208% to 242%) from 1988 to 2004 (from 0.8 per 100,000 to 2.6 per 100,000), and incidence for HPV-negative cancers declined by 50% (95% CI, 47% to 53%; from 2.0 per 100,000 to 1.0 per 100,000). If recent incidence trends continue, the annual number of HPV-positive oropharyngeal cancers is expected to surpass the annual number of cervical cancers by the year 2020. CONCLUSION: Increases in the population-level incidence and survival of oropharyngeal cancers in the United States since 1984 are caused by HPV infection.

BACKGROUND: High-risk types of human papillomavirus (HPV), including HPV-16, cause a subgroup of head and neck squamous cell carcinomas (HNSCCs). We examined whether the risk factors for HPV-16-positive HNSCCs are similar to those for HPV-16-negative HNSCCs in a hospital-based case-control study. METHODS: Case subjects (n = 240) diagnosed with HNSCC at the Johns Hopkins Hospital from 2000 through 2006 were stratified by tumor HPV-16 status as determined by in situ hybridization. Two control subjects (n = 322) without cancer were individually matched by age and sex to each HPV-16-positive and HPV-16-negative case subject. Data on risk behaviors were obtained by use of audio computer-assisted self-interview technology. Multivariable conditional logistic regression models were used to estimate the odds ratios (ORs) for HPV-16-positive HNSCC and HPV-16-negative HNSCC associated with risk factors. All statistical tests were two-sided. RESULTS: HPV-16 was detected in 92 of 240 case subjects. HPV-16-positive HNSCC was independently associated with several measures of sexual behavior and exposure to marijuana but not with cumulative measures of tobacco smoking, alcohol drinking, or poor oral hygiene. Associations increased in strength with increasing number of oral sex partners (P(trend) = .01) and with increasing intensity (joints per month, P(trend) = .007), duration (in years, P(trend) = .01), and cumulative joint-years (P(trend) = .003) of marijuana use. By contrast, HPV-16-negative HNSCC was associated with measures of tobacco smoking, alcohol drinking, and poor oral hygiene but not with any measure of sexual behavior or marijuana use. Associations increased in strength with increasing intensity (cigarettes per day), duration, and cumulative pack-years of tobacco smoking (for all, P(trend) < .001), increasing years of heavy alcohol drinking (> or = 15 years of 14 drinks per week; P(trend) = .03), and increasing number of lost teeth (P(trend) = .001). Compared with subjects who neither smoked tobacco nor drank alcohol, those with heavy use of tobacco (> or = 20 pack-years) and alcohol had an increased risk of HPV-16-negative HNSCC (OR = 4.8, 95% confidence interval [CI] = 1.8 to 12) but not of HPV-16-positive HNSCC (OR = 0.67, 95% CI = 0.29 to 1.9). CONCLUSIONS: HPV-16-positive HNSCCs and HPV-16-negative HNSCCs have different risk factor profiles, indicating that they should be considered to be distinct cancers.

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.

PURPOSE: Tobacco smoking is associated with oropharynx cancer survival, but to what extent cancer progression or death increases with increasing tobacco exposure is unknown. PATIENTS AND METHODS: Patients with oropharynx cancer enrolled onto a phase III trial of radiotherapy from 1991 to 1997 (Radiation Therapy Oncology Group [RTOG] 9003) or of chemoradiotherapy from 2002 to 2005 (RTOG 0129) were evaluated for tumor human papillomavirus status by a surrogate, p16 immunohistochemistry, and for tobacco exposure by a standardized questionnaire. Associations between tobacco exposure and overall survival (OS) and progression-free survival (PFS) were estimated by Cox proportional hazards models. RESULTS: Prevalence of p16-positive cancer was 39.5% among patients in RTOG 9003 and 68.0% in RTOG 0129. Median pack-years of tobacco smoking were lower among p16-positive than p16-negative patients in both trials (RTOG 9003: 29 v 45.9 pack-years; P = .02; RTOG 0129: 10 v 40 pack-years; P < .001). After adjustment for p16 and other factors, risk of progression (PFS) or death (OS) increased by 1% per pack-year (for both, hazard ratio [HR], 1.01; 95% CI, 1.00 to 1.01; P = .002) or 2% per year of smoking (for both, HR, 1.02; 95% CI, 1.01 to 1.03; P < .001) in both trials. In RTOG 9003, risk of death doubled (HR, 2.19; 95% CI, 1.46 to 3.28) among those who smoked during radiotherapy after accounting for pack-years and other factors, and risk of second primary tumors increased by 1.5% per pack-year (HR, 1.015; 95% CI, 1.005 to 1.026). CONCLUSION: Risk of oropharyngeal cancer progression and death increases directly as a function of tobacco exposure at diagnosis and during therapy and is independent of tumor p16 status and treatment.

Genomic instability is a hallmark of human cancers, including the 5% caused by human papillomavirus (HPV). Here we report a striking association between HPV integration and adjacent host genomic structural variation in human cancer cell lines and primary tumors. Whole-genome sequencing revealed HPV integrants flanking and bridging extensive host genomic amplifications and rearrangements, including deletions, inversions, and chromosomal translocations. We present a model of "looping" by which HPV integrant-mediated DNA replication and recombination may result in viral-host DNA concatemers, frequently disrupting genes involved in oncogenesis and amplifying HPV oncogenes E6 and E7. Our high-resolution results shed new light on a catastrophic process, distinct from chromothripsis and other mutational processes, by which HPV directly promotes genomic instability.