Abstract
Human papillomavirus (HPV) is responsible for the rising incidence of oropharyngeal squamous cell cancers (OSCC) in the United States, and yet, no screening strategies have been evaluated. Secondary prevention by means of HPV detection and cervical cytology has led to a decline in cervical cancer incidence in the United States. Here, we explored an analogous strategy by evaluating associations between HPV16 infection, cytopathology, and histopathology in two populations at elevated risk for OSCCs. In the first, a cross-sectional study population (PAP1), cytology specimens were collected by means of brush biopsy from patients presenting with oropharyngeal abnormalities. In the second (PAP2), a nested case–control study, bilateral tonsillar cytology samples were collected at 12-month intervals from HIV-infected individuals. The presence of cytopathologic abnormality in HPV16-positive tonsil brush biopsies (cases) was compared with HPV16-negative samples (controls) matched on age and gender. HPV16 was detected in samples by consensus primer PCR and/or type-specific PCR. Univariate logistic regression was used to evaluate associations. In PAP1, HPV16 alone (OR: 6.1, 95% CI: 1.6–22.7) or in combination with abnormal cytology (OR: 20, 95% CI: 4.2–95.4) was associated with OSCC. In PAP2, 4.7% (72 of 1,524) of tonsillar cytology specimens from HIV-infected individuals without oropharyngeal abnormalities were HPV16 positive. Tonsillar HPV16 infection was not associated with atypical squamous cells of unknown significance (ASCUS), the only cytologic abnormality identified. Therefore, HPV16 was associated with OSCCs among individuals with accessible oropharyngeal lesions but not with cytologic evidence of dysplasia among high-risk individuals without such lesions. An oropharyngeal Pap-test equivalent may not be feasible, likely due to limitations in sampling the relevant tonsillar crypt epithelium. Cancer Prev Res; 4(9); 1378–84. ©2011 AACR.
HPV-associated Oropharyngeal Cancers—Are They Preventable?
Abstract
It is not known whether a human papillomavirus (HPV)-induced oropharyngeal precancerous lesion could be identified by screening with a pap test equivalent or whether one even exists. In this issue of the journal (beginning on page 1378), Fakhry and colleagues report their results showing that cytologic evaluation of the oropharynx, although useful in detecting invasive oropharyngeal cancers, may have limited utility as a screening modality for detecting precancer. These findings argue against the potential for secondary prevention of HPV-associated oropharyngeal cancers through screening for and preventing the progression of precancer and highlight the opportunity for primary prevention through prophylactic HPV vaccination, if proven efficacious and cost-effective. Cancer Prev Res; 4(9); 1346–9. ©2011 AACR.