Purpose/Rationale: To examine HPV testing, positivity, smoking status, and clinical presentation in a national sample of veterans with oropharyngeal cancer.
Background: HPV positivity confers a favorable prognosis in patients with oropharyngeal cancer. Some data suggest that smoking may influence prognosis in HPV+ patients. However, much of our understanding of HPV+ disease originates from single institution academic centers, which may not be representative of the veteran population with respect to smoking status and other features. Multiple de-escalation trials have recently been designed for HPV+ patients, and it is important to understand disease epidemiology in veterans to determine whether the findings will be generalizable to them.
Methods: We used the Veterans Affairs Central Cancer Registry to identify patients diagnosed with oropharyngeal cancer from 2010-2015. We quantified the frequency of HPV testing and positivity over time. We calculated smoking prevalence by HPV status. We then performed logistic regression to investigate associations between smoking status and presentation with T3/N2c or higher stage disease.
Results: For the 5,231 evaluable patients, rates of HPV testing increased from 20% in 2010 to 53% in 2015. Among the patients tested in 2015: 64% were high risk HPV+, 4% low risk HPV+, and 32% HPV−. Few patients were never smokers regardless of HPV status: 11% HPV− and 18% HPV+. Greater than one third (37%) of HPV+ and half (57%) of HPV− patients were current smokers. Current smoking was associated with an increased risk of presentation with American Joint Committee on Cancer 7 stage T3, N2c, or higher disease for both HPV+ (OR 1.48, P = .019) and HPV− patients (OR 2.14, P = .002).
Conclusions/Implications: HPV testing is increasing within the VA. Among tested patients, HPV positivity rates are comparable to that of the overall population. However, compared to a number of published trials that have established treatment outcomes in HPV+ patients, a larger proportion of veterans are current smokers. We found that smoking is associated with an increased risk of advanced primary tumor or nodal stage in veterans, regardless of HPV status. Efforts should be undertaken to increase HPV testing among veterans with oropharyngeal cancer in order to more reliably establish prognosis and understand the impact of smoking.
