Surgically treated oropharyngeal cancer: risk factors and tumor characteristics

To assess risk factors of patients with oropharyngeal squamous cell carcinoma in the Munich area of Southern Germany in relation to human papillomavirus (HPV) association of the tumors. To demonstrate differences in tumor characteristics and their impact on adjuvant treatment.

Between November 2010 and July 2013, patients were prospectively interviewed for risk factors before they underwent surgical resection of their tumors. HPV association was evaluated by p16 immunohistochemistry; tumor characteristics and type of adjuvant treatment were recorded. Follow-up data were collected after a median follow-up of 12.1 month.

In contrast to many recent studies, we could not detect any difference in overall age and age at sexual debut between p16-positive and p16-negative patients. P16-negative patients are characterized by a more intensive tobacco and alcohol use, a more abusive way of consumption, less nonoral and less oral sex partners. P16-positive patients had a significantly higher risk of lymph node metastases, but nevertheless a significant lower risk to recur or to die. No difference in the incidence of synchronous second primary tumors was seen. P16-positive patients generally received a more aggressive adjuvant treatment because of more frequently involved lymph nodes.

Lifestyle risk factors such as smoking, drinking, and sexual habits were independent from age, but showed marked differences between the p16-positive and p16-negative group. Since p16-positive patients were treated more aggressively, it is not possible to distinguish whether the better outcome of HPV-positive patients is a result of less aggressive cancers or more aggressive treatment. With regard to the ongoing debate about treatment deintensification, we should keep in mind that the survival of HPV-positive cancer patients is not 100 %.