Comparison of human papillomavirus in situ hybridization and p16 immunohistochemistry in the detection of human papillomavirus-associated head and neck cancer based on a prospective clinical experience.

BACKGROUND

Human papillomavirus (HPV) is a causative agent in a subset of head and neck squamous cell carcinomas (HNSCCs). These HPV-related cancers have a clinicopathologic profile that diverges from HPV-negative HNSCCs. Accordingly, HPV testing may soon become integrated into standard pathologic assessment of HNSCCs.

METHODS

Data were prospectively collected for all patients with head and neck carcinomas who had undergone HPV testing at the Johns Hopkins Hospital as part of clinical care during a 57-month period. HPV testing consisted of concurrent HPV16 in situ hybridization (ISH) and p16 immunohistochemistry (IHC). Wide spectrum HPV ISH was reserved for p16-positive cases that were HPV-16 negative.

RESULTS

HPV analysis was performed on 256 head and neck carcinomas in an effort to predict clinical outcomes (56%), localize primary tumor origin (21%), establish tumor classification (9%), determine patient eligibility for vaccine trials (8%), or satisfy patient curiosity (5%). A total of 182 (71%) tumors were HPV positive. HPV positivity correlated with oropharyngeal site (82% vs 9%) and male sex (77% vs 48%). p16 positivity was present in all 176 HPV16-positive cases, and in 19 of 80 (24%) cases that were HPV-16 negative. In 6 (32%) discordant cases, p16 expression was because of the presence of another HPV type.

CONCLUSIONS

A feasible strategy that incorporates p16 IHC and HPV ISH is able to detect HPV in a high percentage of oropharyngeal carcinomas. HPV status is frequently requested by the oncologist to estimate clinical outcome, and used by pathologists to establish tumor classification and determine site of tumor origin.