Human Papillomavirus Testing in Head and Neck Squamous Cell Carcinoma: Impact of the 2018 College of American Pathologists Guideline Among Referral Cases at a Large Academic Institution

Context.— Given the growing clinical significance of human papillomavirus status in oropharyngeal squamous cell carcinoma, the College of American Pathologists established a set of evidence-based recommendations for high-risk human papillomavirus testing. Objective.— To evaluate the impact of the recommendations on human papillomavirus ancillary test ordering habits by comparing compliance before and after the guideline was published. Design.— We retrospectively reviewed head and neck squamous cell carcinoma biopsy or resection specimens from outside institutions during a 2.5-year period around guideline publication for whether or not human papillomavirus testing was performed in accordance with the guideline. Results.— Human papillomavirus testing deviated from the guideline in 45 of 107 cases (42.1%) before and 93 of 258 cases (36.0%) after their publication (P = .29). This included 6 of 26 cases of oropharyngeal squamous cell carcinoma (23.1%) before and 5 of 55 cases (9.1%) after (P = .16), with 5 of 5 (100.0%) after due to not performing p16 immunohistochemistry. This also included 30 of 68 cases of nonoropharyngeal carcinoma (44.1%) before and 69 of 163 (42.3%) after the guideline was published (P = .88), with 29 of 30 (96.7%) before and 67 of 69 (97.1%) after due to unnecessary use of p16 immunohistochemistry. Nodal metastasis testing deviated in 9 of 13 cases (69.2%) before and 19 of 40 cases (47.5%) after (P = .21) with marked variability in testing, including 3 of 9 (33.3%) before and 8 of 19 (42.1%) after, for not confirming certain p16 immunohistochemistry–positive tumors with human papillomavirus–specific testing. Conclusions.— Pathologists continue to deviate from the testing guideline significantly in everyday practice. Further education and discussion about the appropriate handling of head and neck cancer specimens may be needed.