Presence of human papillomavirus (HPV) in unknown primary squamous cell carcinoma (UPSCC) of the head-and-neck at initial presentation focuses on primary tumors of the oropharynx. The trends, frequency, and detection rate of UPSCCs have not previously been evaluated in the context of HPV tumor status. To determine the frequency of UPSCC over time and to evaluate the proportion of HPV-positive UPSCCs, authors [reference below] conducted a retrospective, single-institutional case series of patients diagnosed with UPSCC and evaluated at the Johns Hopkins Hospital from 1 January 1 2005 to 1 June 1, 2014. HPV status was determined by p16 immunohistochemical analysis and/or high-risk HPV DNA by in situ hybridization as clinically available.
Eighty-four UPSCC cases were eligible for analysis. The mean age of the patients was 57.3 years (range 29-80 years), and 88.1% (n = 74) were male. The frequency of UPSCC increased significantly over time (P for trend = .01) and was significantly higher during later calendar periods (14 cases during 2005-2008; 39 cases 2012-2014, P = .03).
A total of 69 cases (90.7%) with available HPV tumor status were HPV-positive. Patients with HPV-positive UPSCC were significantly more likely to be male (91% vs 42.9%, P = .005) and younger (56.1 vs 67.7 years, P = .002) than HPV-negative patients with UPSCC.
Authors concluded that frequency of UPSCC has increased significantly in recent calendar periods, and most cases are HPV-positive. As expected, patients with HPV-positive UPSCC tend to be male and younger.
JAMA Otolaryngol Head Neck Surg. doi:10.1001/jamaoto.2015.3228