Abstract A071: Characterization of head and neck squamous cell carcinoma from Jamaican patients using p16 immunohistochemistry and HPV polymerase chain reaction in archival formalin-fixed, paraffin-embedded tissues

Abstract

Abstract CDKN2A (p16) expression is a well-established prognostic marker and its loss is a common molecular feature in tobacco/alcohol-associated head and neck squamous cell carcinoma (HNSCC). Over the past two decades evidence has also suggested that high-risk human papilloma virus (HR-HPV) infection, which results in overexpression of p16, is implicated in the development of some HNSCC. HNSCC is the sixth most common cancer worldwide and the seventh in Jamaica. Mortality rates for HNSCC in the Caribbean is among the highest in the world. This study will for the first time examine the molecular features of HNSCC as it relates to p16 expression and HPV in patients from Jamaica. There were no previous studies of this kind conducted in the English-speaking Caribbean. Methods: This retrospective cohort study was conducted using archival formalin-fixed paraffin-embedded tissue from patients diagnosed with HNSCC at the Department of Pathology, University of the West Indies, and the National Public Health Laboratory from 2001-2010. Clinical information was extracted for all patients. P16 immunohistochemistry was performed using P16INK4A clone E6H4 mouse anti-human protein and identification of HR-HPV DNA was done by standard PCR using MY09/MY11 consensus primers of the L1 HR-HPV gene. Results: The study population consisted of 326 HNSCC cases with ages ranging from 18 to 92 years (mean, 65 yrs. ± 15 SD). There were 254 males, 63 females and 9 of unknown sex with M: F ratio of 4:1. The majority of tumors were either moderately differentiated 147/326 (45%) or were poorly differentiated 55/326 (17%). All cases were tested for p16, and the majority 255/326 (78.22%) were negative and 71/326 (21.8%) were positive. All p16+ cases along with a subset of 60 randomly selected p16- cases were tested for HR-HPV by PCR. There were nine p16+ cases which were also positive for HR-HPV DNA. HPV 16 was detected in all cases, one case had HPV16 and 18, and another had HPV 16, 18, 39, 68 and 73. None of the sixty p16- cases were positive for HR-HPV. The nine patients that were HR-HPV+ and p16+ had a mean age of 61 yrs. ± 15 SD (range 39-83 years) with a M: F ratio of 8:1. All patients had moderately differentiated tumors, and the majority (78%) of these was from non-oropharyngeal sites with predominance in the larynx. Conclusion: In Jamaica, the prevalence of HPV-related HNSCC appears to be low with the majority of patients showing no expression of p16 and diagnosed in older individuals. Based on what is known in the literature, our study results suggest that in Jamaica most patients are diagnosed with alcohol and tobacco driven disease. The role of HPV in HNSCC warrants further investigation in this population. Citation Format: Sharon R Harrison, Carlos Tl Escoffery, Sheray Chin, Norma D McFarlane-Anderson, Marvin E Reid, Camille C Ragin. Characterization of head and neck squamous cell carcinoma from Jamaican patients using p16 immunohistochemistry and HPV polymerase chain reaction in archival formalin-fixed, paraffin-embedded tissues [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A071.