Emergence of HPV16-positive oropharyngeal cancer in Black patients over time: University of Maryland 1992-2007

Abstract

While we previously reported a striking racial difference in the prevalence of human papilloma virus (HPV)-positive squamous cell carcinoma of the oropharynx (OPSCC), less is known about differences in outcomes and trends over time in OPSCC by HPV status and race. We conducted a retrospective analysis of 467 patients with OPSCC treated at the University of Maryland Greenebaum Cancer Center (Baltimore, MD) between 1992 and 2007, of which 200 had tissue available for HPV16 testing. HPV16-positive patients were significantly more likely to be white, with 45.5% of whites and 15.5% of blacks testing positive for HPV16. There was a significant increase in HPV16-positive OPSCC for all patients over time from 15.6% in 1992 to 1995 to 43.3% in 2004 to 2007 (P = 0.01). From 1992 to 1995, 33% of white patients were HPV16-positive, with no black patients positive. From 2004 to 2007, 17.7% of black patients and 54% of white patients were HPV16-positive. White and black patients with HPV16-positive tumors had an identical and favorable overall survival (OS; median, 8.1 and 8.1 years, respectively). However, among HPV16-negative patients, whites had an improved OS compared with blacks (median, 2.3 vs. 0.9 years, respectively; P = 0.02), including when analyzed in a multivariable Cox regression model. From 1992 to 2007, the percentage of HPV16-positive OPSCC increased for white patients and was seen for the first time in black patients. While survival for HPV-positive black and white patients was similar and favorable, outcomes for HPV-negative patients were poor, with blacks having worse survival even after controlling for baseline characteristics.

Figure 1

Changes in Percentage of HPV Positive Oropharyngeal Cancers over Time by Race * ^ * P-values Listed are for Comparison of Change in Percentage of HPV Positive OPSCC between 1992 and 2007 for Black, White and Black and White Patients together ^ Percentage of HPV16 positive patients (Total number of HPV positive patients/total number of patients during time period) by race over each time period shown below graph

Figure 2

Overall Survival Functions A. Kaplan-Meier Estimates of Overall Survival According to Ethnic Group in HPV 16 Positive Patients. B. Kaplan-Meier Estimates of Overall Survival According to Ethnic Group in HPV 16 Negative Patients. C. Kaplan-Meier Estimates of Overall Survival According to HPV Status in White Patients. D. Kaplan-Meier Estimates of Overall Survival According to HPV Status in Black Patients. *Overall Survival Profiles were truncated at 8 years