Changes in the Incidence and Human Papillomavirus-Positive Portion of Oropharyngeal Squamous Cell Carcinoma in Hong Kong

Simple Summary Oral infection with high-risk human papillomaviruses is one of the known risk factors for oropharyngeal cancer. Human papillomavirus-related oropharyngeal cancer is a rising trend in many Western countries. Hong Kong is a vibrant Chinese cosmopolitan city in East Asia where data on the trend of change in human papillomavirus-related oropharyngeal cancer are not available. This study found that oropharyngeal cancer cases have increased persistently over the last three decades in Hong Kong, despite a notable decrease in other head and neck cancers such as the laryngeal cancer. By testing a series of cancer samples collected over the past several years, this study found that the proportion of oropharyngeal cancer infected with high-risk human papillomaviruses has increased substantially over the last decade. Strategies to prevent oral human papillomavirus infection and its associated diseases including oropharyngeal cancer are urgently needed. Research on the early detection of oropharyngeal cancer is a priority.Abstract The incidence of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is rising in the West, but little is known in Asia. This study elucidated changes in the incidence and HPV-positive portion of OPSCC in Hong Kong. Data from population-based cancer registry were used to analyze the incidence of OPSCC in association with other head and neck cancers. Archived tumor tissues were tested for HPV. From 1986 to 2020, there was a marked decrease in the incidence of nasopharyngeal and laryngeal cancers, but a persistent increase in OPSCC from 36 cases in 1986 to 116 cases in 2020. The average positive rate for high-risk HPV was 36.1% (112/310) among OPSCC diagnosed in 2010-2020. The HPV-positive rate in recent years was significantly higher than earlier cases (tonsil SCC: 64.7% (55/85) in 2016-2020 vs. 40.4% (19/47) in 2010-2015, p = 0.007). Patients with HPV-positive tonsil cancers were significantly younger than those negative (mean [SD]: 58.9 [9.9] vs. 64.3 [13.3] years, p = 0.006), but no significant difference was observed between genders. A persistent increase in the incidence of oropharyngeal cancer over the last few decades was observed in Hong Kong, which can be explained by the remarkable increase in HPV-positive tonsil cancers.