Heterogeneity in head and neck cancer incidence among black populations from Africa, the Caribbean and the USA: Analysis of cancer registry data by the AC3

1

Introduction

Head and neck cancer (HNC) is the 6th most common cancer in the world [1] but the annual incidence rates (IR) vary substantially across geographical regions 234 . Tobacco smoking and alcohol drinking are the major risk factors of oral cavity, hypopharyngeal and laryngeal cancer 567 ; while, the human papillomavirus (HPV) is a prominent risk factor for oropharyngeal cancer and has been linked to other HNC sites 891011 . In addition, other viral factors such as Epstein-Barr virus (EBV) and HIV are associated with HNC risk notably, nasopharyngeal cancer 121314 , in areas where these viruses are more prevalent [101215] .

Incidence rates of HNC are particularly high in North America and Europe; and they are increasing rapidly in developing countries [416] . In 2016, the age standardized incidence rates for HNC per 100,000 men and women for cancer of the oral cavity, pharynx and larynx (HNC) were 11.2 for Europe and 10.1 for North America; whereas, rates were lowest in Latin American and the Caribbean, and in Africa (7.0 and 4.8 respectively) [17] . Despite lower incidence rates of HNC in the Caribbean and African populations, the mortality remains high. Most Caribbean and African countries are developing countries and are particularly vulnerable to poor cancer outcomes due to lack of access to care, late presentation and few resources for treatment [1819] . Therefore, it is important to produce relevant information on the epidemiological trends to inform cancer prevention in these countries before the HNC incidence transitions to that of the developed world. Few studies have investigated HNC incidence among blacks living in various geographical regions (USA, Caribbean and Africa), who differ substantially in terms of genetics, culture and environmental exposures 202122 . In addition, global surveillance data for most Caribbean countries are based on estimates from neighboring countries [17] . Comparative analyses among populations may provide clues on risk factors which can be further investigated in etiological studies to enhance prevention strategies in these regions.

The aim of our study was to compare for the first time, incidence rates and characteristics of HNC in black populations of Africa the Caribbean and the USA, using data from population-based cancer registries (PBCR).