Head and neck squamous cell carcinomas among males of the three largest Asian diasporas in the US, 2004–2013

1

Introduction

Approximately 58 % of the global Head and Neck Squamous Cell Carcinoma (HNSCC) cases are in Asia [ 1 ], with a large proportion occurring in South Asia. Oral Cavity Cancer (OCC) is the most common cancer in males in the South Asian countries of India, Pakistan, and Sri Lanka [ 2 ]. In India [ 1 ] and Pakistan [ 3 , 4 ], head and neck cancers contribute 30 % and 21 % of all cancer cases in males, respectively. Although nasopharyngeal is the 11th most common cancer [ 5 ] in China, it is a rare disease in rest of the world. In certain parts of Southern China, nasopharyngeal cancer incidence is 20–50 times higher than the global average [ 6 , 7 ]. Similarly, head and neck cancers are the third most common cancer in the Philippines [ 8 ]. In contrast to these Asian countries, HNSCCs in the US represent less than six percent of all new cancer diagnoses among males [ 9 ] making it the eighth most common cancer in males [ 10 , 11 ].

According to the US Census Bureau, Chinese, Asian Indian and Filipino are the three largest Asian groups in the US, accounting for more than 62 % of the total Asian population. [ 12 ] Between 2000 and 2017, the US Asian population increased by 88 %, making it the fastest growing racial group. Among Asian Indians, the increase during this period was 131 %, 85 % for Chinese and 67 % for Filipinos (based on the population reported in US Census [ 13 ] and American Community Survey [ 12 ]). Notably, the risk of HNSCCs in these Asian diasporas in the US is unknown. Reporting the rates for Asians as a group presents an incomplete picture as Asians are not homogeneous [ 14 ]. Apart from the cultural and genetic differences, the baseline rates in various Asian countries differ.

Risk factors for HNSCC have been identified, and rates vary by site group in the countries of origin. Certain risk factors have been strongly linked to specific sites, such as Epstein Barr Virus [ 5 , 15 ] and salt-cured foods [ 6 ] with nasopharyngeal cancer, Human Papillomavirus with oropharyngeal cancer (OPC) [ 16 ], areca nut with OCC [ 4 , 17 , 18 ], while tobacco and alcohol consumption have been found to be associated with multiple HNSCC sites [ 192021 ]. Studies from the United Kingdom (UK) and Australia have shown that South Asian diasporas have higher rates of HNSCCs than these countries’ general populations [ 17 , 18 , 222324 ]. Moreover, these South Asian diasporas engage in high-risk behaviors (e.g., areca nut use) post migration [ 25 ]. Studies have also shown that the risk of nasopharyngeal cancer continues to be higher in Chinese even after migration to other countries [ 22 , 24 ]. It is unknown whether similar incidence rate patterns and risk factors exist in the US diaspora.

The primary purpose of this study was to examine the characteristics, such as site group and stage at diagnosis, of male HNSCC cases among the three largest Asian subpopulations in the US and compare them to Non-Hispanic Whites (NHWs). The secondary purpose was to explore the temporal trends by site group and subsite. This work will provide a new perspective on how Asians immigrating to the US fare in terms of HNSCCs.