Racial and ethnic disparities in nasopharyngeal cancer with an emphasis among Asian Americans

Abstract

Despite the overall decreasing incidence, nasopharyngeal cancer (NPC) continues to cause a significant health burden among Asian Americans (AAs), who are a fast-growing but understudied heterogeneous racial group in the United States. We aimed to examine the racial/ethnic disparities in NPC incidence, treatment, and mortality with a specific focus on AA subgroups. NPC patients aged ≥15 years were obtained from the Surveillance, Epidemiology, and End Results (SEER) 18 (1975-2018). AAs were divided into Chinese, Filipino, Vietnamese, Hawaiian, Japanese, Laotian, Korean, Cambodian, Indian/Pakistani and other Asian/Pacific Islanders (APIs). Age-adjusted incidence was calculated using the SEER*Stat software. Cox proportional and Fine-Gray subdistribution hazard models were used to calculate overall and cause-specific mortalities after adjusting for confounders. Among the total 11 964 NPC cases, 18.4% were Chinese, 7.7% Filipino, 5.0% Vietnamese, 1.2% Hawaiian, 1.0% Japanese, 0.8% Laotian, 0.8% Korean, 0.6% Cambodian, 0.5% Indian/Pakistani and 4.4% other APIs. Laotians had the highest age-adjusted NPC incidence (9.21 per 100 000), which was 18.04 times higher than it in non-Hispanic Whites (NHWs). Chinese and Filipinos observed lower overall mortalities, however, Chinese saw increased NPC-specific mortality than NHWs. Disparities in mortality were also found across different histology subtypes. This is the first and largest study examining the NPC incidence and outcomes in AA subgroups. The significant disparities of NPC within AAs underline the importance of adequate AA-subgroup sample size in future studies to understand the prognostic role of ethnicity in NPC and advocate more ethnically and culturally tailored cancer prevention and care delivery.

Keywords: Asian Americans; incidence; mortality; nasopharyngeal cancer; racial/ethnic disparities.