Abstract 5207: Comparison of subtype-specific incidence rates of lymphoid malignancies in Hong Kong and the United States

Abstract

Abstract Clinical studies of lymphoid malignancies (LMs) have suggested that the descriptive patterns of these neoplasms differ in East Asia compared to Western populations. However, there are very limited available data on population-based, subtype-specific incidence rates of LMs in the East Asian population, particularly in Chinese. Using data from the Hong Kong (HK) Cancer Registry and the United States (U.S.) Surveillance, Epidemiology, and End Results Program, we calculated and compared age-adjusted incidence rates of LM subtypes in HK to those in Whites and Asians living in the U.S. Overall and sex-specific rates were calculated for the period 2001-2010. In order to formally compare the incidence rates between HK and the U.S., standardized rate ratios (SRRs) were calculated comparing the age-adjusted rates of each subtype for U.S. Whites and U.S. Asians in the SEER 13 database to HK. The incidence of most subtypes was low in the HK population, with rates <1 case per 100,000 for all subtypes except for diffuse large B-cell lymphoma (3.26/100,000) and plasma cell neoplasms (1.99/100,000). Age-adjusted incidence rates of all evaluated B-cell subtypes were significantly higher in U.S. Whites compared to HK, with SRRs ranging from 1.6 (Burkitt lymphoma) to 9.1 (chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)). Rates in U.S. Asians were generally intermediate to those in U.S. Whites and HK, with SRRs for B-cell subtypes ranging from 1.0 (Burkitt) to 2.0 (CLL/SLL) comparing Asians in the U.S. to HK. For T or NK-cell subtypes, rates of extranodal NK/T-cell lymphoma were significantly lower in both U.S. Whites (SRR = 0.2) and U.S. Asians (SRR = 0.5) compared to HK. However, incidence rates of other evaluated T-cell subtypes were comparable or slightly higher in the U.S. population compared to HK. Our findings, which are based on data from population-based disease registries, provide new insight into the subtype-specific patterns of LMs in the Chinese population, and suggest the need for etiological studies of LMs in the East Asian population to elucidate the factors responsible for these differences in the geographic incidence patterns. Citation Format: Nathaniel Rothman, Bryan A. Bassig, Wing-Yan Au, Oscar Mang, Roger Ngan, Lindsay M. Morton, Dennis K.M. Ip, Wei Hu, Tongzhang Zheng, Wei Jie Seow, Jun Xu, Qing Lan. Comparison of subtype-specific incidence rates of lymphoid malignancies in Hong Kong and the United States. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5207.