Subtype-specific patterns of peripheral T-cell lymphoma in diverse Asian populations

Peripheral T-cell lymphomas (PTCLs) are rare, aggressive non-Hodgkin T-cell lymphomas with a poor prognosis. Black individuals have a higher incidence compared to White individuals, but little is known about incidence rates for specific Asian populations. We obtained average annual age-adjusted incidence rates (AAIR)/100,000 based on the age distribution for the US 2000 Census for PTCL-not otherwise specified (ICD-O-3: 9702), angioimmunoblastic T-cell lymphoma (AITL, 9705), and anaplastic large cell lymphoma (ALCL, 9714) within Asian subpopulations, in addition to rate ratios(RR) comparing racial/ethnic groups with non-Hispanic whites (NHW) as a reference group. Data was obtained from the Surveillance, Epidemiology, and End Results (SEER) 9 registry (1990-2014). The combined-subtype analysis showed no significant difference between Asian-Pacific Islanders overall and NHW (RR 0.94; p=0.0976), but stratified analysis in SEER showed striking differences. Southeast Asians had the highest incidence rates, followed by Filipinos, while Chinese had the lowest incidence rates (Table 1). By subtype, Southeast Asians had the highest incidence rates of PTCL-NOS (0.72/100,000, RR= 2.40, p=0.002, based on 21 cases), followed by Filipinos (0.45/100,000, RR=1.49, p<0.001). Both Filipinos (p=0.0004) and Vietnamese (p=0.05) had higher incidence rates of AITL (0.18/100,000) compared to NHW (0.1/100,000) with RR=1.73. NHW had the highest incidence rates of ALCL (0.23/100,000). Compared to NHW, Chinese, Japanese, and Koreans showed significantly lower ALCL rates (RRs = 0.45-0.57, p < 0.01). These findings highlight distinct subtype-specific PTCL risk patterns across Asian subgroups. Given the low case counts, results should be interpreted cautiously. Disaggregation of Asian subgroups in PTCL subgroups remains essential to identify high-risk groups and improve prognostic accuracy. Table 1. AAIR and RR for PTCL by racial/ethnic group. AAIR/100,000 95% CI N Rate Ratio 95% CI P-value Non-Hispanic Whites 0.63 0.62. 0.65 6,778 1.0 Chinese 0.50 0.43, 0.59 171 0.80 0.68, 0.93 0.0031 Japanese 0.60 0.51, 0.71 141 0.96 0.80, 1.13 0.6544 Filipino 0.80 0.71, 0.91 260 1.27 1.12, 1.44 0.0004 Korean 0.51 0.39, 0.65 64 0.80 0.61, 1.03 0.0932 Vietnamese 0.73 0.58, 0.92 87 1.16 0.91, 1.45 0.2260 Pacific Islander 0.73 0.54, 0.96 54 1.16 0.86, 1.52 0.3385 SE Asian 0.94 0.59, 1.41 28 1.49 0.94, 2.23 0.0882