Genomic Profile of Chronic Lymphocytic Leukemia in Korea Identified by Targeted Sequencing.

Chronic lymphocytic leukemia (CLL) is extremely rare in Asian countries and there has been one report on genetic changes for 5 genes (TP53, SF3B1, NOTCH1, MYD88, and BIRC3) by Sanger sequencing in Chinese CLL. Yet studies of CLL in Asian countries using Next generation sequencing have not been reported. We aimed to characterize the genomic profiles of Korean CLL and to find out ethnic differences in somatic mutations with prognostic implications. We performed targeted sequencing for 87 gene panel using next-generation sequencing along with G-banding and fluorescent in situ hybridization (FISH) for chromosome 12, 13q14.3 deletion, 17p13 deletion, and 11q22 deletion. Overall, 36 out of 48 patients (75%) harbored at least one mutation and mean number of mutation per patient was 1.6 (range 0-6). Aberrant karyotypes were observed in 30.4% by G-banding and 66.7% by FISH. Most recurrent mutation (>10% frequency) was ATM (20.8%) followed by TP53 (14.6%), SF3B1 (10.4%), KLHL6 (8.3%), and BCOR (6.25%). Mutations of MYD88 was associated with moderate adverse prognosis by multiple comparisons (P = 0.055). Mutation frequencies of MYD88, SAMHD1, EGR2, DDX3X, ZMYM3, and MED12 showed similar incidence with Caucasians, while mutation frequencies of ATM, TP53, KLHL6, BCOR and CDKN2A tend to be higher in Koreans than in Caucasians. Especially, ATM mutation showed 1.5 fold higher incidence than Caucasians, while mutation frequencies of SF3B1, NOTCH1, CHD2 and POT1 tend to be lower in Koreans than in Caucasians. However, mutation frequencies between Caucasians and Koreans were not significantly different statistically, probably due to low number of patients. Collectively, mutational profile and adverse prognostic genes in Korean CLL were different from those of Caucasians, suggesting an ethnic difference, while profile of cytogenetic aberrations was similar to those of Caucasians.

Lymphoma and lymphoid leukemia incidence in Florida children: ethnic and racial distribution.

BACKGROUND: Incidence reports for pediatric lymphoma and lymphoid leukemia in Hispanic subpopulations in the United States are rare. The authors hypothesized that Florida's Hispanic children would have higher risks of lymphoma and lymphoid leukemia compared with non-Hispanic white children. METHODS: All cases of lymphoid leukemia, Hodgkin, non-Hodgkin, and Burkitt lymphoma (SEER International Classification of Diseases for Oncology codes) in children (< 15 years) in the Florida Cancer Data System (FCDS) from 1985 to 1997 were studied. Cases were classified as: 1) white, 2) Hispanic, or 3) black, and stratified by age. Age-adjusted rates for the three race-ethnic groups were calculated. Rates for Hispanics and blacks were compared with whites as standardized rate ratios (SRR) with 95% confidence intervals. RESULTS: Seven hundred thirty-one incident cases of pediatric lymphoma and 1231 cases of lymphoid leukemia were identified during the study period. For children with lymphoma, the SRR for Hispanics was 1.32 (95% CI, 1.20-1.44), and for blacks, the SRR was 0.68 (95% CI, 0.63-0.72. For lymphoid leukemia, the SRR for Hispanics was 1.29 (95% CI, 1.28-1.30), and for blacks, the SRR was 0.55 (95% CI, 0.54-0.56). Similar rates were found for the Hodgkin and non-Hodgkin subgroups. CONCLUSIONS: Incidences of Hodgkin and non-Hodgkin lymphoma were significantly higher in Florida's Hispanic children, with 30% increased relative risks, compared with whites. Black children had significantly decreased incidences and risk. Results for lymphoid leukemia were similar. Incidence of lymphoma in Florida's Hispanic children (primarily Cuban and Central American origin) differed from similar reports from Texas and California, where Hispanics are primarily of Mexican origin.

Large granular lymphocyte leukemia. A study of nine cases in a Chinese population.

Large granular lymphocyte (LGL) leukemia is a neoplastic disorder of lymphocytes that is characterized by the presence of prominent cytoplasmic granules, and involves the proliferation of at least two distinct cell types, T cells and natural killer (NK) cells. The authors report the clinical and pathologic features of 9 Chinese patients with LGL leukemia, who represented 14% of 64 cases of chronic lymphoproliferative disorders diagnosed at their centers in 3 years. Three different groups could be defined on immunophenotypic and clinical grounds. The first group of 4 cases were CD2+CD3+CD4-CD8+. With the exception of a pediatric case, these cases ran an indolent course that was similar to the T-cell LGL leukemia most common in Western patients. However, thrombocytopenia and pure red cell aplasia were more common in the patients in this study, which was similar to the experience in Japanese patients. The second group of two cases were CD2+CD3+CD4+CD8-, and appeared to have worse outcomes than the first group. The third group of 3 cases were CD2+CD3-CD4-CD8-CD56+. Although phenotypically similar to the NK-cell LGL leukemia reported in Western patients, these cases were clinically more aggressive than their Western counterparts. This study is the first to report comprehensively the different types of LGL leukemias in Chinese patients, and provides useful information on the similarities and similarities and differences of these disorders as compared to those cases in the West.

Racial differences in acute lymphocytic leukemia mortality and incidence trends.

Mortality and morbidity rates for childhood leukemia are examined with reference to time trends and racial differences. Prior to 1964, white and nonwhite children had very different acute lymphocytic leukemia (ALL) mortality rates. With the advent of successful chemotherapy, the mortality rate of ALL in white children has decreased resulting in virtually no racial differences in ALL mortality. The reasons for a stable ALL mortality rate in nonwhite children despite successful chemotherapy include poor access to health care, undefined socioeconomic factors and a biologically different type of ALL occurring in nonwhite children. Recent data from two cancer surveys (1969-1971, 1973-1976) reveal that nonwhite children have a lower incidence of ALL than white children. Underreporting in the nonwhite children could partly account for the difference, but other contributing factors might include a genetic predisposition, undefined socioeconomic influences, and perhaps, a viral agent. Further studies of the factors contributing to racial differences in ALL incidence and mortality are needed.