Racial differences in acute lymphocytic leukemia mortality and incidence trends

Enhanced T cell lymphoma in NOD.Stat5b transgenic mice is caused by hyperactivation of Stat5b in CD8+ thymocytes

Activation of signal transducers and activators of transcription (STAT) proteins may be critical to their oncogenic functions as demonstrated by the development of B-cell lymphoma/leukemia in transgenic (TG) mice overexpressing a constitutively activated form of Stat5b. However, low incidence of CD8⁺ T cell lymphoma was observed in B6 transgenic mice overexpressing a wild-type Stat5b (B6.Stat5b^Tg) despite of undetectable Stat5b phosphorylation and the rate of lymphomagenesis was markedly enhanced by immunization or the introduction of TCR transgenes [1]. Here, we report that the wild-type Stat5b transgene leads to the acceleration and high incidence (74%) of CD8⁺ T cell lymphoblastic lymphomas in the non-obese-diabetic (NOD) background. In contrast to the B6.Stat5b^Tg mice, Stat5b in transgenic NOD (NOD.Stat5b^Tg) mice is selectively and progressively phosphorylated in CD8⁺ thymocytes. Stat5 phosphorylation also leads to up-regulation of many genes putatively relevant to tumorigenesis. Treatment of NOD.Stat5b^Tg mice with cancer chemopreventive agents Apigenin and Xanthohumol efficiently blocked lymphomagenesis through reduction of Stat5 phosphorylation and genes up-regulated in the NOD.Stat5b^Tg mice. These results suggest that NOD genetic background is critical to the Stat5b-mediated lymphomagenesis through regulation of Stat5 hyperactivation. NOD.Stat5b^Tg mouse is an excellent model for studying the molecular mechanisms underlying lymphomagenesis and testing novel chemoprevention strategies.

Bloodstream infections in home infusion patients: the influence of race and needleless intravascular access devices

OBJECTIVES

To determine the cause of increased central venous catheter-associated (CVC) bloodstream infection (BSI) rates in a cohort of pediatric hematology /oncology patients receiving home health care (HHC).

METHODS

A retrospective cohort study of hematology/oncology patients with CVCs receiving HHC from January 1992 through November 1994.

RESULTS

Of 182 patients with CVCs identified during the study period, 58 (32%) acquired 90 BSIs during 75,085 CVC days. BSI rates increased significantly from 1992 through 1994 (0.8 vs 1.0 vs 1.7 BSIs per 1000 CVC days; p < 0.005). Known risk factors, including catheter type, patient age less than 5 years, sex, or diagnosis, were not associated with increased BSI rates. After introduction of needleless devices for CVC access to the HHC regimen in May 1993, BSI rates increased 80% (from 0.81 to 1.46 BSIs/1000 CVC days, relative risk 1.8; p < 0.02). The only other significant risk factor was the race of the patient. White children had the lowest BSI rate before and after needleless-device introduction (0.4 vs 0.9 BSIs/1000 CVC days; p > 0.1), whereas black patients had the highest, unaffected by the introduction of these devices (2.5 BSIs/1000 CVC days). Both Hispanic (0.5 vs 1.6 BSIs/1000 CVC days) and Asian-American children's (0.4 vs 1.5 BSIs/1000 CVC days) BSI rates increased threefold and fourfold after the introduction of needleless devices.

CONCLUSIONS

Our data suggest that pediatric hematology/oncology patients receiving HHC via needleless devices may have an increased risk of BSIs, and this risk may vary by race. We hypothesize that prevention of BSIs may require consideration of cultural, ethnic, and language differences when parents are trained to provide care for their children with CVCs in the home.

Small influence of parental educational level on the survival of children with leukaemia in The Netherlands between 1973 and 1979

We studied the effect of parental educational level (PEL), an indicator of socio-economic status (SES), on survival of children with acute lymphoblastic (ALL) and non-lymphoblastic leukaemia (ANLL). All children with ALL and ANLL diagnosed in The Netherlands in the period 1973-1979, registered by the Dutch Childhood Leukaemia Study Group and followed until 1991 were included. Bone marrow and blood smears had been uniformly classified in a central laboratory; cases with acute lymphoblastic leukaemia (ALL) were subdivided into standard risk (SR) and high risk (HR). PEL, assessed as a risk indicator in a separately conducted population-based case-control study of the same children (response rate: 88%), was divided into low, when neither of the parents had more than elementary school or lower vocational education, and high when either had more. Children with SR ALL of high PEL parents had a slightly higher 10-year survival rate than of low PEL parents (58% versus 54%, P = 0.25), whereas survival for the latter increased more (P = 0.06) from a lower level in the period 1973-1975. However, children of low PEL parents with HR ALL and ANLL had a higher 10-year survival rate compared with children of high PEL parents (P = 0.10 and 0.22, respectively). Children without information on PEL, non-responders, migrants and with missing values exhibited slightly worse survival rates. The influence of PEL on survival of acute leukaemia in children in The Netherlands during 1973-1979 appeared small or even equivocal. Small differences in SES and optimal geographic and financial access to care, delivered through national treatment protocols, may be responsible for these results.

Childhood Leukaemia: Is it a Problem in Tropical Africa?

This is a report on the frequency and biogical aspects of childhood leukaemia in tropical Africa based on experience from Kenya and the literature. Out of the 934 cases of leukaemia diagnosed, treated and followed up at Kenyatta National Hospital between 1976 and 1985, 347 occurred in children below the age of 15 years and comprised 37% of leukaemia in all ages. Childhood acute leukaemia formed 52.3% of all the acute leukaemias. Acute non-lymphocytic (ANLL) and acute lymphocytic leukaemias (ALL) occurred. in almost equal proportions 42 % and 46 % respectively. FAB ANLL, M4 and FAB, ALL, L1 subtypes predominated although ALL, L2 (45%) was encountered almost as frequently as ALL, L1 (50%). The acute leukaemias had a peak occurrence in the 5-9 age group at a median frequency of 41 74. These observations are generally true for childhood leukaemia patterns in sub-Saharan Africa. T-cell ALL phenotype was the most commonly diagnosed, being 46'x of ALL. Clinically advanced disease, severe malnutrition and common ocular chloromata were notably prominent. Remission induction and survival results were noted to be inferior to those obtained in Western countries and are attributed to the presence of many risk factors and unsatisfactory management facilities.

Incidence trends and ethnic patterns for childhood leukaemia in Hawaii: 1960-1984

We analysed data obtained from the Hawaii Tumor Registry, a population-based participant in the Surveillance, Epidemiology, and End Results (SEER) programme that monitors cancer incidence and mortality for the entire state. A total of 138 males and 116 females, under the age of 15, were diagnosed with leukaemia between 1960 and 1984, with average annual age-adjusted incidence rates of 49.6 and 44.8 per million, respectively. Time trend analysis by 5-year calendar periods revealed an increasing rate for leukaemia among females only, whereas other populations have shown a positive trend in both sexes. The incidence rates for all ethnic groups combined were similar to those for US whites. Japanese and Chinese males had a slightly higher rate for leukaemia than US whites, while Filipinos, Hawaiians and whites in Hawaii had relatively lower rates. Among females, incidence was higher among whites, Filipinos, Hawaiians and Chinese than among US whites, and lower among Japanese. Thus, there were notable sex differences in the ethnic distribution of this disease.