Does prolonged breastfeeding reduce the risk for childhood leukemia and lymphomas?

AIM

Prolonged breastfeeding was shown to reduce the risk of childhood acute leukemia. The aim of the study was to investigate the protective effect of longer breastfeeding on the risk of lymphoid malignancies in children and its dependent socio-economic factors.

METHODS

The study group comprised of 169 patients with acute lymphocytic leukemia (ALL), Hodgkin's (HL) and non-Hodgkin's lymphoma (NHL), age =or<15 years, and 169 healthy controls, matched to patients by age and sex. Mothers of all study subjects provided information via telephone about the history of breastfeeding and parameters seen as proxies for viral infection.

RESULTS

The mean age+/-SD of cases was 5.44+/- 3.29 years and of control subjects 5.51+/-3.62 years. The male/female ratio was 1.73. Overall, the mean number of months of breastfeeding in the male patients and controls was 9.1 (95% confidence interval [CI] 7.9-10.4) and 12.1 (95% CI 11.0-13.4), respectively (P<0.001), and in the female patients and controls 8.4 (95% CI 6.9-10.1) and 11.5 (95% CI 10.0-13.0), respectively (P<0.01). In 103 ALL patients, a shorter period of breastfeeding (0-6 months duration), was associated with increased odds ratio (OR) for males (OR=3.1, 95% CI 1.4-6.8) and females (OR=2.2, 95% CI 0.8-6.32) as compared to breastfeeding longer than 6 months. In 103 ALL patients, 32 HL and 34 NHL patients, there were no statistically significant differences in the duration of breastfeeding between the male and female patients and their respective controls. In multivariate analysis, statistically significant risk factors for the development of childhood lymphoid malignancy were: a shorter duration of breastfeeding, lower age and level of education of mother and higher income, larger size of accommodation and birth order in the family.

CONCLUSION

The current study confirmed that a longer duration of breastfeeding has protective effect against ALL and HL. Additional factors found to be associated with an elevated risk of lymphoid malignancy were low age and low education of mother. All these factors can be related to an increased risk of early childhood infections.

Factors affecting the outcome of stem cell transplantation from unrelated donors for childhood acute lymphoblastic leukemia in third remission

Between July 1990 and March 2002, 35 consecutive children with ALL in third complete remission (CR3) underwent stem cell transplantation (SCT) from unrelated donors (UD). All patients received CAMPATH-1M 5-20 mg daily for 5 days. Grafts were T-cell depleted in 30 patients, 29 by CAMPATH antibodies and one by CD34 selection. Median follow-up was 3.8 years (0.3-9.3). Event-free survival (EFS) at 3 years was 35% (SE 8%); relapse rate and transplant-related mortality (TRM) at 3 years was 42 and 23%. Short first complete remission (CR1) <2.5 years was associated with lower EFS (P=0.001), higher TRM (P=0.019) and higher relapse rate (P=0.023). Short second complete remission (CR2) <2.5 years was associated with lower EFS (P=0.003) and higher TRM (0.009). Higher relapse rate and lower EFS were associated with isolated first extramedullary relapse (P=0.019, 0.012). There was no significant difference in outcome between mismatched unrelated donor stem cell transplantation (MMUD-SCT) and matched unrelated donor stem cell transplantation (UD-SCT). We conclude that UD-SCT is an effective treatment of ALL in CR3. The outcome remains limited by TRM and a high relapse rate. Short duration of CR1 and of CR2 and extramedullary site at first relapse are particularly adverse. MMUD should also be considered in high-risk patients, since the outcome of MMUD appears similar to MUD.

The changing pattern of bloodstream infection in pediatric oncology patients in the United Arab Emirates

A surveillance study was performed on the pattern and antimicrobial susceptibilities of microorganisms isolated from blood cultures in the main pediatric oncology unit in the United Arab Emirates. The only previous data were published in 1995. During 1998-2000, the pattern of bloodstream infection changed. Enterobacter spp. and Enterococcus spp. emerged as frequent pathogens, while Pseudomonas aeruginosa became less common. There was a high incidence (65/198) of polymicrobial bacteremia not previously reported. This study highlights the need for continuous surveillance of the pattern of bloodstream infection in pediatric oncology patients so that changes may be detected and antimicrobial treatment modified appropriately.

Growth and endocrine function in children with acute myeloid leukaemia after bone marrow transplantation using busulfan/cyclophosphamide

Longitudinal studies of growth and endocrine function of children with AML transplanted with BUCY are limited. We report a cohort of 23 children with AML transplanted (15 autologous and eight allogeneic) following a single chemotherapy protocol and surviving at least 2 years after BMT. Busulfan was given as a single daily dose. Growth and endocrine function was evaluated yearly from one up to 10 years post transplant (median 4.9 years). The mean height standard deviation score (HtSDS) of the entire group decreased from 0.01 (s.e.m. +/- 0.25) at diagnosis to -0.38 (+/- 0.28) at BMT (P = 0.001). There was no statistically significant difference between HtSDS at BMT and yearly HtSDS from 1 to 5 years post BMT. There was no significant relationship between age at BMT and subsequent change in HtSDS. To date, five of six girls have needed sex steroid replacement. Six of 12 evaluable boys had abnormal gonadotrophins, but none required sex steroid replacement. Children with AML who undergo BMT with BUCY show no significant growth impairment, but gonadal dysfunction is prominent, particularly in girls. Bone Marrow Transplantation (2000).

Effects of recombinant interferon-gamma and interleukin-2 on the generation of lymphokine-activated killer cells in vitro

In order to determine if recombinant interferon-gamma (rIFN-gamma) can augment the effect of recombinant interleukin-2 (rIL-2) in generating lymphokine-activated killer (LAK) cells, we have incubated normal peripheral blood mononuclear cells (PBMC) with these lymphokines for 3 days and then tested their LAK and natural killer (NK) cell activity. We have found that LAK activity in PBMC from 13 out of 13 normal donors was increased by the combined lymphokines above that due to either lymphokine alone, provided that rIL-2 was present at suboptimal concentration: Optimal levels of rIFN-gamma (100 U/ml) were able to enhance the LAK-inducing activity of suboptimal levels (5 U/ml) but not optimal levels (100 U/ml) of rIL-2. NK activity showed a similar response to these concentrations of lymphokines. Activation of LAK/NK cells was accompanied by increases in the percentages of Leu 19+ (CD56) cells and TAC+ (IL-2-receptor) cells, and in the intensity of TAC antigen expression. These results indicate that combination rIFN-gamma and rIL-2 may be more effective in generating LAK/NK cells than rIL-2 alone, particularly with suboptimal concentrations of rIL-2 such as occur during continuous infusion therapy with this agent.