Pregnancy, maternal exposure to analgesic medicines, and leukemia in Brazilian children below 2 years of age.

Childhood leukemia etiology, and mainly the interactions of genetic and environmental risk factors, remains largely unexplored. This national hospital-based case-control study was carried out in Brazil among children aged 0-23 months who were recruited at cancer and general hospitals in 13 states. Maternal medicine intake during pregnancy, including analgesic intake, was assessed by face-to-face interviews with the mothers of 231 leukemia patients and 411 controls. Unconditional logistic regression was used to ascertain crude and adjusted odds ratios (ORs), and their 95% confidence intervals (CIs) for the association between maternal analgesic use during pregnancy and early age leukemia. Acetaminophen use during the first trimester of pregnancy showed an OR=0.39 (95% CI 0.17-0.93) for acute lymphocytic leukemia and an OR=0.37 (95% CI 0.16-0.88) for use in the second trimester. For acute myeloid leukemia, an OR=0.11 (95% CI 0.02-0.97) was found following acetaminophen use in the second trimester. For acute lymphocytic leukemia, the exclusive use of dipyrone during preconception showed an OR=1.63 (95% CI 1.06-2.53) and dipyrone intake during lactation showed an OR=2.00 (95% CI 1.18-3.39). These results suggest that acetaminophen use during pregnancy may protect against development of early age leukemia in the offspring, whereas dipyrone use may act as a risk factor for such an outcome.

Pregnancy, maternal exposure to hair dyes and hair straightening cosmetics, and early age leukemia.

OBJECTIVE: To investigate the association between maternal exposure to hair dyes and hair straightening cosmetics (HDSC) during pregnancy and leukemia at an early age (<2yr., EAL). METHODS: A multicenter hospital-based case-control study was carried out in 13 states in Brazil between 1999 and 2007. Mothers of 176 ALL (acute lymphocytic leukemia) and 55 AML (acute myeloid leukemia) cases and 419 controls were enrolled and interviewed. Data on maternal exposure to HDSC occurring 3months before pregnancy, during pregnancy and during breastfeeding were obtained. Data were also gathered on paternal exposure to HDSC before pregnancy. Unconditional logistic regression was performed and odds ratios (OR) on the association between HDSC use and EAL were obtained after adjustment for hormonal intake during pregnancy, maternal age, education, birth weight, and the child skin color. RESULTS: An adjusted OR of 1.78 (95% C.I. 1.13-2.81) was observed between maternal exposure to HDSC in the first trimester of pregnancy and ALL. Regarding AML, an adjusted OR of 2.43 (95% C.I. 1.13-5.22) was found for maternal exposure to HDSC during breastfeeding. No association between maternal exposure to HDSC during pregnancy and ALL or AML was observed in children with MLL (Mixed Lineage Leukemia) gene rearrangement. CONCLUSIONS: Results in this study seem to support the hypothesis that maternal exposure to HDSC during pregnancy may be involved in the etiology of leukemia in children under 2years of age.

Familial history of cancer and leukemia in children younger than 2 years of age in Brazil.

The objective of this study was to determine the contribution of a familial history of cancer (FHC) to the development of leukemia in children below 2 years of age. This is a national hospital-based case-control study of children 0-24 months of age recruited from 15 Brazilian hospitals from several regions providing oncological care and local general hospitals. Participants' FHC antecedents were obtained through face-to-face interviews with the mothers of cases and controls using a standardized questionnaire. Unconditional logistic regression was used to determine crude and adjusted (adj.) odds ratios (OR), and the respective 95% confidence intervals (CI), of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) after adjustment for selected variables. FHC antecedents were obtained from 178 ALL, 51 AML, and 428 controls. FHC in second-degree relatives (grandparents, uncles, cousins) showed an adj. OR=1.66 (95% CI 1.12-2.45) for ALL. Antecedents of two or more relatives with cancer showed a statistically significant two-fold higher risk of either ALL or AML. Paternal, and joint paternal and maternal antecedents of cancer also showed statistically significant higher adj. OR, respectively: 1.80 and 1.89 for ALL, and 2.34 and 3.23 for AML. Hematological malignancies among second-degree relatives showed an adj. OR=3.48 (95% CI 1.72-7.09) for ALL. According to the anatomic site, antecedents of leukemia/lymphoma among case relatives, compared with the control ones, showed an OR=2.98 (95% CI 1.52-5.82) for ALL, whereas stomach cancer antecedents showed an OR=3.55 (95% CI 1.02-12.39) for AML. The observed results support the hypothesis that FHC antecedents are associated with leukemogenesis in children below 2 years of age.