Pesticide exposures in children with non-Hodgkin lymphoma

BACKGROUND: The association between pesticide exposure and non-Hodgkin lymphoma (NHL) in adults has been the subject of numerous case-control and cohort studies. However, to the authors' knowledge, data regarding pesticide exposures in children diagnosed with NHL have been lacking. METHODS: The Children's Cancer Group conducted a study comparing 268 children who developed NHL or leukemia with bulk disease with a group of matched, randomly selected regional population controls. The telephone interviews of both the case and control mothers included selected questions regarding occupational and home exposures to pesticides around the time of the index pregnancy and exposure of the child. RESULTS: A significant association was found between risk of NHL and increased frequency of reported pesticide use in the home (odds ratio [OR] = 7.3 for use most days; trend P = 0.05), professional exterminations within the home (OR = 3.0; P = 0.002), and postnatal exposure (OR = 2.4; P = 0.001). Elevated risks were found for T-cell and B-cell lymphomas; for lymphoblastic, large cell, and Burkitt morphologies; and in both young (age < 6 years) and older children. There was an increased risk of NHL with occupational exposure to pesticides (OR = 1.7) that was not significant overall, but that was significant for Burkitt lymphoma (OR = 9.6; P < 0.05). CONCLUSIONS: The results of the current study provide further evidence linking pesticide exposure to the risk of NHL, but the authors were unable to implicate any specific agent.     

Osteosarcoma as a second malignant neoplasm in children.

Nine patients who had an osteosarcoma that had developed as a second malignant neoplasm in a previously irradiated site were managed at a major center for the treatment of tumors in children. The doses of radiation had averaged 4144 centigray (range, 2300 to 8000 centigray) and chemotherapy had been administered, when appropriate, for the primary malignant lesion (Ewing sarcoma, malignant fibrous histiocytoma, Hodgkin lymphoma, neuroblastoma, neurofibrosarcoma, rhabdomyosarcoma, and Wilms tumor). The interval between the initial treatment and the diagnosis of the secondary sarcoma averaged ten years and one month (range, five years and ten months to twenty-one years and nine months). Three patients were alive, two of them with active disease, at the time of writing. The other six had died within three years (average, fifteen months) after the second diagnosis. The prevalence of secondary osteosarcoma is increasing as the survival of children who have a malignant lesion increases. Plans for tumor therapy should take into account the risk of this complication, which is usually fatal.     

Lysozyme synthesis in osteoclasts.

Osteoclasts may or may not be directly related to monocytes and macrophages, but it is well established that these cell types share a number of features in common. In the present study we sought to extend this comparison by assessing lysozyme synthesis in osteoclasts, an enzyme known to be produced and secreted in large amounts by monocytes and macrophages. Our data show that freshly isolated chicken osteoclasts and osteoclasts in situ contain an abundant amount of lysozyme and correspondingly high steady-state levels of the enzyme's messenger RNA. Marrow macrophages, at various stages of in vitro maturation, also possess lysozyme mRNA but in amounts approximately two to four times lower than osteoclasts. These observations reaffirm the monocyte-macrophage nature of the osteoclast but raise questions about the function of the lysozyme in this cell. At present, the role of the lysozyme in osteoclast activity remains unexplained.