[Risk factors for pediatric malignant bone tumors].

INTRODUCTION: Cancer is the result of the interaction of two kinds of determinants: genetic (endogenous) and environmental (exogenous). In the last few decades, pediatric oncology as a whole has progressed, including knowledge of malignant osseous tumors (MOT). Although advances have been made in diagnostic and therapeutic aspects, little progress has taken place in our knowledge of the risk factors involved in their etiopathogenesis.
OBJECTIVE: This review has three objectives: a) to provide an update on MOT-related risk factors in the child and adult population; b) to disseminate knowledge of the main MOT-related risk factors among our colleagues in order to promote research into these factors, diagnosis and future prevention, and c) to request help from our colleagues in the Environment and Pediatric Cancer research project.
MATERIAL AND METHODS: We performed a systematic review of the literature published in the last 30 years on risk factors implicated in the etiopathogenesis of MOT, using Medline, Cancerlit, Science Citation Index and Embase. The search profiles used were: pediatric/childhood malignant bone tumors, pediatric/ childhood bone cancer/neoplasm, osteosarcoma/bone sarcoma/Ewing's sarcoma and risk factors/etiology/epidemiology. The most interesting articles were selected and the most relevant references contained therein were retrieved.
RESULTS: MOT represent 6-7 % of all pediatric neoplasms. The most frequent types are osteosarcoma (OS) and Ewing's sarcoma (ES), representing 56 % and 34 % respectively. OS-related risk factors are the following: a) previous osseous disease (Paget's disease); b) familial-genetic factors (hereditary retinoblastoma, Li-Fraumeni syndrome, Rothmund-Thompson syndrome, Bloom syndrome, familial OS, Diamond-Blackfan anemia); c) chemical factors (antineoplastic drugs); d) physical factors (ionizing radiation); e) biologic factors; f) parental occupation, and g) other factors (artificial osseous implants and traumatisms). ES-related risk factors are the following: a) ethnic-cultural (Caucasian race); b) genetic factors; c) parental occupation (herbicide, pesticide and fertilizer exposure); d) maternal obstetric history, and e) other factors (parental smoking and inguinal hernia).
CONCLUSIONS: Most causes of MOT are unknown. Based on different levels of scientific evidence, the main factors implicated in the etiopathogenesis of OS are: Paget's disease, hereditary retinoblastoma, Li-Fraumeni syndrome, antineoplastic drugs, and ionizing radiation. The main factors related to ES are: Caucasian race, parental occupation, parental smoking, and surgery for inguinal hernia. The main obstacles to greater knowledge of MOT-related factors are: a) their multiple origin; b) the low prevalence in the population; c) lack of environmental health training in pediatrics, and d) the low public and private investment in this research field.