Anais dos Simpósios de Oncobiologia
Proceedings of the XV Oncobiology Symposium

INTRODUCTION AND OBJECTIVES: Osteosarcoma is the most common aggressive primary bone tumor in children and adolescents. The main symptoms are pain and local or joint swelling. About 20% of patients present pulmonary metastasis at the time of diagnosis, which is confirmed by histological evaluation. Its etiology is not fully understood yet, however, environmental and genetic factors can influence osteosarcoma development. Angiogenesis, induced by vascular endothelial growth factor (VEGF) and its receptor (kinase insertion domain - KDR), is a process involved in tumors development. Both genes (VEGF and KDR) are polymorphic and the association with osteosarcoma is conflicting. Thus, a systematic review of case-control studies that evaluated the association between polymorphisms in these genes and osteosarcoma development was performed. In addition, the frequency of the main VEGF and KDR polymorphisms in a sample of patients from a Brazilian orthopedic referral hospital was described. MATERIAL AND METHODS: The bibliographic search was performed using the Pubmed, Medline, Lilacs and Scielo databases by two researchers independently, using the STROBE method. All papers that investigated polymorphisms in the VEGF and KDR genes and the risk of developing osteosarcoma, published until May 2021 were evaluated. The study from orthopedic referral hospital was approved by the institutional research ethics committee (protocol 17373613.8.00000.5273/2016) and the polymorphisms of VEGF and KDR genes studied in the patient cohort were genotyped by the TaqMan system. RESULTS AND CONCLUSION: Seven articles were included, totaling 1,349 cases and 1,706 controls, all from the Chinese population. These articles had a quality assessment ranging between 77% and 91%. It was observed that most participants from both groups were under 20 years old, male, and had family history of cancer. Six VEGF polymorphisms (-2578 C>A, -1154 G>A, -460T>C, +405 G>C, +936 C>T and +1612 G>A) were analyzed, and no study evaluated KDR polymorphisms. Although the frequencies of VEGF polymorphisms were similar in most studies, the risk of developing osteosarcoma was conflicting among them. The frequency of the variant alleles of the 8 SNPs evaluated in the cases of the reference hospital in orthopedics were: VEGF -2578 A 42.5%, -1154 A 17.5%, -460 C 45%, 405 C 37.5% and 936 T 12.5%, KDR -604 C 22.5%, 1192 T 25% and 1719 A 15.8%. There were differences between the frequencies of the polymorphisms studied in the Brazilian population and those of the Chinese population in the systematic review studies. Studies involving different populations, with appropriate sample size, design and selection of controls are still needed to confirm the role of polymorphisms in VEGF and KDR genes in the development and prognosis of osteosarcoma. These results can contribute to elucidate the etiology of osteosarcoma, which is a relevant public health problem.