Clinical effectiveness of Enneking appropriate versus Enneking inappropriate procedure in patients with primary osteosarcoma of the spine: a systematic review with meta-analysis.

<bold>Purpose: </bold>Primary osteosarcoma of the spine is a rare osseous tumour. En bloc resection, in contrast to intralesional resection, is the only procedure able to provide Enneking appropriate (EA) margins, which has improved local control and survival of patients with primary osteosarcoma of the spine. The objective of this study is to compare the risk of local recurrence, metastases development and survival in patients with primary osteosarcoma of the spine submitted to Enneking appropriate (EA) and Enneking inappropriate (EI) procedures.<bold>Methods: </bold>A systematic search was performed on EBSCO, PubMed and Web of Science, between 1966 and 2018, to identify studies evaluating patients submitted to resection of primary osteosarcoma of the spine. Two reviewers independently assessed all reports. The outcomes were local recurrence, metastases development and survival at 12, 24 and 60 months.<bold>Results: </bold>Five studies (108 patients) were included for systematic review. These studies support the conclusion that EA procedure has a lower local recurrence rate (RR 0.33, 95% CI 0.17-0.66), a lower metastases development rate (RR 0.39, 95% CI 0.17-0.89) and a higher survival rate at 24 months (RR 1.78, 95% CI 1.24-2.55) and 60 months (RR 1.97, 95% CI 1.14-3.42) of follow-up; however, at 12 months, there is a non-significant difference.<bold>Conclusions: </bold>EA procedure increases the ratio of remission and survival after 24 months of follow-up. Multidisciplinary oncologic groups should weigh the morbidity of an en bloc resection, knowing that in the first year the probability of survival is the same for EA and EI procedures. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]