(P 034) REGIONAL ANESTHESIA IMPROVES METASTASIS FREE SURVIVAL AFTER SURGICAL RESECTION OF BONE SARCOMAS

Objective: Previous studies have suggested that the increased rate of metastasis during the perioperative period may be due to a stress response provoked by surgery. Despite the basic science research supporting the utility of regional blocks in tumor resection, clinical practice for sarcoma resection remains unchanged. The objective of this study is to provide the first robust retrospective cohort study on the impact of regional versus general anesthesia in sarcoma resection surgery on oncological outcomes.

Methods: This retrospective cohort study reviewed all patients who underwent a surgical resection of a primary non-metastatic bone or soft tissue sarcoma located in an extremity at a single tertiary care referral center from 2007 – 2017. As bone and soft tissue sarcomas are pathologically and clinically distinct from one another, these groups were analyzed separately. (Figure 1) Metastasis-free survival (MFS), recurrence-free survival, and overall survival was calculated for each patient. Kaplan-Meier curves, univariate and multivariate hazard ratios were used to compare outcomes between patients who received any kind of regional anesthesia versus patients who received general anesthesia alone.

Results: The 100 patient cohort with bone sarcoma demonstrated regional anesthesia had a protective effect on oncological survival outcomes. (Figure 2) Patients who received regional anesthesia during their tumor resection surgery had a multivariate HR of 0.47 (p = 0.034) for MFS after adjusting for age of the patient and grade of the tumor. (Table 1) In contrast, the 215 patients in the soft tissue sarcoma cohort demonstrated that regional anesthesia had a neutral effect on oncological survival outcomes with a multivariate HR of 1.11 (p = .640) after adjusting for chemotherapy administration and size of the tumor. (Table 2)

Conclusion: The results from this study provide statistical evidence that, when clinically appropriate, regional anesthesia may provide a protective effect for disease progression in patients undergoing resection of bone sarcoma.