e19099 Background: Surgical resection remains one of the main curative treatment options for most solid-organ malignancies, and oncological surgery caseload has been steadily increasing over the years (1). It has been hypothesized that regional anesthesia may improve cancer related outcome. Both retrospective and prospective studies have been conducted on various cancer types, using different regional anesthesia techniques; and most meta-analyses did not specify the cancer type or regional anesthesia technique as part of their primary outcome (2, 3). In this systematic review, we will review the evidence base of regional anesthesia techniques for each cancer sites. Methods: We systematically reviewed literature from PubMed for studies related to oncological surgery with regional anesthesia, and cancer related outcomes. Main outcomes of interest are recurrence rate or recurrence free survival. The strength of the evidence is reported descriptively. Results: Regional anesthesia techniques most studied in relation to oncological surgery and cancer outcomes are neuraxial (spinal and epidural) anesthesia, and paravertebral block. Neuraxial anesthesia have been shown to improve outcomes in both prostate and ovarian cancer surgeries. On the other hand, current evidence suggest that paravertebral block does not improve breast cancer outcomes, and neuraxial anesthesia does not improve colorectal cancer outcomes. Evidence regarding the use of neuraxial anesthesia in bladder cancer is conflicting. There are also limited evidence suggesting that regional anesthesia may not improve outcomes in lung and upper GI cancers. Conclusions: The protective benefit of regional anesthesia appears to be limited to certain cancer types. More studies are needed in order to determine the effect of regional anesthesia techniques on each cancer types and underlying mechanisms. 1 Vesey SG, McCabe JE, Hounsome L, Fowler S. UK radical prostatectomy outcomes and surgeon case volume: based on an analysis of the British Association of Urological Surgeons Complex Operations Database. BJU Int 2012; 109: 346-54. 2 Sun Y, Li T, Gan TJ. The Effects of Perioperative Regional Anesthesia and Analgesia on Cancer Recurrence and Survival After Oncology Surgery: A Systematic Review and Meta-Analysis. Reg Anesth Pain Med 2015; 40: 589-98. 3 Chen WK, Miao CH. The effect of anesthetic technique on survival in human cancers: a meta-analysis of retrospective and prospective studies. PLoS One 2013; 8: e56540.