Abstract 712: Salmonella typhimurium A1-R inhibits surgically induced breast cancer metastasis

Abstract

Abstract We investigated the efficacy of tumor-targeting Salmonella typhimurium A1-R in the perioperative period to eradicate micrometastatic disease. Fifty female BALB/c mice were inoculated in the mammary fat pad with metastatic murine mammary adenocarcinoma (4T1-RFP (3×105/mouse), and divided into five groups. Control group (n = 10) with no treatment; surgery group (n = 10) in which the tumor was completely resected at day 21 after cell inoculation; Salmonella typhimurium A1-R (A1-R) (n = 10) in which the primary tumor was treated with A1-R alone at day 10 after cell inoculation; postoperative-administration of A1-R (n = 10) in which A1-R was administrated only after the primary tumor was resected; perioperative administration of A1-R (n = 10) in which A1-R was administrated before and after the primary tumor was resected. Metastatic tumor burden was assessed by quantitative fluorescence imaging of metastasis. Efficacy was assessed by metastatic burden and survival. The study showed that excision of the primary tumor was associated with increased systemic metastatic burden, and postoperative metastases exhibited increased proliferation (p < 0.05). A1-R alone treatment inhibited metastasis compared to untreated control and surgery only (p<0.05). Post-operative A1-R treatment significantly inhabited surgically-induced metastases (p0.05). Perioperative administration of A1-R showed the best efficacy compared to all other treatments in inhibiting surgery-induced metastasis (p<0.05) and prolonged survival (p<0.05). Citation Format: Yong Zhang, Nan Zhang, Robert M. Hoffman, Ming Zhao. Salmonella typhimurium A1-R inhibits surgically induced breast cancer metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 712. doi:10.1158/1538-7445.AM2014-712