Neoadjuvant Vaccination Provides Superior Protection against Tumor Relapse following Surgery Compared with Adjuvant Vaccination

Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada

^* To whom correspondence should be addressed. E-mail: bramsonj{at}mcmaster.ca.

	Abstract

Tumors that recur following surgical resection of melanoma are typically metastatic and associated with poor prognosis. Using the murine B16F10 melanoma and a robust antimelanoma vaccine, we evaluated immunization as a tool to improve tumor-free survival following surgery. We investigated the utility of vaccination in both neoadjuvant and adjuvant settings. Surprisingly, neoadjuvant vaccination was far superior and provided 100% protection against tumor relapse. Neoadjuvant vaccination was associated with enhanced frequencies of tumor-specific T cells within the tumor and the tumor-draining lymph nodes following resection. We also observed increased infiltration of antigen-specific T cells into the area of surgery. This method should be amenable to any vaccine platform and can be readily extended to the clinic. [Cancer Res 2009;69(9):3979–85]

Key Words: tumor, surgery, vaccination, T cells