Biological Efficacy of a Dendritic Cell-Based Vaccine in a Patient with Metastatic Colorectal Cancer

Abstract

Colorectal cancer is a serious health problem affecting de novo more than one million people every year in the developed world. Despite recent advances in the development of novel therapeutic agents, metastatic colorectal cancer remains mostly incurable and its survival rates ominous even when patients respond to the most advanced treatments. Here, we describe a case in which a patient with metastatic colorectal cancer and high risk of relapse remains disease-free while being treated solely with twelve doses of autologous dendritic cells vaccines pulsed with autologous tumor lysate. A sustained, specific immune response elicited by vaccination has also been documented. Prior to receiving this experimental treatment, the patient had undergone both tumor resections and chemotherapy treatments six times, invariably relapsing/progressing within a year from each resection. We believe that the use of autologous vaccines consisting in dendritic cells pulsed with tumor lysate should be further investigate in human clinical trials, particularly in patients with minimal tumor burden and high risk of relapse. We also believe that this type of immunotherapy is more likely to be successful when used as an early rather than merely compassionate treatment option, given the fact that the more toxicity the immune system has received from previous approaches, the less it will be able to respond to tumor vaccination.