Tumor immunology: new perspectives.

This second meeting, organized by the Cancer Immunology Working Group of AACR, concentrated mainly on three areas of importance; these included (a) ways to increase the success rate of vaccination by improving the peptides themselves, improving tumor recognition by using costimulatory molecules or the use of antibodies; (b) how the tumor microenvironment influences T-cell activity and how it can be manipulated to favor survival and action of activated T cells; and (c) a better understanding of myeloid-derived suppressor cells, which represent an ever-growing and diverse group of cells with activities leading to the inhibition of immune responses. It has been accepted that many of these improved therapies may only benefit relatively few patients and recent but rapidly developing research is currently focusing on methods that would allow clinicians to stratify patients receiving immunotherapy into responders and nonresponders, thereby predicting those who are likely to benefit from a specific vaccine therapy; this approach may benefit future clinical trials.