1. ¹Oncology-Hematology-Bone Marrow Transplant Unit, Department of Oncology, Istituto Scientifico San Raffaele, San Raffaele Hospital, Milan, Italy
2. ²Department of Blood and Marrow Transplantation, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
3. ³NHLBI, National Institutes of Health, Bethesda, MD, USA

Correspondence: Dr M Bregni, Oncology-Hematology-Bone Marrow Transplant Unit, Department of Oncology, Istituto Scientifico San Raffaele, San Raffaele Hospital, Milan I-20132, Italy. E-mail: marco.bregni@hsr.it

Received 6 April 2006; Accepted 1 July 2006; Published online 4 September 2006.

Abstract

In October 2005, the second international meeting on allogeneic transplantation in solid tumors was convened in Stresa (Italy). The aim of this second meeting was to share clinical experiences of allografting in solid tumors, to discuss preclinical data on the mechanisms of graft-versus-tumor (GVT) effect, and to review methods for more efficacious transplant approaches. On the first day, the most recent results in cancer immunotherapy were reviewed; head-to head comparisons of clinical results achieved by standard therapy and by allografting in renal, breast, and ovarian cancer were presented. On the second day, GVT mechanisms and preclinical models were examined; anecdotal reports of a GVT effect in sarcoma, pancreatic cancer, prostate cancer, colorectal cancer and lung cancer were presented; new strategies for optimizing transplant outcome were discussed, including patient selection, tumor debulking, auto–allo approaches, selective T-cell depletion, targeting with monoclonal antibodies, use of killer cell immunoglobulin-like receptor-ligand mismatched natural killer cells. In conclusion, allografting in solid tumors is feasible with limited toxicities and transplant-related mortality; a GVT effect has been documented in many different solid tumors; targeting of the immune response to the tumor by new strategies and identification of the target antigen(s) of the GVT effect are promising areas of research.