Part II: Vaccines for haematological malignant disorders.

The search for new therapeutic approaches to haematological malignant disease involves exploitation of the antitumour potential of adaptive immunity-the most specific killing system against cancer currently known. Here, we summarise immunological strategies behind active specific immunotherapy, and describe the clinical and immunological results from trials published to date. Available data in humans support the hypothesis that various vaccination regimens can polarise adaptive immunity towards effective control of cancer-cell growth. However, the exploratory nature of clinical studies done thus far does not allow any cancer vaccine to be used as standard treatment for haematological malignant disorders. Because the cause of disease recurrence is the presence of minimal residual disease after conventional treatments, the adjuvant setting might be the most appropriate therapeutic strategy for active specific immunotherapy, when the immunosuppressive effects of bulky disease are virtually absent and when the effector-target ratio is favourable. In the near future, completion of randomised phase III trials as well as clinical implementation of the most recent insights into tumour immunology that aim to overcome immune tolerance towards malignant cells should allow investigators to define the actual role of vaccines in the management of haematological tumours.