For many years, the treatment of cancer has focused primarily on surgery, chemotherapy and radiation. Despite significant advances by the introduction of new chemotherapeutic agents and monoclonal antibodies, almost all these patients eventually become refractory to current treatments.

The failure of current therapies to provide durable remissions in a majority of patients with cancer is thought to be related to the inability of current approaches to effectively eliminate the last tumor cell from the body.  This failure inevitably results in tumor recurrence or metastatic disease that is resistant to therapy.  Although systemic chemotherapy has improved survival of these patients, almost all patients eventually die from their disease.  Therefore, more effective therapies are needed.  Patients at this stage in the disease cycle have no available treatment options with curative potential.

Immunotherapy is an approach that could have a particular role in the treatment of refractory metastatic disease.  For over 200 years, active immunotherapy approaches have been used to successfully prevent numerous infectious diseases, including small pox, rabies, typhoid, cholera, plague, measles, varicella, mumps, poliomyelitis, hepatitis B and the tetanus and diphtheria toxins.  These active immunotherapy concepts are now being applied to develop therapeutic cancer vaccines with the intention of treating existing tumors and/or preventing tumor recurrence.

Cancer vaccines represent an emerging type of biological therapy that is still mostly experimental.  Therapeutic cancer vaccination (e.g., autologous tumor cells, peptide vaccine, dendritic cells, idiotypic antibody, and virus-based vaccine) is a promising approach for treatment of advanced cancers [1].  Unlike current treatment approaches, such as surgery, radiation and chemotherapy, therapeutic cancer vaccination holds the promise of both eliminating the last tumor cells, through immune-mediated mechanisms; as well as the ability, through immunological memory, to continuously protect against tumor recurrence without the need for additional therapy.  In addition, the low toxicity of immunotherapy makes this approach feasible for many elderly patients unable to tolerate toxic active chemotherapy regimens.