For the past 20 to 30 years, enormous resources have been directed toward the development of effective cancer immunotherapies. The interest in immunotherapeutic approaches comes from the potential specificity imparted by the recognition of tumor-specific antigens combined with the powerful cytolytic properties of cellular and humoral immune effector arms. Earlier attempts to induce and/or expand tumor antigen-specific immune responses in patients involved the systemic administration of cytokines such as interleukin-2 (Proleukin), or immunization with vaccines prepared from whole tumor cells or tumor cell lysates admixed with powerful immunologic adjuvants (stimulators). Unfortunately, only limited efficacy was achieved.
Over the past 15 years, several developments stimulated further interest and growth in the introduction of cancer vaccines to the clinic. They include the rapid progress in understanding the basic features of antigen presentation and immune recognition, thus providing a means for more effective immunization; progress in molecular biology that permitted the identification of numerous potential tumor-specific or tumor-associated antigens; the increased availability of recombinant cytokines, proteins, peptides, and other components necessary to generate a vaccine product; and the relative ease with which foreign genes such as cytokines or tumor antigens could be expressed in viruses and cells.
Despite substantial efforts in the field and progress in basic understanding, critical aspects of the biology and immunology related to optimal induction of antitumor immune responses, and even the basic parameters of an effective antitumor immune response, remain unknown. No clear best approach to inducing antitumor immune responses has emerged. For these reasons, many different cancer vaccines involving many different potential antigens and antigen presentation approaches are currently in clinical development.
The editors of Cancer Vaccines and Immunotherapy have assembled a collection of concise, well-written chapters by several leading figures in the field that highlight many of the major areas of research and the important development issues for cancer vaccines. The initial chapter provides a useful overview of the basic features of antigen presentation, immune recognition of antigen, immune effector arms, the interaction of the host immune system with the tumor during tumor growth, types of tumor antigens, the rationale for the selection of certain tumor antigens and antigen-presentation approaches, and the mechanisms of tumor escape. The chapters that follow address specific immunization approaches (eg, poxviruses, anti-idiotypes, and dendritic cells), vaccine approaches for specific diseases (B-cell tumors, colon cancer, cervical cancer, Epstein-Barr virus-related cancers), and tumor antigen discovery (SEREX [screening of cDNA expression libraries derived from human tumors with autologous antibody] and CTL [cytotoxic T lymphocyte] epitopes).
The chapters generally contain a generous number of helpful illustrations and tables, and are organized to include an introductory section (with basic information on the relevant disease or the basic biology supporting the approach) and conclusions (which encompass future directions). In the final two chapters, the editors provide a useful overview of the major issues introduced and some discussion to relate these issues to current findings and prospective possibilities.
Because the chapters are concise yet cover a broad range of diverse topics, the book will be most useful to oncologists and immunologists who have limited familiarity with cancer vaccines and would like greater knowledge of current issues and developments in the field. The book may also be useful for those seeking more in-depth knowledge of a selected topic, such as poxvirus vectors or vaccine approaches in cervical cancer.
However, because of its organization and selected coverage of topics, the book is not comprehensive and should not be considered a sole source of information on cancer vaccines. For example, the coverage of melanoma vaccineswhich represents a significant portion of the work in the fieldis somewhat limited. Most of the book is devoted to defined-antigen vaccines, with less attention paid to whole tumor cell vaccines, tumor cell lysates, or tumor cell components such as heat-shock proteins, and gene-modified tumor cells. Paradoxically, one chapter is devoted to intravesical bacillus Calmette-Guérin (BCG) instillation for bladder cancer, which is arguably not a cancer vaccine but more of a nonspecific immunotherapy.