Vaccines have now become an accepted, albeit still experimental, method of treating certain cancers. Their use is based on the hypothesis that the growth of cancer in humans depends not only on the intrinsic properties of the tumor, but also on host immune defense mechanisms, which vaccines are intended to stimulate and strengthen. Of the many observations that support this hypothesis, the most compelling is that vaccines can increase resistance to cancer in animals. [1,2] An early experiment that established this principle is illustrated in Figure 1. Most mice immunized with a melanoma vaccine survived challenge with a lethal dose of melanoma cells that invariably killed all nonimmunized mice.  The protection is mediated by immune mechanisms and tumor-specific since melanoma vaccine-immunized mice are not protected against another cancer.
Prevention of murine melanoma by a melanoma vaccine. The figure illustrates the survival of groups of 10 C57BL/6J mice challenged with a lethal dose of murine B16 melanoma cells following 5 weekly immunizations with melanoma vaccine (MAA) in saline (PBS) or in complete Freund's adjuvant (CFA) or with PBS or CFA alone. Note that most vaccine-treated mice, but none of the control mice, are alive at the end of the experiment.
Now that cancer vaccines have been shown to increase resistance to cancer in animals, it is hoped they will do so in humans. The challenge is to design vaccines with this capability. The problems that must be overcome and the strategies available to achieve this goal are discussed below.
© 2001 Medscape
Cite this: Identification of Relevant Cancer Antigens for Vaccine Development - Medscape - Jan 01, 2001.