Immunomodulation by anticancer chemotherapy: More is not always better (review)

Chemotherapeutics are the mainstay of the majority of antitumor treatment s trategies. These agents are usually administered at or near maximum tolerat ed doses resulting in frequent dramatic toxicities that compromise the qual ity of life and the immune response towards microbial pathogens. A number o f observations suggest that low-dose treatment with chemotherapeutics is so metimes equal or even superior to high-dose chemotherapy. The efficacy of l ow-dose chemotherapy can be at least partly explained by the regulation of the antitumor immune response. The immunomodulatory effects of some chemoth erapeutics might be further potentiated by combinations with selected biolo gical response modifiers such as recombinant cytokines (IL-2, TNF, IL-12). The effectiveness of such treatment combinations have already proved effect ive in preclinical animal models. However, the efficacy in humans is still to be demonstrated in rationally designed clinical trials.