Adjuvant chemotherapy

In this brief presentation, an attempt was made to illustrate why it is not possible to carry over chemotherapeutic trial results from one animal cancer to another or one human cancer to another without corrections for differences in (a) staging, (b) dose response, and (c) tumor regrowth rates. Interrelation of quantitative information on these same three variables has provided useful guidance in the planning and interpretation of experimental therapeutic trials. For example, such integration analyses show that selection and overgrowth of specifically and permanently drug-resistant tumor cells is a major cause of chemotherapeutic failure in cancers that initia-ly respond. Surgery followed by optimum chemotherapy improves the "cure rate" of all metastatic solid animal cancers that have been studied to date. However, surgery followed by chemotherapy fails in those animals in which the residual tumor cell burden (after surgery) is too large for the chemotherapy now available.