Karnofsky Memorial Lecture. Breaking the cure barrier.

Breaking the cure barrier is a biologic and a conceptual problem that has already been accomplished for several tumors. It is helpful to consider neoplasms in mathematical terms as many-celled tumors (polycytomas: kilocytomas, megacytomas, gigacytomas, and teracytomas). A new chemotherapeutic taxonomy recognizes curable, subcurable, and precurable cancers each with definable characteristics. A simplified technique of recognizing early cures is described by calculating the probability that an interruption in an exponential failure slope occurred by chance. Examples of cures of acute myelocytic leukemia, of superior chemotherapy for Hodgkin's disease in young adults, and of superior adjuvant chemotherapy for breast cancer are given. The interaction of surgery with chemotherapy is illustrated in pure form in acute myelocytic leukemia and in ovarian cancer. Curative chemotherapy is closer at hand than is generally believed. Nomograms for cure prediction are presented as inducements to contemplate curative approaches to cancer therapy.