The Natural History of Breast Cancer

Abstract

To study the “natural history” of breast cancer implies observing a large number of patients over a long period without any medical intervention. Clearly this has been considered unethical in the modern era yet without knowing the natural history of the untreated disease it becomes impossible to judge the impact of treatment. The modern era can be considered to start in the early 19^th century with the innovations in anaesthesia and antisepsis that within a few decades allowed for the introduction of the Halsted radical mastectomy. Since then we have had to deduce the natural history of disease in retrospect. Along the way a better understanding of the nature and biology of cancer has emerged that contributed to the replacement of radical surgery with ultraconservative techniques together with the elaboration of adjuvant systemic therapies. This chapter charts the paradigm shifts in our conceptual understanding of breast cancer with their therapeutic consequences and concludes that the time is ripe for another paradigm shift and a new era of treatment that relies on chaos theory rather than an obsolete notion of linear dynamics to explain the “unpredictability” of the disease.