ABSTRACT
This chapter discusses the evolution over time of our understanding of the role of nutrition in cancer treatment, prevention, and survivorship. From the earliest observations that malnutrition and starvation were a cause of death from cancer and often a comorbidity, patients and doctors attempted to cure cancer by treating the malnutrition. Ultimately, it was clear that malnutrition was secondary to cancer and that it was not possible to starve the cancer or save the patient by manipulation of human nutrition. In the 1970s, aggressive enteral and total parenteral nutrition were attempted in advanced cancer demonstrating supportive but not curative effects. The origins of malnutrition in cancer patients secondary to the abnormal metabolism of the tumor were first thought to be solely metabolic with a drain of glucose and protein secondary to the growth of the tumor. The discovery of inflammatory cytokines in the 1980s clarified for the first time how the tumor’s effects on the immune system impaired the normal adaptation to starvation of the patient through systemic effects. In the 1980s and 1990s, nutritional epidemiology combined with basic science insights dominated nutrition and cancer research leading to national and international guidance on foods which could reduce or increase cancer risk. As this epidemiological research led to insights into the foods and nutrients associated with common forms of cancer, the role of nutrition in treatment became a secondary area of research interest maintained by a dedicated group of scientists. In the last few years, the discovery of the microbiome and its potential impact on immune function has increased interest in the role of nutrition in the immune support of the cancer patient and a potential role in cancer immunotherapy. Some tumors blind the immune system through the production of proteins (e.g., PD-1 and PD-L1) so that binding these proteins with antibodies can unleash a systemic immune response capable of eradicating metastatic lesions. Observations of melanoma patients who received broad-spectrum antibiotics demonstrated the importance of the microbiome in immunotherapy. Finally, the successes of precision nutrition leading to robotic surgical removal of precancer (e.g., benign prostate cancer) and small-molecule growth inhibitory drugs (e.g., imitinab) led to long-term remissions and cures of cancer so that there are now 11 million cancer survivors in the US whose long-term outcome is affected by obesity, overweight, hypertension, diabetes, and heart disease. Therefore, nutrition has a developed role in cancer treatment, support of the cancer patient, the prevention of cancer, and in the survival of those whose cancers have been successfully treated.
