Nutrition in Oncology: From Treating Cachexia to Targeting the Tumor

Cancer is a disease closely linked to nutrition. In fact, unhealthy eating habits have been causally related to the onset of some tumors. Also, the clinical journey of cancer patients is characterized by the onset of profound changes in nutritional status, i.e., cachexia, as a consequence of the impairment of host’s metabolism and eating behavior. Finally, anticancer therapies may per se alter host’s nutritional status by inducing toxicity and reduced energy intake, as well as by favoring muscle loss. In daily clinical practice, malnutrition is generally not assessed in cancer patients, and nutrition therapy is considered only in the final stages of patients’ clinical journey. This approach is in contrast with consistent and robust clinical evidence showing that malnutrition is a strong predictor of negative outcome in cancer. Therefore, nutrition therapy should be considered from the very beginning of patients’ journey. Highlighting the relevance of preventing/treating cachexia, recent clinical trials showed that when nutrition therapy is provided early and within a multimodal context which includes psychological support and pain control, then survival is extended and quality of life improved in patients with advanced cancer. Furthermore, recent experimental evidence seem to suggest that use of specific nutrients (i.e., omega-3 fatty acids, glutamine, arginine, branched-chain amino acids, etc.) at key time points during anticancer therapies may have an inhibitory influence on tumor growth. In particular, omega-3 fatty acids have been shown to ameliorate tumor inflammatory microenvironment and enhance response rate to chemotherapy. These preliminary data need confirmation in large clinical trials before their translation into clinical practice. Nevertheless, they may help to shift the consideration of oncologists toward nutrition from a procedure for the last days of life into a key component of anticancer therapies.