PURPOSE: To provide guidance on exercise, diet, and weight management during active cancer treatment in adults.METHODS: A systematic review of the literature identified systematic reviews and randomized controlled trials evaluating the impact of aerobic and resistance exercise, specific diets and foods, and intentional weight loss and avoidance of weight gain in adults during cancer treatment, on quality of life, treatment toxicity, and cancer control. PubMed and the Cochrane Library were searched from January 2000 to May 2021. ASCO convened an Expert Panel to review the evidence and formulate recommendations.RESULTS: The evidence base consisted of 52 systematic reviews (42 for exercise, nine for diet, and one for weight management), and an additional 23 randomized controlled trials. The most commonly studied types of cancer were breast, prostate, lung, and colorectal. Exercise during cancer treatment led to improvements in cardiorespiratory fitness, strength, fatigue, and other patient-reported outcomes. Preoperative exercise in patients with lung cancer led to a reduction in postoperative length of hospital stay and complications. Neutropenic diets did not decrease risk of infection during cancer treatment.RECOMMENDATIONS: Oncology providers should recommend regular aerobic and resistance exercise during active treatment with curative intent and may recommend preoperative exercise for patients undergoing surgery for lung cancer. Neutropenic diets are not recommended to prevent infection in patients with cancer during active treatment. Evidence for other dietary and weight loss interventions during cancer treatment was very limited. The guideline discusses special considerations, such as exercise in individuals with advanced cancer, and highlights the critical need for more research in this area, particularly regarding diet and weight loss interventions during cancer treatment. Additional information is available at www.asco.org/supportive-care-guidelines .

Epigenetic modulation of gene activity occurs in response to non-genetic factors such as body weight status, physical activity, dietary factors, and environmental toxins. In addition, each of these factors is thought to affect and be affected by the gut microbiome. A primary mechanism that links these various factors together in mediating control of gene expression is the production of metabolites that serve as critical cofactors and allosteric regulators of epigenetic processes. Here, we review the involvement of the gut microbiota and its interactions with dietary factors, many of which have known cellular bioactivity, focusing on particular epigenetic processes affected and the influence they have on human health and disease, particularly cancer and response to treatment. Advances in DNA sequencing have expanded the capacity for studying the microbiome. Combining this with rapidly improving techniques to measure the metabolome provides opportunities to understand complex relationships that may underlie the development and progression of cancer as well as treatment-related sequelae. Given broad reaching and fundamental biology, both at the cellular and organismal levels, we propose that interactive research programs, which utilize a wide range of mutually informative experimental model systems—each one optimally suited for answering particular questions—provide the best path forward for breaking ground on new knowledge and ultimately understanding the epigenetic significance of the gut microbiome and its response to dietary factors in cancer prevention and therapy.

Obesity and components of energy imbalance, that is, excessive energy intake and suboptimal levels of physical activity, are established risk factors for cancer incidence. Accumulating evidence suggests that these factors also may be important after the diagnosis of cancer and influence the course of disease, as well as overall health, well-being, and survival. Lifestyle and medical interventions that effectively modify these factors could potentially be harnessed as a means of cancer control. However, for such interventions to be maximally effective and sustainable, broad sweeping scientific discoveries ranging from molecular and cellular advances, to developments in delivering interventions on both individual and societal levels are needed. This review summarizes key discussion topics that were addressed in a recent Institute of Medicine Workshop entitled, “The Role of Obesity in Cancer Survival and Recurrence”; discussions included (i) mechanisms associated with obesity and energy balance that influence cancer progression; (ii) complexities of studying and interpreting energy balance in relation to cancer recurrence and survival; (iii) associations between obesity and cancer risk, recurrence, and mortality; (iv) interventions that promote weight loss, increased physical activity, and negative energy balance as a means of cancer control; and (v) future directions. Cancer Epidemiol Biomarkers Prev; 21(8); 1244–59. ©2012 AACR.

Background. A growing body of evidence suggests that diet and exercise behaviors and body weight status influence health-related outcomes after a cancer diagnosis. This review synthesizes the recent progress in lifestyle interventions in light of current guidelines put forth by the American Cancer Society (ACS), the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) and the American College of Sports Medicine (ACSM). Methods. The PubMed database was searched for terms of cancer survivor(s) or neoplasms/survivor, cross-referenced with MeSH terms of lifestyle, health behavior, physical activity, exercise, body weight, obesity, weight loss, diet, nutrition, and intervention studies and limited to randomized controlled trials (RCTs) that had retention rates exceeding 75%. Results. There has been an increase in the number and methodological rigor of the studies in this area, with 21 RCTs identified in the past three years. Results suggest that physical activity interventions are safe for cancer survivors and produce improvements in fitness, strength, physical function, and cancer-related psychosocial variables, whereas dietary interventions improve diet quality, nutrition-related biomarkers and body weight. Preliminary evidence also suggests that diet and exercise may positively influence biomarkers associated with progressive disease and overall survival (e.g., insulin levels, oxidative DNA damage, tumor proliferation rates). Discussion. The evidence base regarding health-related benefits of increased physical activity, an improved diet, and weight control continues to expand. Due to the large (and increasing) number of cancer survivors, more research is needed that tests the impact of lifestyle change on health-related outcomes in this population, especially research that focuses on high-reach, sustainable interventions that recruit diverse, representative samples to help increase the generalizability of findings to the population at large. Concurrent research also needs to address relative benefit in relation to various subpopulations as defined by phenotype, genotype, and/or exposures to treatment, and other lifestyle and environmental factors.

Answer questions and earn CME/CNE The importance of expanding cancer treatment to include the promotion of overall long‐term health is emphasized in the Institute of Medicine report on delivering quality oncology care. Weight management, physical activity, and a healthy diet are key components of tertiary prevention but may be areas in which the oncologist and/or the oncology care team may be less familiar. This article reviews current diet and physical activity guidelines, the evidence supporting those recommendations, and provides an overview of practical interventions that have resulted in favorable improvements in lifestyle behavior change in cancer survivors. It also describes current lifestyle practices among cancer survivors and the role of the oncologist in helping cancer patients and survivors embark upon changes in lifestyle behaviors, and it calls for the development of partnerships between oncology providers, primary care providers, and experts in nutrition, exercise science, and behavior change to help positively orient cancer patients toward longer and healthier lives. CA Cancer J Clin 2015;65: 167–189. © 2015 American Cancer Society.

Overweight and obesity are risk factors for postmenopausal breast cancer, and many women diagnosed with breast cancer, irrespective of menopausal status, gain weight after diagnosis. Weight management plays an important role in rehabilitation and recovery because obesity and/or weight gain may lead to poorer breast cancer prognosis, as well as prevalent comorbid conditions (eg, cardiovascular disease and diabetes), poorer surgical outcomes (eg, increased operating and recovery times, higher infection rates, and poorer healing), lymphedema, fatigue, functional decline, and poorer health and overall quality of life. Health care professionals should encourage weight management at all phases of the cancer care continuum as a means to potentially avoid adverse sequelae and late effects, as well as to improve overall health and possibly survival. Comprehensive approaches that involve dietary and behavior modification, and increased aerobic and strength training exercise have shown promise in either preventing weight gain or promoting weight loss, reducing biomarkers associated with inflammation and comorbidity, and improving lifestyle behaviors, functional status, and quality of life in this high‐risk patient population. Cancer 2012;. © 2012 American Cancer Society.