Oncology Nutrition: Exploring the Impact of Cancer Diagnosis and Its Treatment on Nutritional Status

Course Description:

Learn how cancer develops and how major treatment modalities influence nutritional status. This course reviews common nutrition-related side effects and highlights the prevalence and consequences of malnutrition and low muscle mass. It also emphasizes the overlap among malnutrition, sarcopenia, and frailty, and the need for early screening and coordinated care. This program was originally presented as a live webinar on 17 September 2025.

Course Objectives:

• Describe the biological mechanisms of cancer development and the primary modalities of cancer treatment.
• Explain how cancer and its treatments impact nutritional status.
• Identify common nutrition-related side effects associated with different cancer treatments.
• Discuss the prevalence and clinical consequences of malnutrition and low muscle mass in patients undergoing cancer therapy.
• Recognize the overlap between malnutrition, sarcopenia, and frailty, and the importance of early screening and intervention in oncology care.

Key Takeaways:

• Cancer and its treatments can disrupt nutritional status by driving systemic inflammation and causing significant metabolic changes in carbohydrate, protein, and lipid pathways. These metabolic disturbances, combined with nutrition impact symptoms that vary by cancer type and treatment modality, make it challenging for patients to consume and absorb the nutrients they need.
• Malnutrition and low muscle mass are highly prevalent and often underreported in oncology patients, occurring across cancer types and stages and even in individuals with stable body weight or a high BMI. 
• Muscle loss, malnutrition, frailty, and sarcopenia often overlap, creating a cycle of declining function and poorer patient outcomes that require early, routine, and comprehensive screening and assessment in clinical practice.
• Early nutrition intervention and interdisciplinary collaboration are essential, as proactive assessment and coordinated care can improve treatment tolerance, reduce complications, and support better clinical outcomes.

Related Questions:

• What nutrition-related side effects commonly impact patients undergoing cancer treatment?
  There are many possible symptoms that can interfere with nutritional intake and absorption in patients undergoing cancer treatment. These may include appetite loss (anorexia), early satiety, nausea, vomiting, diarrhea, constipation, reflux, malabsorption, difficulty swallowing (dysphagia), mouth sores (mucositis), taste changes (dysgeusia), and fatigue. These symptoms vary depending on cancer type, treatment modality, dose, duration, and other medications. Patients often receive multimodal treatments, which can cause symptoms to rapidly compound and negatively impact nutritional status. Ongoing monitoring and early nutrition interventions are crucial for managing these side effects, preventing malnutrition, and reducing further clinical decline.
  
• How common is malnutrition and low muscle mass in patients undergoing cancer therapy, and why is early screening important?
  Malnutrition and low muscle mass are highly prevalent among patients receiving cancer treatment. Approximately 15–50% of all cancer patients present with nutritional deficiencies at the time of diagnosis, and 43% present with overt malnutrition at their first oncology visit, with prevalence rising to as high as 80% during treatment. Low muscle mass is also common, affecting over one-third of patients even when body weight appears stable, and it may coexist with overweight or obesity. There is often overlap between malnutrition, low muscle mass, and frailty, which can worsen treatment tolerance, quality of life, and clinical outcomes. Early screening is important for identifying patients at risk and initiating timely interventions to best support treatment tolerance, slow clinical decline, and improve overall outcomes.
• What barriers make it challenging for clinicians to routinely screen and assess malnutrition and low muscle mass in patients with cancer?
  There are several barriers that make consistent nutrition screening and assessment difficult in oncology settings. Many clinicians report limited access to appropriate screening tools, as well as a lack of skills and limited services to manage malnutrition and sarcopenia. Additional barriers include the absence of standardized screening protocols, unclear referral pathways to nutrition services through the EMR, limited time, and insufficient multidisciplinary involvement. These barriers contribute to delays in recognizing and reporting nutritional issues and emphasize the need for routine, structured screening processes and collaboration across the multidisciplinary care team.