The Importance of Nutritional Support for Oncology Patients

Cancer patients are amongst the most malnourished patient groups. 

Nutritional support including dietary advice are important tools to manage symptoms and improve nutritional status. 

Oncology dietitian Michele Szafranski explains the importance of nutritional interventions and the role of dietitians in guiding patients through issues they may encounter during and around treatment.

Background

Cancer and cancer treatment can cause difficulties with eating, digestion, absorption, and metabolism, putting cancer patients at risk of malnutrition. In the general oncology population, estimates for the proportion of patients affected by malnutrition vary from ~30–50%,^1,2 but in diagnoses considered the highest risk for malnutrition (head and neck, hepatobiliary, and gastrointestinal cancers) the prevalence may be as high as 80%.³ The recent COVID-19 pandemic and move toward more virtual medical visits has made weight history in the medical record less frequent and inconsistent. Patients may go months without being weighed in an office and may lose a substantial amount of weight in the interim. 

Cancer and Weight Loss

Cancer-related weight loss can be a sign of malnutrition or even cachexia. Patients experiencing weight loss may feel less able to manage adverse events related to their treatment and may feel like they are not able to ‘bounce back’ as well following treatment.⁴

Patients with malnutrition are more likely to require dose reductions and/or treatment interruptions, which can lead to suboptimal cancer treatment and increase the risk of cancer recurrence.⁵

Patients with low muscle mass and high fat mass (sarcopenic obesity) may experience more treatment toxicity than their counterparts with normal muscle mass.⁶ Patients experiencing weight loss tend to have longer hospital stays and are more likely to require readmission. Poor nutritional status can also lead to poor wound healing and increased risk of infection, further delaying recovery from cancer treatment.⁷  

Nutrition-related Adverse Events During Cancer Treatment

All cancer treatments are associated with adverse events that negatively affect patients’ ability to consume sufficient nutrition to meet their needs. Surgical patients may require feeding tubes while they recover, and surgical side effects, such as enzyme deficiencies and short gut syndrome, may impact nutritional intake over the long-term.

Patients undergoing radiation or surgery for some tumors, such as head and neck cancers, may also have difficulty chewing and swallowing, which may become permanent. Radiation can damage salivary glands or lead to scar tissue forming that affects taste and swallowing. Damage from radiation therapy and surgery also results in at least a temporary increase in caloric and protein needs to assist with healing and recovery.

Chemotherapy is associated with a range of adverse events, including nausea, vomiting, diarrhea, constipation, taste changes, and mouth sores that decrease oral nutrition intake. Immunotherapies can also trigger colitis in patients with cancer, which can lead to ongoing diarrhea, weight loss, and dehydration. Additionally, patients and their well-meaning caregivers may make drastic dietary changes in the name of ‘healthy eating’ that eliminate whole food groups and drastically alter the patient’s calorie and protein intake, without understanding that patients with cancer are nutritionally vulnerable. 

The Role of Dietitians

As cancer treatment has largely been moved to the outpatient space, cancer centers are beginning to see the impact dietitians can have on patients’ quality of life. Many governing bodies that accredit cancer centers have suggested that Registered Dietitians (RD) who specialize in cancer care need to be available to patients during all phases of their treatment, with some governing bodies now requiring patient access to dietitians. While access to RD services varies widely internationally, increasing recognition of the role of RDs in managing patients with cancer has led to increases in cancer center staffing levels. Gone are the days when patients needed to search online for answers to all their questions about eating during and after treatment. As with all cancer care, one size does not fit all. A well-trained RD has the time to sit with a patient and discuss the individual’s particular tastes and concerns, allowing them to tailor a program to fit their individual needs. 

Nutritional Interventions

Most nutritional interventions begin with a simple diet recall. Once the RD collects a diet history, they can assess how close the patient is to meeting their estimated daily calorie and protein needs. By assessing weight loss velocity over time, an RD can determine if the treatment modalities and related adverse events are creating a pattern of weight loss and develop a personalized plan to help manage treatment-related adverse events and curb weight loss.

Developing a plan based on foods the patient already enjoys or prefers can help them feel heard and make them feel like an active partner in their treatment plan. Once patients arrest their weight loss, that ‘win’ can build trust with the dietitian and encourage the patient to adhere to dietary advice. 

A recent trend in the oncology nutrition world is nutrition-focused physical examination. 

This involves laying hands on the patient and getting a feel for their muscle mass and fat stores, which can help the dietitian understand any nutritional challenges the patient is facing. Patients with cancer often maintain weight (or lose weight very slowly), but an RD can assess through physical touch whether a patient has lost muscle mass in their legs, arms, and torso, while sparing fat in their abdomen. Tools, such as dynamometers, can also be used to measure hand grip strength and computer programs can analyze computed tomography (CT) scans to determine body fat versus lean muscle to help a dietitian look at the functional status of muscle mass. When an RD discovers declining muscle mass, and explains to the patient the role of adequate intake of not just calories, but also protein, patients are often willing to actively follow the RD’s recommendations. Most patients realize they feel more ‘frail’ or ’weak’ than they would like and are motivated to make even small changes to their diet to improve their quality of life. 

This is the first part of a two-part article. In the second part Michele explains the role of protein in cancer, nutritional challenges and gives us tips on how to increase protein intake from a practical point of view.