Insights of nutrition management for oncology patients

Research studies show that 57% of tumor patients in China suffer from moderate to severe malnutrition, which is especially prominent in gastrointestinal tumors, where 70%-90% of gastrointestinal tumor patients suffer from malnutrition. "If nutrition is not addressed, it will lead to a series of adverse reactions and leave patients in a very poor state to receive treatment." Early weight loss and muscle loss in tumor patients can affect patients' clinical outcomes, said Cong Minghua, deputy director of the Department of Integrative Medicine at the Cancer Hospital of the Chinese Academy of Medical Sciences.

　　A study completed in Canada and Europe on the relationship between body mass index (BMI) and weight loss index and survival in cancer patients established diagnostic criteria for cancer-related weight loss. The results of the study showed that higher rates of BMI reduction and weight loss increased the risk of death.

　　Li Rongrong, deputy director of the Department of Clinical Nutrition at Peking Union Medical College Hospital, said that nutritional risk and malnutrition can lead to reduced treatment outcomes and quality of life. Experimental data showed a 30 percent increase in chemotherapy toxicities among severely malnourished patients with metastatic colorectal cancer. Data from another trial showed that patients with chemotherapy for gastrointestinal and head and neck cancers who did not receive nutritional interventions had significantly lower physiological function scores and significantly worse weight and nutritional status compared to patients who received nutritional interventions.

　　Clinical nutritional support has important implications for oncology patients. "Nutritional therapy is so important that it is called 'first-line therapy' and should be started at the same time as conventional antitumor therapies." Cong Minghua said, "As soon as a tumor patient is clearly diagnosed, nutritional risk screening and assessment of malnutrition should be performed. The most widely used nutritional risk screening tool for malignant tumors at this stage is NRS-2002, which should be completed within 24 hours after the patient is admitted to the hospital." Li Rongrong likewise recommends using the NRS-2002 to screen all patients recovering from malignant tumors for nutritional risk to determine whether patients are at nutritional risk. For those at nutritional risk, malnutrition should be diagnosed using the Consensus on Criteria for the Evaluation (Diagnosis) of Malnutrition (GLIM).

　　Cong Minghua introduced that the European Society for Clinical Nutrition and Metabolism (ESPEN) published the Practice Guidelines for the Nutritional Therapy of Oncology Patients 2021, which suggests that regular assessment of nutritional intake, weight change and BMI, starting from oncology diagnosis and repeatedly used according to the stability of the clinical situation. For patients with abnormal screening, objective and quantitative nutritional intake is recommended to assess the degree of symptoms, muscle mass, physical performance and systemic inflammation that affect nutrition. For nutritional therapy, enteral nutrition (EN) is recommended if nutritional interventions are performed but oral nutrition remains inadequate, and parenteral nutrition (PN) is recommended if EN is inadequate or not feasible. For patients with a severe long-term decline in oral intake, nutritional intake (oral supplementation, enteral or parenteral nutrition) is recommended to be increased slowly over several days with additional measures to prevent refeeding syndrome. For patients with chronic inadequate dietary intake and/or persistent malabsorption, home EN or PN is recommended for appropriate patients.

　　Loss of appetite is also a cause of malnutrition in oncology patients. Li Zengning, chief physician of nutrition department, vice president of the First Hospital of Hebei Medical University, introduced that the loss of appetite in tumor patients can be caused by various factors, which can be divided into primary and secondary anorexia. The cause of primary anorexia is not clear. According to the experimental results, it is believed that the symptoms of anorexia caused by tumor are caused by the alteration of central and peripheral nerve signals that control appetite. This hypothesis involves qualitative and quantitative changes in interleukin-1, tumor necrosis factor-α, ciliary neurotrophic factor, and interleukin-6 in the hypothalamus and gastric region, and may also be the result of an imbalance between peripheral appetite-promoting neuropeptide Y and appetite-reducing melanogenic signals. Metabolites such as lactic acid and ketone bodies produced by tumor cells may also cause nausea and decreased appetite in patients. Common causes of secondary anorexia include depression, constipation and pain. In addition, anti-tumor treatment and narcotic analgesics can also cause loss of appetite or even complete loss of appetite.

　　"Inadequate nutritional intake due to loss of appetite can cause a decrease in whole blood cells, making it difficult for patients to undergo effective treatment. Also weight loss, reduced adipose tissue and skeletal muscle, and decreased quality of life are detrimental to therapeutic measures." Li Zengning said, "An accurate assessment of appetite loss may help raise awareness of cancerous anorexia and thus provide assistance for treatment."