Nutritional deficiency is a common medical problem that affects 15–40% of cancer patients. It negatively impacts their quality of life and can compromise treatment completion. Oncological therapies, such as surgery, radiation therapy, and drug therapies are improving survival rates. However, all these treatments can play a role in the development of malnutrition and/or metabolic alterations in cancer patients, induced by the tumor or by its treatment. Nutritional assessment of cancer patients is necessary at the time of diagnosis and throughout treatment, so as to detect nutritional deficiencies. The Patient-Generated Subjective Global Assessment method is the most widely used tool that also evaluates nutritional requirements. In this guideline, we will review the indications of nutritional interventions as well as artificial nutrition in general and according to the type of treatment (radiotherapy, surgery, or systemic therapy), or palliative care. Likewise, pharmacological agents and pharmaconutrients will be reviewed in addition to the role of regular physical activity.

Disease-related malnutrition (DRM) affects approximately a third of hospitalized patients and is associated with an increased risk of morbimortality. However, DRM is often underdiagnosed and undertreated. Our aim is to evaluate the prognostic value of morphofunctional tools and tests for nutritional assessment in clinical practice. A systematic literature review was conducted to identify studies relating to the morphofunctional assessment of nutritional status and mortality or complications. Evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) method. Twelve GRADE recommendations were made and divided into seven topics: food intake and nutrient assimilation, anthropometry, biochemical analysis, hand grip strength, phase angle, muscle imaging, and functional status and quality of life. From these recommendations, 37 statements were developed and scored in a two-survey Delphi method by 183 experts. A consensus was reached on accepting 26/37 statements. Surveys had high internal consistency and high inter-rater reliability. In conclusion, evidence-based recommendations were made on the prognostic value of morphofunctional assessment tools and tests to assess malnutrition, most of which were found to be feasible in routine clinical practice, according to expert opinions.

Introduction: There is a large body of evidence about immunonutrition formulas; however, there are still doubts about their usefulness in routine clinical practice as compared with standard formulas. In the age of personalized medicine, new studies appear every year regarding several types of patients; therefore, an updated point of view on these formulas is necessary. Methods: The Embase database was searched from 2016 to 14 March 2022. Our criteria were articles published in English and Spanish. The evidence quality was evaluated using GRADEpro, and the review was developed according to the PRISMA statement. Results: In this review, a total of 65 unique records were retrieved; however, 36 articles did not meet the inclusion criteria and were thus excluded. In total, 29 articles were included in the final analysis. In the last few years, many meta-analyses have attempted to identify additional existing studies of surgical patients with certain pathologies, mainly oncological patients. Immunonutrition prior to oncological surgery was shown to cause a decrease in inflammatory markers in most of the studies, and the main clinical events that changed were the infectious complications after surgery. The length of stay and mortality data are controversial due to the specific risk factors associated with these events. Conclusions: The use of immunonutrition in patients who have undergone oncological surgery decreases the levels of inflammatory markers and infectious postoperative complications in almost all localizations. However, more studies are needed to assess the use of immunonutrition based on Enhanced Recovery After Surgery (ERAS) protocols.

A prospective, observational, multicenter, and exploratory study was conducted in 469 gastrointestinal cancer patients undergoing elective surgery. The Malnutrition Universal Screening Tool (MUST) and the Global Leadership Initiative on Malnutrition (GLIM) criteria were used to assess nutritional risk. On admission, 17.9% and 21.1% of patients were at moderate (MUST score 1) and severe (MUST score ≥ 2) nutritional risk, respectively. The GLIM criteria used in patients with a MUST score ≥ 2 showed moderate malnutrition in 35.3% of patients and severe in 64.6%. Forty-seven percent of patients with a MUST score ≥ 2 on admission had the same score at discharge, and 20.7% with a MUST score 0 had moderate/severe risk at discharge. Small bowel, esophageal, and gastric cancer and diabetes were predictors of malnutrition on admission. Complications were significantly higher among patients with a MUST score 1 or ≥2 either on admission (p = 0.001) or at discharge (p < 0.0001). In patients who received nutritional therapy (n = 231), 43% continued to have moderate/severe nutritional risk on discharge, and 54% of those with MUST ≥ 2 on admission maintained this score at discharge. In gastrointestinal cancer patients undergoing elective surgery, there is an urgent need for improving nutritional risk screening before and after surgery, as well as improving nutritional therapy during hospitalization.

A survey study based on a 21-item questionnaire was conducted to assess knowledge and practices of digestive surgeons focused on nutritional support in gastrointestinal cancer patients. At least 5 staff digestive surgeons from 25 tertiary care hospitals throughout Spain were invited to participate and 116 accepted. Malnutrition was correctly defined by 81.9% of participants. In patients undergoing major abdominal surgery, 55.2% considered that preoperative nutritional support is indicated in all patients with malnutrition for a period of 7–14 days. For the diagnosis of malnutrition, only 18.1% of participants selected unintentional weight loss together with a fasting or semi-fasting period of more than one week. Regarding the advantages of enteral infusion, 93.7% of participants considered preservation of the integrity of the intestinal mucosa and barrier function, and in relation to peripheral parenteral nutrition, 86.2% selected the definition of nutrient infusion through a peripheral vein and 81.9% its indication for less than 7 days. Digestive surgeons had a limited knowledge of basic aspects of clinical nutrition in cancer patients, but there was some variability regarding clinical practice in individual cases. These findings indicate the need to develop standardized clinical protocols as well as a national consensus on nutrition support in cancer patients.