Nutritional deterioration in cancer: The role of disease and diet

Aims: Under-nutrition is a major source of morbidity and mortality in cancer patients. This prospective, cross-sectional study aimed to evaluate the relative contributions of cancer staging, duration and diet on patients' nutritional deterioration. Materials and methods: We included 205 consecutive patients (133 men and 72 women) with head and neck, gastro-oesophageal, colon and rectum cancer, age 53 ± 12 (33-86) years, referred for radiotherapy (primary, adjunctive to surgery, combined with chemotherapy or with palliative intent). We registered clinical variables, nutritional status (percentage of weight loss, Patient-Generated Subjective Global Assessment and body mass index), nutritional requirements, usual diet intake (diet history) and current intake (24-h recall). Results: In stage III and IV, we observed a significant decrease of usual and current energy and protein intake (P=0.002), which were not observed in stage I and II. Reduction in nutritional intake was influenced by disease duration (P=0.04), but when the latter was evaluated in a multivariate analysis, current dietary intake was associated only with staging (P=0.004), thus disclosing a distinct pattern of nutritional intake between stages and diagnosis. Using a general linear model, advanced staging showed the most significant association with nutritional depletion (P=0.0001). We also found significant associations for tumour location (P=0.001), disease duration (P=0.002), nutritional intake (P=0.003) and previous surgery or chemotherapy (P=0.02). Percentage weight loss showed a consistently superior performance with regard to clinical variables and ability to detect mild to extreme nutritional changes. Patient-Generated Subjective Global Assessment had a very high sensitivity and specificity, and a strong capacity for detecting patients at nutritional risk compared with body mass index. Conclusions: Nutritional depletion is multifactorial, dependent mainly on the tumour burden of the host. Percentage weight loss is a sensitive and specific tool that can screen and identify malnutrition effectively. Its joint use with Patient-Generated Subjective Global Assessment, which establishes boundaries for nutritional therapy, will optimise the efficacy of nutritional assessment and support in cancer patients.