Association between markers of malnutrition and surgical outcomes in patients with long bone metastases: a systematic review

Malnutrition affects up to 80% of patients with advanced cancer and is associated with reduced survival. However, its role in patients with long bone metastases, a growing and complex oncologic population, remains understudied. This systematic review aimed to 1) identify commonly used markers of nutritional status, and 2) report the most studied outcomes in this population. A systematic literature search was conducted up to December 2024. Studies reporting on markers of nutritional status and clinical outcomes in patients with long bone metastases were included. The MINORS tool was used for quality assessment. After screening 7,298 studies, a total of eight studies were included, reporting on seven unique cohorts with 4,670 patients. Five surrogate markers of nutritional status were identified: serum albumin (n=5/7; 71%), body mass index (n=3/7; 43%), muscle mass (n=2/7; 29%), body fat (n=1/7; 14%), and weight loss (n=1/7; 14%). No study examined objective nutritional screening tools. Analyses revealed that malnutrition may increase the risk of prolonged hospital stay and shorter survival in patients with long bone metastases. No association was found with revision surgery or postoperative complications. Our review identified four surrogate markers of nutritional status, with BMI, muscle mass, and body fat showing associations with decreased survival and prolonged hospital stay. Hypoalbuminemia was also linked to poor outcomes, however, since albumin mainly reflects inflammation rather than nutrition, we believe it should not be used as a marker of nutritional status. These findings highlight the substantial heterogeneity in nutritional assessment and emphasize the urgent need for standardized, validated tools to accurately identify malnutrition in this population.