The association between weight stability and parenteral nutrition characteristics and survival in patients with colorectal cancer

Objective: Knowledge about the impact of metabolic disturbances and parenteral nutrition (PN) characteristics on the survival of cancer patients receiving PN is limited. We aimed to assess the association between clinical and PN characteristics and survival in colorectal-cancer patients receiving PN support. Methods: Our study included 572 consecutive colorectal-cancer patients who had received PN support between 2008 and 2013. Patient characteristics, body mass index, weight, medical/surgical history, indication for PN, PN data and survival were recorded. Associations between clinical and PN characteristics and survival were analysed with important confounding factors. Results: The final cohort included 437 evaluable patients, with a mean age of 57 years. Eighty-one percent of the study population had advanced stage of colorectal cancer. Unstable weight (weight change >2.5%) prior to PN initiation [hazard ratio (HR) = 1.41, P = 0.023] was adversely associated with survival after adjusting for multiple factors including cancer stage. Bowel obstruction (HR = 1.75, P = 0.017) as a PN indication was associated with worse survival when compared with without bowel obstruction. Higher PN amino acid by ideal body weight (g·kg^-1) (HR = 0.59, P = 0.029) was associated with longer survival, whereas a higher percentage of non-PN intravenous calories (HR = 1.04, P = 0.011) was associated with shorter survival independently of confounding factors. Conclusions: Body mass index and weight stability can be useful nutritional indices for survival prediction in cancer patients receiving PN. PN planning should take into account of non-PN calories to achieve optimal energy support and balance. Future research is needed to define optimal PN amino-acid requirement and energy balance.