Quality of life as a predictor for survival in patients with small intestinal neuroendocrine tumours.

Health-related quality of life (HRQoL) has been shown to predict overall survival (OS) in several different malignancies, but not in patients with small intestinal neuroendocrine tumours (siNET). We evaluated the influence of HRQoL on survival in patients with siNET. We included 85 patients with advanced siNET who completed the validated HRQoL instruments, EORTC QLQ-C30 and GI.NET21. We used Cox proportional hazards to calculate the hazard ratio (HR) of survival according to the QLQ-C30 summary score, adjusting for clinical variables selected with causal inference. Flexible parametric modelling using cubic splines was used to illustrate the time-dependent relationship between HRQoL and OS. The QLQ-C30 summary score was correlated with overall survival (OS) with an adjusted HR of 0.62 (95% CI 0.46-0.83, p < .001) for each 10-point increase in summary score. Compared to a model using only clinical variables, the summary score increased predictive accuracy by eight percentage units and improved model fit. The inclusion of GI.NET21 with the summary score yielded similar results. HRQoL predicts overall survival in patients with siNET, providing additional information to clinical variables. Measuring HRQoL might be useful when following patients with siNET.