Ramón Salazar
Head of Medical Oncology at the Catalan Institute of Oncology (ICO), head of the Colorectal Cancer Research Group, Oncobell programme (IDIBELL) and associate professor of Medicine at the University of Barcelona
As with all studies of predictive models for microbiome signatures, it is very difficult to ascertain whether the validation methodology is reliable – that is, free from noise and bias. This type of analysis tends to suffer from subtle methodological ‘pitfalls’. For external validations, rather than applying a ‘locked’ predictive model with pre-specified cut-off points for each variable and a technically predefined score, the authors adapt the model in various ways (which are complex and difficult to reproduce or understand for non-bioinformaticians) to suit the external validation datasets.
In short, it has no impact on clinical practice and is unlikely to be validated in the future.