Clinical score system in the treatment of Cushing’s disease: failure to identify discriminative variables from the German Cushing’s Registry

To develop a multidimensional and integrated clinical scoring instrument, that encompasses, summarizes and weights appropriately the desired clinical benefits of a treatment for Cushing’s disease (CD).

A panel of 42 variables potentially relevant to the clinical course of CD was predefined by endocrinology experts taking into account relevant literature. Variables as well as biochemical disease activity assessed as urinary free cortisol (UFC) levels were evaluated at baseline and at least after 12 months in patients treated between 2012 and 2016 in two Munich-based academic centres of the German Cushing’s Registry. The primary endpoint was the identification of variables whose changes from baseline to follow-up visit(s) could characterize well biochemical cured from not cured patients after 12 months.

Ninety nine patients with at least two consecutive visits were enrolled. Biochemical data were available for 138 visit-pairs among which UFC was not controlled in 48 (34.8%) and controlled in 90 (65.2%) first visits. In 41 (29.7%) consecutive visits (visit-pairs) changes in biochemical activity categories was observed between visits; concretely: in 17 (12.3%) consecutive visits changing from previously controlled to not controlled, and in 24 (17.4%) from uncontrolled to controlled biochemical activity. Multivariate statistical analyses (especially analyses of variance) based on data of the 138 visit-pairs were performed in order to proof possible effects of biochemical activity on clinical benefits. However, in none of the considered 42 variables corresponding to quality of life-dimensions, laboratory, anthropometric, musculo-skeletal or other clinical areas any statistically significant differences between different categories of biochemical activity were observed.

It was not possible to provide clinical key parameters in our population of patients with CD discriminating biochemical cured from non-cured patients and to construct a clinical scoring system reflecting clinical treatment benefits.