Neoplastic hypercortisolism: Cut-off values for late-night salivary cortisol & cortisone.

OBJECTIVES

One of the recommended initial tests for diagnosing neoplastic hypercortisolism is the measurement of late-night salivary cortisol (CortisolLNSa). Published cut-off values for CortisolLNSa and late-night salivary cortisone (CortisoneLNSa) vary widely between studies. This study aims to establish cut-off values for CortisolLNSa and CortisoneLNSa using liquid chromatography-tandem mass spectrometry and to determine which salivary hormone performs better in distinguishing between people with and without neoplastic hypercortisolism.

METHODS

A retrospective study was conducted on subjects screened for endogenous hypercortisolism at Amsterdam UMC between December 2015 and February 2022. 25 subjects with and 430 subjects without neoplastic hypercortisolism were included. The diagnosis neoplastic hypercortisolism was confirmed by histology and postoperative clinical features, not on biochemical tests, and excluded based on a follow-up of at least 12 months without progressive clinical signs of neoplastic hypercortisolism. Salivary samples were collected between 22:00-23:59 h and CortisolLNSa and CortisoneLNSa concentrations were measured using liquid chromatography-tandem mass spectrometry.

RESULTS

The median CortisolLNSa was 7.8 nmol/L for subjects with and 0.8 nmol/L for subjects without neoplastic hypercortisolism (p < 0.001). The median CortisoneLNSa was 35.5 nmol/L and 5.3 nmol/L, respectively (p < 0.001). Optimal diagnostic accuracy was established at 2.25 nmol/L for CortisolLNSa (sensitivity 92 %, specificity 89 %, positive predictive value 32.9 %, negative predictive value 99.5 %) and 15.5 nmol/L for CortisoneLNSa (sensitivity 93.8 %, specificity 94.5 %, positive predictive value 46.9 %, negative predictive value 99.7 %).

CONCLUSIONS

We established cut-off values for CortisolLNSa and CortisoneLNSa for the diagnosis of neoplastic hypercortisolism. CortisoneLNSa provided the highest diagnostic accuracy and we therefore recommend it as the preferred salivary measurement.