Cortisol diurnal variation in blood and saliva of patients with metastatic colorectal cancer: relevance for clinical outcome.

Background: In healthy humans, cortisol displays marked 24-hour rhythms in serum and saliva, with a strong correlation between both fluids; the circadian variation of salivary cortisol is prognostic of longer survival in patients with metastatic breast cancer. In order to confirm these results in a non-hormone-dependent cancer, cortisol concentrations in serum and saliva were compared at different circadian stages, in patients with metastatic colorectal cancer.

Patients And Methods: A first study consisted of round-the-clock sampling for two 24-hour periods, in 18 patients.