Serum cholesterol in cerebral malignancies

Reduced blood cholesterol levels were reported in patients with a variety of malignant peripheral tumors. This fact is likely related to increased cholesterol demand by proliferating tumor cells. The question arises whether this 'tumor-associated hypocholesterolemia' occurs also in patients with brain tumors, and - if it does not - whether its absence can be related to the location of the tumors. We have compared fasting serum total cholesterol levels among three groups of patients: 52 patients with gliomas, 56 patients with symptomatic metastatic brain tumors, and 50 patients harboring malignant tumors of peripheral location but showing no clinical signs of brain metastases. Patients in the last group, despite being - on an average - more age-advanced, had lower total serum cholesterol levels than either the patients with gliomas, or the patients with brain metastases. No difference in the cholesterol levels was found between the two latter groups, and a majority of these patients had borderline or elevated cholesterol levels. This apparent absence of 'tumor-associated hypocholesterolemia' in brain tumor patients may be related to either brain tumors' ability to synthesize cholesterol de novo and their reduced dependence on peripheral cholesterol supply, the existence of brain tumor-blood barrier, effect of medications used to counteract brain edema and seizures, or a combination of these factors.