Characterization of Brain & Pituitary Tumor Metabolomics

Omkar B. Ijare, Phd and research associate at the Kenneth R. Peak Brain and Pituitary Tumor Treatment Center is trying to develop methodologies to identify molecular markers of various subtypes of brain and pituitary tumors. Using a variant of conventional MRI it is possible to ‘peak under the hood’ and identify the major metabolites of a tumor mass, prior to treatment.
This can be used to inform physicians, prior to surgery, if they are dealing with a low grade tumor or a very aggressive tumor type. In many tumors this information only becomes available after pathology studies of an excised tumor, when the window for surgical intervention has passed.

Preliminary work involving the characterization of metabolic ‘fingerprints’ in pituitary tumors is already paying dividends. The pituitary tumors typically have high levels of brain metabolite, NAA. However, in tumors of the prolactinoma subtype, it has been shown that the NAA levels are very low. As prolactinoma tumors respond very well to chemotherapy with either cabergoline or bromocriptine, if we screen prolactinoma patients for NAA during the diagnostic workup, we should be able spare these patients from surgery. 

Another example of personalizing medicine comes from selecting a patient’s diet to perturb their tumor growth. Using a metabolic tracer, combined with MRI, can reveal the metabolism used by a particular tumor. Some tumors cannot grow well in the presence of high levels of circulating ketones, produced by ketogenic diet. However, in other tumor subtypes ketones are preferentially used as fuel and enhance tumor cancer cell growth. Knowing which type of tumor a patient has will allow us to issue rational dietary guidance.