Tumor growth in patients with tuberous sclerosis complex on the ketogenic diet

New evidence is emerging that the availability of nutrients plays a key role in regulating the mammalian target of rapamycin complex-1 (mTORC1) signaling pathway in human cancers. Tuberous sclerosis complex (TSC) is a genetic disorder which results in the growth of hamartomatous lesions in multiple organs due to insufficient suppression of the mTORC1 pathway. A minority of patients with TSC who develop epilepsy which is intractable to standard anticonvulsant medical and/or surgical treatments are treated with the ketogenic diet. To provide insight into the effects of nutrient manipulation on tumor growth in this condition, we describe our experience in a unique group of patients with known tuberous sclerosis complex who are on the ketogenic diet for seizure control. Methods: A retrospective chart review was performed of patients with TSC treated with the ketogenic diet between January 2002 and May 2007 at Massachusetts General Hospital. Results: Five patients with definite TSC underwent serial imaging for tumor growth while on the ketogenic diet or had unchanged imaging prior to the onset of the diet and after termination. Three out of five patients, all children, had progression of a known tumor or tumors or the development of a new tumor while on the ketogenic diet. Conclusion: In this limited case series of five TSC patients, the ketogenic diet did not induce tumor regression or suppress the growth of TSC-related tumors.