Barrow researcher explores innovative cancer treatment
For Barrow Researcher Adrienne C. Scheck, PhD, diets are far more than a health fad: Dr. Scheck is researching the potential of a therapy known as the ketogenic diet to complement traditional treatments for brain cancer such as radiation and chemotherapy.
Since the 1920s, the ketogenic diet has been used to control epilepsy, but its popularity has waxed and waned. It is now used almost exclusively in children whose seizures do not respond to conventional drug therapies. The highly regimented diet calls for nearly 80 percent of a patient’s calorie intake to come from fat and less than 1 percent from carbohydrates, with the remainder coming from protein.
Researchers were spurred to investigate the ketogenic diet as a cancer therapy because cancer cells rely primarily on glucose to fuel their metabolism. The diet causes the body to enter a state called ketosis, where fat-derived chemicals called ketones are burned in response to the absence of carbohydrates. It has been theorized that because tumor cells cannot use ketones for energy, this metabolic change would starve tumor tissue, stunting its growth and improving survival rates for cancer patients.
While not ruling out the metabolic explanation, Dr. Scheck’s research has uncovered other ways that the diet acts on tumors.
Dr. Scheck and her team in the Barrow Neuro-Oncology Research Laboratory observed that live tumor models subjected to the ketogenic diet had fewer reactive oxygen species present in and around the cancerous tissue.
The slides on the right show fewer reactive oxygen species (bright green) in tumors exposed to the products of a ketogenic diet (KD) compared to those on the left, which were exposed to a standard diet (SD).
“Reactive oxygen species are created during normal cellular metabolism and are important in the control of many aspects of cell growth—too many or too few are bad for the cell,” says Dr. Scheck. “The metabolism of tumors is higher than that of normal tissue—a feature that may allow them to adapt to increases in reactive oxygen species and contribute to their resistance against chemotherapy.”
Dr. Scheck hypothesizes that by helping to reduce the number of reactive oxygen species tumor cells are accustomed to, the diet may enhance the effectiveness of chemotherapy.
The results of Dr. Scheck’s latest study also suggest that the diet affects gene expression in tumor cells. “We are seeing that the genetic profile of the tumor cells exposed to ketone bodies is shoved more toward the gene expression of normal cells,” says Dr. Scheck.
How the above mechanisms work together to slow cancer growth is not yet clearly defined, but the results of their combined action are reason to take notice. Dr. Scheck’s team reports that a ketogenic diet, combined with traditional therapies such as radiation and chemotherapy, has the potential to slow the growth of living cancer cells and significantly increase survival time.
Nonetheless, the ketogenic diet has its drawbacks. Dr. Scheck cautions that this treatment is very different from diets that people manage on their own. Rather, she says, it is a therapy that requires total compliance and careful monitoring by a trained dietician.
Dr. Scheck notes that the rigors of the diet can make it unappealing. “With the ketogenic diet, you face the same dilemma that patients sometimes face with traditional chemotherapy and radiation, that is, just how detrimental the therapy is to the patient’s quality of life,” she says.
Still, Dr. Scheck is confident that the continuing efforts of her and her colleagues will one day produce a new therapy to augment current cancer treatments, giving doctors and patients a new weapon in the battle against cancer.