Controlled fasting improves the effectiveness of chemotherapy and radiation therapy in mice with aggressive brain tumors, extending their survival, according to research published in September in PLOS One.
The findings of the research team from the University of Southern California (USC) suggest that patients with gliomas may benefit from short-term controlled fasting prior to their radiotherapy treatments (PLOS One, September 11, 2012, Vol. 7:9, e44603).
Malignant glioma accounts for more than 50% of all primary brain tumors, with glioblastoma multiforme being the most common brain tumor in adults. In spite of surgical resection, followed by adjuvant chemotherapy and radiotherapy, the median survival prognosis for patients is 12 to 15 months.
A research team led by Valter Longo, PhD, professor of gerontology and biological sciences at the USC Davis School of Gerontology, undertook a study to investigate whether fasting could improve the efficacy of chemo- and radiotherapies in treating mouse models of aggressive glioblastoma multiforme. This followed earlier research showing that short-term fasting protects healthy cells while leaving cancer cells vulnerable to the toxic effects of chemotherapy.
The researchers discovered that controlled short-term fasting of no more than 48 hours per cycle improved the effectiveness of treatment. More than twice as many mice that underwent a fasting regimen and received radiation therapy survived to the end of the trial period compared to those who had radiation without fasting.
Study data revealed that the beneficial effect of short-term starvation dampened the levels of nutrients and growth factor signaling. This resulted in cellular protection of normal cells, but not cancer cells. Short-term starvation also caused changes in the blood that promoted cancer cell death and further sensitized cancer cells to cytotoxic stimuli such as chemotherapy drugs and radiation.
Longo cautioned that patients should consult with their oncologist before undertaking any fasting. However, "short-term fasting may represent an important possibility for patients who are running out of options," he said.
The USC Norris Cancer Center, the Mayo Clinic, and Leiden University Medical Center in the Netherlands are all conducting clinical trials on fasting and chemotherapy. USC is considering undertaking a clinical trial on gliomas, fasting, and radiotherapy.
