The success of a cancer treatment can be increased by restricting the calorie intake of the patient for a definite period, a new study reveals.
Lead study author Jean-Ehrland Ricci, PhD, of the French Institute for Health and Medical Research in Nice, France, said that it is known that consuming excess calories is associated with increased cancer risk, far less clarity exists in the scientific literature about how calorie restriction and the body's metabolism can potentially affect the body's response to cancer treatment.
Ricci and a team of researchers began by separating the mice into two categories: those who would receive a regular diet and those who would receive a reduced-calorie diet (75 percent of normal intake) for the duration of the experiment.
After the mice consumed either a regular or a reduced-calorie diet for one week, researchers then further divided the mice into four groups according to the treatment they would receive for the following 10 days.
Of the two groups of mice that received a normal diet, one (the control group) did not receive treatment and the other received treatment with an experimental targeted therapy, ABT-737, designed to induce cancer cell death. Of the two groups of mice who received a reduced-calorie diet, one did not receive treatment and the other received ABT-737. On day 17 of the experiment, both treatment and calorie restriction ended, and mice had access to as much food as they desired.
Following this exercise, investigators observed that neither treatment with ABT-737 nor calorie restriction alone increased the survival of mice over that of the other mice; however, the combination of ABT-737 and calorie restriction did. Median survival was 30 days in the control group that received a regular diet and no treatment, 33 days in mice that received a regular diet and treatment with ABT-737, 30 days in mice that received a reduced-calorie diet without treatment, and 41 days in mice that received a reduced-calorie diet and treatment with ABT-737.
Shortly after this experimental period, investigators also observed that the combination of calorie restriction and ABT-737 reduced the number of circulating lymphoma cells in the mice, suggesting that the combination sensitized the lymphoma cells to treatment.
Study results have bee published online in Blood, the Journal of the American Society of Hematology (ASH).