Impact of a ketogenic diet intervention during radiotherapy on body composition: III. An interim analysis of the KETOCOMP study

BackgroundKetogenic therapy (KT) in the form of ketogenic diets (KDs) and/or supplements that induce nutritional ketosis have gained interest as a complementary treatment for cancer patients. Besides putative anti-tumor effects, preclinical and preliminary clinical data indicate that KT could induce favorable changes in body composition of the tumor bearing host. Here we present first results of our ongoing KETOCOMP study (NCT02516501) study concerning body composition changes among rectal, breast and head & neck cancer (HNC) patients who underwent concurrent KT during standard-of-care radiotherapy (RT).MethodsEligible patients were assigned to one of three groups: (i) a standard diet group; (ii) a ketogenic breakfast group taking 50-250 ml of a medium-chain triglyceride (MCT) drink plus 10 g essential amino acids in the morning of RT days; (iii) a complete KD group supplemented with 10 g essential amino acids on RT days. Body composition was to be measured prior to and weekly during RT using 8-electrode bioimpedance analysis. Longitudinal data were analyzed using mixed effects linear regression.ResultsA total of 17 patients underwent KT during RT thus far (rectal cancer: n=6; HNC: n=6; breast cancer: n=5). All patients consuming a KD (n=14) reached nutritional ketosis and finished the study protocol with only minor problems reported. Compared to control subjects, the ketogenic intervention in rectal and breast cancer patients was significantly associated with a decline in fat mass over time (−0.3 and −0.5 kg/week, respectively), with no significant changes in skeletal muscle mass. In HNC patients, concurrent chemotherapy was the strongest predictor of body weight, fat free and skeletal muscle mass decline during radiotherapy, while KT showed significant opposite associations. Rectal cancer patients who underwent KT during neoadjuvant RT had significantly better tumor response at the time of surgery as assessed by the Dworak regression grade (median 3 versus 2, p=0.04483).ConclusionsWhile sample sizes are still small our results already indicate some significant favorable effects of KT on body composition. These as well as a putative radiosensitizing effect on rectal tumor cells need to be confirmed once the final analysis of our study becomes possible.