Alcohol consumption promotes body weight loss in melanoma-bearing mice

BACKGROUND: Alcohol consumption is an important risk factor for cancer. Little is known about its effects on cancer progression. Previously, we showed that high ethanol consumption inhibited metastasis of B16BL6 melanoma-bearing mice without affecting primary tumor growth. On the other hand, ethanol-consuming tumor-bearing (TE) mice exhibited decreased survival and decreased body weight as compared to water-drinking, tumor-bearing (TW) mice. The focus of this study was to determine how alcohol promotes weight loss in melanoma-bearing mice. METHODS: Female, C57BL/6 mice were given water or 20% w/v ethanol in the drinking water for 3 weeks to 6 months before subcutaneous inoculation of 1 x 10(6) B16BL6 melanoma cells. Mice continued to receive the same fluids. Biochemical parameters were evaluated at various times after tumor inoculation. Body weight, water content, tumor weight and carcass fat content were determined at necropsy. RESULTS: TW mice elicted a modest weight loss. This response was magnified 2-fold by alcohol consumption. The weight loss in TE mice is not caused by dehydration, decreased energy intake, or loss of skeletal muscle mass. It resulted specifically from loss in body fat. Other alterations associated with the fat loss in TE mice were: (1) decreased glucose, (2) elevated fatty acids, (3) elevated beta-hydroxybutyrate, (4) elevated glucagon, and (5) increased leptin levels in plasma. Body temperature decreased about 2.9 degrees C in TE mice. Metabolic rate increased in TW mice. The fat loss due to alcohol consumption in tumor-bearing mice was not due to increased metabolic rate. CONCLUSIONS: The response elicited by alcohol consumption in tumor-bearing mice is complex and associated with alterations in metabolism and hormones. These findings suggest that alcohol abuse could be a risk factor for cancer patients because it invokes a strong depletion of body fat. This could facilitate wasting and shorten survival time.