Study provides clues to alcohol's cancer connection

For the first time scientists have demonstrated a model that may explain how alcohol stimulates tumor growth. Their
study, published in the January 15, 2005 issue of CANCER (interscience.wiley/cancer-newsroom), says alcohol fuels the production of a growth factor
that stimulates blood vessel development in tumors, and that chronic ethanol increased tumor size and levels of the
angiogenic factor and levels of the angiogenic factor and vascular endothelial growth factor (VEGF) in an experimental model.



For almost a hundred years mounting epidemiological evidence has linked alcohol use to an increased risk of cancers of the
stomach, esophagus, liver, breast, and colon. Researchers have never developed an adequate model to explain how ethanol or a
metabolite of ethanol may cause cancer. Hypotheses abound, and include such diverse theories as acetaldehyde carcinogenicity,
dietary imbalances, and impaired nutrient metabolism and detoxification due to alcohol consumption, activation of
precancerous enzymes, and suppression of the immune system.


Recent data in a cellular model has demonstrated that ethanol increases cellular production of VEGF, an important signaling
protein in blood vessel growth, particularly in tumors. Jian-Wei Gu. M.D. from the University of Mississippi Medical Center
and colleagues further investigated the possible mechanism between ethanol-induced blood vessel growth and VEGF using a chick
embryo model. The investigators exposed chick embryos inoculated with fibrosarcoma cells to saline or physiologically
relevant levels of ethanol for nine days.


The investigators found that compared to the saline control group, the embryos exposed to ethanol experienced increases in
tumor size, tumor blood vessel density, cancer cell infiltration of blood vessels, and VEGF levels. Tumor volume and
intratumoral vascular volume more than doubled. There was also a significant dose-related increase in VEGF mRNA and protein
expression in tumors and cultured cells. Embryos exposed to ethanol had more than eight times the level of cancer cell
invasion of blood vessels compared to the control group.


The authors say their findings "support the hypothesis that the induction of angiogenesis and VEGF expression by ethanol
represent an important mechanism of cancer progression associated with alcoholic beverage consumption."


Article: "Ethanol Stimulates Tumor Progression and Expression of Vascular Endothelial Growth Factor in Chick
Embryos,"Jian-Wei Gu, Amelia Purser Bailey, Amanda Sartin, Ian Makey, Ann L. Brady, CANCER; Published Online: December 13,
2004 (DOI: 10.1002/cncr.20781); Print Issue Date: January 15, 2005.


John Wiley & Sons, Inc