May 5, 2007: It has been known for long
that consumption of alcohol is a risk factor for
breast cancer. However, the exact reason for this
has remained obscure.
A new study using a mouse model has now shed some
light on the why and how of the disease.
Alcohol increased the production of a growth
factor known as vascular endothelial growth factor
(VEGF) in tumour cells. The increased levels of
VEGF hastened the formation of new blood vessels
in a process known as angiogenesis, which allows
tumours to grow and metastasise.
VEGF, incidentally, is needed for the formation of
new blood vessels.
The study has concluded that moderate consumption
of alcohol stimulates the growth and progression
of breast cancer by fuelling the development of
new blood vessels, which is compulsory for the
growth of cancer cells. In short, VEGF can promote
the formation of new blood vessels, and this
suggests that alcohol can induce tumour
The scientists who conducted the study suggest the
difference in the weight of tumour is the result
of heightened growth in blood vessels owing to
This happens because when a rodent, or a human,
drinks alcohol, the cells in their bodies go into
overdrive to get rid of the ‘toxins.’ The
stressed-out cells then send out the hormone VEGF
that stimulates the growth of blood vessels.
The study is the first of its kind to use an
animal model that accurately mimics breast cancer.
In the previous studies, human breast-cancer cells
were injected into ‘nude’ mice, or those mice
lacking an immune system. Without a line of
defence, the mice’s bodies would let the foreign
cells grow and scientists could run experiments on
There have also been many studies, which used
toxic levels of alcohol, leading to results that
were less applicable to humans who consumed lesser
quantities of alcohol.
The researchers conclude that their results,
unlike the results of previous studies, can be
directly translated to humans and have
implications both in preventing and helping treat
Normal people produce cancer cells every day,
according to a researcher. But, at the beginning,
the cancer does not have blood vessels. This makes
it easier for the body’s immune system to fend
them off. However, once the cancerous cells
acquire a blood-vessel lifeline, which the new
study suggests is triggered by alcohol, the tumour
BY OUR PHARMA CORRESPONDENT