Since the link you posted explicitly mentions bowel and breast cancer I'll focus on those.
This study (2007) is about increased bowel cancer risk:
We conducted a
meta-analysis of prospective cohort
studies published between 1990 and
June 2005 on the relationship between
alcohol intake and colon and rectal
cancer.
High alcohol intake was significantly
associated with increased risk of
colon and rectal cancer when comparing the highest with the lowest category of alcohol
intake, equivalent to a 15% increase
of risk of colon or rectal cancer for
an increase of 100 g of alcohol intake
per week.
Here (2007) is a meta-analysis of studies of alcohol and breast cancer:
98 unique studies were
included, involving 75,728 and 60,653
cases in drinker versus non-drinker
and dose-response analyses,
respectively.
... we confirm the alcohol-breast
cancer association. We compared our
results to those of an individual
patient data analysis, with similar
findings. We conclude that the
association between alcohol and breast
cancer may be causal.
Here is a study that looked into "moderate alcohol intake and cancer incidence in women":
A total of 1,280,296 middle-aged women
in the United Kingdom enrolled in the
Million Women Study were routinely
followed for incident cancer.
Low to moderate alcohol consumption in
women increases the risk of certain
cancers.
For every additional drink
regularly consumed per day, the
increase in incidence up to age 75
years per 1000 for women in developed
countries is estimated to be about
- 11 for breast cancer,
- 1 for cancers of the oral cavity and pharynx,
- 1 for cancer of the rectum,
- 0.7 each for cancers of the esophagus, larynx and
liver,
giving a total excess of about
15 cancers per 1000 women up to age
75.
But I also found a study that suggests that alcohol could reduce the risk of kidney cancer:
We performed a pooled analysis of 12
prospective studies that included
530,469 women and 229,575 men with
maximum follow-up times of 7-20 years.
Moderate alcohol consumption was
associated with a lower risk of renal
cell cancer among both women and men
in this pooled analysis.
I also suggest taking a look at the "Is alcohol beneficial in small amounts?" question.