TUESDAY, June 1 (HealthDay News) -- Despite prior research
identifying both genetic risks for breast cancer as well as risks
associated with lifestyle and environmental factors, a new British
study reveals that the two types of risk pools appear to operate
independently of one another.
The finding is based on analysis that looked for any evidence of
an interaction between a dozen genetic mutations -- all associated
with a small increase in breast cancer risk -- and 10 established
environmental risk factors, which are factors linked to behavior or
lifestyle. The results are reported in the June 2 online edition of
"We looked at whether lifestyle factors for breast cancer, such as use of HRT [hormone replacement therapy], alcohol consumption and reproductive history, influence the genetic risks," study author Dr. Ruth Travis, of the cancer epidemiology unit at the University of Oxford in the United Kingdom, said in a news release. "And the answer is that they do not."
Travis and her colleagues focused on 7,610 women who had been
diagnosed with breast cancer, as well as nearly 10,200 women who
did not have the disease. All of the women provided blood samples
for genetic testing, as well as detailed information concerning
DNA analyses looked for 12 common genetic variables, while the
authors sifted through the collected lifestyle information in
search of a specific group of environmental risk factors: age at
first menstruation; number of births; age of mother at first birth;
breast-feeding patterns; menopausal status; age at menopause; use
of hormone replacement therapy; body-mass index; height; and
alcohol consumption history.
Genetic risks and environmental risks did not appear to
interact. In particular, the research team noted that despite
previous indications to the contrary, hormone replacement therapy
did not appear to have any significant impact on genetic risk
For more on breast cancer risk, visit the
American Cancer Society.