FRIDAY, June 24 (HealthDay News) -- Lifestyle changes such as
losing weight, drinking less alcohol and getting more exercise
could lead to a substantial reduction in breast cancer cases across
an entire population, according to a new model that estimates the
impact of these modifiable risk factors.
Although such models are often used to estimate breast cancer
risk, they are usually based on things that women can't change,
such as a family history of breast cancer. Up to now, there have
been few models based on ways women could reduce their risk through
changes in their lifestyle.
U.S. National Cancer Institute researchers created the model
using data from an Italian study that included more than 5,000
women. The model included three modifiable risk factors (alcohol
consumption, physical activity and body mass index) and five risk
factors that are difficult or impossible to modify (family history,
education, job activity, reproductive characteristics, and biopsy
history).
Benchmarks for some lifestyle factors included getting at least
2 hours of exercise a week (for women 30-39) and having a body mass
index (BMI) under 25 (in women 50 and older).
The model predicted that improvements in modifiable risk factors
would result in a 1.6 percent reduction in the average 20-year
absolute risk in a general population of women aged 65; a 3.2
percent reduction among women with a positive family history of
breast cancer; and a 4.1 percent reduction among women with the
most non-modifiable risk factors.
The authors pointed out that the predicted changes in lifestyle
to achieve these goals -- such as former and current drinkers
becoming non-drinkers -- might be overly optimistic.
But, the findings may help in designing programs meant to
encourage women to make lifestyle changes, according to the
researchers. For example, a 1.6 percent absolute risk reduction in
a general population of one million women amounts to 16,000 fewer
cases of cancer.
The study appears online June 24 in the
Journal of the National Cancer Institute, where the author of an accompanying editorial applauded the research.
The findings provide "extremely important information relevant
to counseling women on how much risk reduction they can expect by
changing behaviors, and also highlights the basic public health
concept that small changes in individual risk can translate into a
meaningful reduction in disease in a large population," Dr. Kathy
J. Helzlsouer, of Mercy Medical Center in Baltimore, wrote in a
journal news release.
More information
The U.S. National Cancer Institute has more about
breast cancer risk.