Summer 2012 Newsletter - UCSF Helen Diller Family ...

Bay Area Breast Cancer SPORE Newsletter
The 5 th International Workshop on Breast Densitometry
and Mammography-Based Risk Assessment was held
June 9-10, 2011 in San Francisco, with 160 participants
representing more than 50 different institutions from
around the world. Investigators attending presented
research on new methods to measure breast density,
genetics and biology of breast density and use of breast
density in clinical practice to determine at what age to start
screening mammography and how often to be screened.
Breast density research is clinically relevant since it is one
of the strongest risk factors for breast cancer. Breast
density is a radiological term and that describes the
relative amounts of fat, epithelial, and connective tissues
that appear on a mammogram due to differences in X-ray
attenuation. Fat appears radiolucent or dark, while
epithelial and connective tissues are radiographically
dense and appear light or white (Figure 1). When
comparing women that have mostly white on their
mammogram (high breast density) to those that have
mostly dark (low breast density), women with high breast
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5 th International Workshop on Breast Densitometry and Mammography-Based
Risk Assessment
By Karla Kerlikowske, MD, UCSF Breast SPORE Investigator
density are at 4 to 6-fold higher risk of developing breast
cancer. For the purposes of this article, high breast density
is defined as an amount of greater than 50% dense tissue
seen on imaging. Of women undergoing mammography,
32% show high density, which exceeds the prevalence of
most risk factors such as family history of breast cancer.
Key findings presented at the 5 th International workshop
include:
• Volume of breast density measured as either
fibroglandular volume or percent fibroglandular volume is
strongly associated with breast cancer risk and improves
the accuracy of risk assessment over clinical risk factors
alone.
• For women aged 40 to 49 years with high breast density,
and with either a first-degree relative with breast cancer
or history of a prior breast biopsy, the benefits versus
harms for performing mammography every two years is
similar to screening an average-risk woman in her
fifties every two years.
• Women with fatty breasts have a decreased risk of
breast cancer. Women with high breast density have
decreased expression of CD36 that helps
development of fat cells in the breast.
• Women aged 50 to 59 years with low breast density
(fatty breasts) could be screened less often than
every two years.
• High breast density is strongly and positively
associated with breast cancer risk for several tumor
subtypes including estrogen-receptor (ER) positive
breast cancer, triple negative breast cancer and
HER2 positive breast cancer.
• rs10995190 single-nucleotide polymorphism (SNP), a
DNA sequence, is associated with breast cancer risk
and high breast density suggesting that the genetics
of breast cancer and breast density may be linked.
Figure 1: Left panel low
density and right panel high
breast density.
• BreastCare (Breast Cancer Risk Education) study is
evaluating a tablet-based intervention to increase
patient knowledge about her personal breast cancer
risk including factors that increase risk such as
breast density, and increase patient-physician
discussion of risk-reduction practices.
The workshop was chaired by Drs. Karla Kerlikowske,
John Shepherd and Steve Cummings and sponsored
by UCSF, Daniel and Phyllis Da Costa Funds of the
CPMC Foundation with contributions from the
California Breast Cancer Research Program,
American Cancer Society and the Matakina
International Limited. The next workshop will be held in
2013.