Skin moles tied to breast cancer risk
June 21 MSN News
The number of moles a woman has may be tied to her risk of developing
breast cancer, according to two new studies.
The studies don't prove that moles cause breast cancer or that women
with a lot of moles will definitely get breast cancer. Instead, they
suggest there may be a small genetic or hormonal link between the two.
"This shouldn't be a concern for women with moles, because we don't
think the relationship is causal," said Marina Kvaskoff, the lead author
of one of the new studies.Kvaskoff is affiliated with INSERM - the
French National Institute of Health and Medical Research - and the
University of Paris 11.Researchers suspected that moles, also known as
nevi, and breast cancer might share links to certain hormones and genes.
That would mean moles could be used to help predict a woman's breast
cancer risk."We always need to discover more causes of cancer and breast
cancer in particular," Kvaskoff said. "If more studies were to find nevi
were associated with breast cancer risk, then nevi could become a risk
marker for breast cancer risk."
In one of the studies, researchers led by Mingfeng Zhang at Brigham
and Women's Hospital in Boston used data collected on 74,523 female
nurses between 1986 and 2010 to measure women's breast cancer risk by
the number of moles on their arms.Women with no moles had about an 8.5
percent chance of developing breast cancer during the study, compared to
an 11.4 percent chance of breast cancer among women with 15 or more
moles on their left arm.
Among women who had already gone through menopause, Zhang and her
colleagues found those with six or more moles had higher levels of
estrogen and testosterone in their blood, compared to women without
moles.
After adjusting their data to account for the differing hormone
levels, the researchers found the link between moles and breast cancer
disappeared.
In the other study that was led by Kvaskoff, researchers found that
French women who reported having "very many moles" were 13 percent more
likely to develop breast cancer between 1990 and 2008 than women who had
no moles. That study included 89,902 total women.
The association disappeared after the researchers adjusted the data
to account for other breast cancer risk factors, including family
history of breast cancer.Kvaskoff said the findings suggest that the
link between the number of moles a woman has and her risk of breast
cancer could be genetic or hormonal. Her team did not have the data to
take hormones into account, however.
The new studies, published in PLOS Medicine, are also limited because
they mostly relied on white women. |