Benign breast disease, family history studied

By Gene Emery

BOSTON (Reuters) – Women diagnosed with benign breast
disease but who do not have a strong family history of breast
cancer have no heightened risk of developing a tumor, according
to a new study.

“If women do not have a strong family history, the risk
does not increase,” said Lynn Hartmann, chief author of the
report, which appears in Thursday’s New England Journal of
Medicine.

“Most of what we’re putting out there, I would put in the
‘good news’ category,” Hartmann, an oncologist at the Mayo
Clinic, added.

Doctors have long known changes in the breast are often a
harbinger of cancer. Hartmann’s study looked at 9,087 women
with benign breast disease for an average of 15 years to
quantify those risks.

Among women with cysts, also known as nonproliferative
disease, researchers found the breast cancer risk was 27
percent higher than expected.

That was the most common type of benign disease found in 67
percent of the women in the study, and 1 million women in the
United States are diagnosed with such disease every year.

For every 100 women with nonproliferative disease, about
six will develop breast cancer, compared with five cases in 100
expected over the 15-year period among women in the general
population.

A cyst occurs when a breast duct becomes enlarged and
filled with fluid, and the tissue around the duct thickens
because it contains too much collagen.

In cases of atypical hyperplasia, where cells of the breast
look too large, too abundant and abnormal under the microscope
– but not abnormal enough to be cancerous — the risk of
breast cancer quadruples.

In that case, 19 out of 100 of those women are likely to
develop a tumor over the next 15 years.

But only 4 percent of women with some type of benign breast
disease fall into that category. Hartmann told Reuters that
earlier estimates set the risk much higher — perhaps eight to
10 times higher among women with a family history of breast
cancer. “We don’t see that,” she said.

Those women, especially younger women, may be candidates
for taking drugs like tamoxifen, which is designed to prevent
breast cancer, or having their breasts checked using MRIs
instead of conventional mammography.

“You need to make sure the surveillance is the best it can
be,” she said.

In intermediate cases, representing about 30 percent of the
women in the study, the cells seem to be growing a little too
rapidly, but they still look normal.

Among those women, the risk of breast cancer was twice what
would normally be expected, or 10 women out of 100 during the
15-year period.

Age plays an important role in the risk. Women diagnosed
with atypical hyperplasia under the age of 45 face twice the
risk of cancer than women found to have hyperplasia at age 56
and over.