WUNRN
Breast
Biopsies Leave Room for Doubt, Study Finds
By DENISE GRADY - MARCH 17, 2015
Breast biopsies are good at telling
the difference between healthy tissue and cancer, but less reliable for identifying more
subtle abnormalities, a new study finds.
Because of the uncertainty, women
whose results fall into the gray zone between normal and malignant — with diagnoses
like “atypia” or “ductal carcinoma in situ” — should seek
second opinions on their biopsies, researchers say. Misinterpretation can lead
women to have surgery and other treatments they do not need, or to miss out on
treatments they do need.
The new findings, reported Tuesday in JAMA,challenge
the common belief that a biopsy is the gold standard and will
resolve any questions that might arise from an unclear mammogram orultrasound.
In the United States, about 1.6
million women a year have breast biopsies; about 20 percent of the tests
find cancer. Ten percent identify atypia, a finding
that cells inside breast ducts are abnormal but not cancerous. About 60,000
women each year are found to have ductal carcinoma in situ, or D.C.I.S.,
which also refers to abnormal cells that are confined inside the milk ducts and
so are not considered invasive; experts disagree about whether D.C.I.S. is
cancer.
“It is often thought that getting
the biopsy will give definitive answers, but
our study says maybe it won’t,” said Dr. Joann G. Elmore, a professor at the
University of Washington School of Medicine in Seattle and the first author of
the new study on the accuracy of breast biopsies.
Her team asked pathologists to
examine biopsy slides, then compared their diagnoses with those given by a
panel of leading experts who had seen the same slides. There were some
important differences, especially in the gray zone.
An editorial in JAMA called
the findings “disconcerting.” It said the study should be a call to action for
pathologists and breast cancer scientists to improve the accuracy of biopsy
readings, by consulting with one another more often on challenging cases and by
creating clearer definitions for various abnormalities so that diagnoses will
be more consistent and precise. The editorial also recommended second opinions
in ambiguous cases.
A second opinion usually does not
require another biopsy; it means asking one or more additional pathologists to
look at the microscope slides made from the first biopsy. Dr. Elmore said
doctors could help patients find a pathologist for a second opinion.
A surgeon not involved with the
study, Dr. Elisa Port, a co-director of the Dubin Breast Center and the chief
of breast surgery at Mount Sinai Hospital in Manhattan, said the research
underlined how important it is that biopsies be interpreted by highly
experienced pathologists who specialize in breast disease.
“As a surgeon, I only know what to
do based on the guidance of my pathologist,” Dr. Port said. “Those people
behind the scenes are actually the ones who dictate care.”
In Dr. Elmore’s study, the panel of
three expert pathologists examined biopsy slides from 240 women, one slide per
case, and came to a consensus about the diagnosis.
“These were very, very experienced
breast pathologists who have written textbooks in the field,” Dr. Elmore said.
Then the slides were divided into
four sets, and 60 slides were sent to each of 115 pathologists in eight states
who routinely read breast biopsies. The doctors interpreted the slides and
returned them, and the same set was sent to the next pathologist. The study
took seven years to complete.
The goal was to find out how the
practicing pathologists stacked up against the experts. The task was tougher
than actual practice, because in real cases pathologists can consult colleagues
about ambiguous findings and ask for additional slides. They could not do so in
the study.
There was good news and bad news.
When it came to invasive cancer — cancer that has begun growing beyond the
layer of tissue in which it started, into nearby healthy tissue — the outside
pathologists agreed with the experts in 96 percent of the interpretations,
which Dr. Elmore called reassuring. They found the vast majority of the
cancers.
For completely benign findings, the
outside pathologists matched the experts in 87 percent of the readings, but
misdiagnosed 13 percent of healthy ones as abnormal.
The next two categories occupied the
gray zone. One was D.C.I.S. For this condition, the pathologists agreed with
the experts on 84 percent of the cases. But they missed 13 percent of cases
that the experts had found, and diagnosed D.C.I.S. in 3 percent of the readings
where the experts had ruled it out.
The finding is of concern, because
D.C.I.S. sometimes becomes invasive cancer, and it is often treated like an
early-stage cancer, with surgery and radiation. Missing the diagnosis can leave
a woman at increased risk for cancer — but calling something D.C.I.S. when it
is not can result in needless tests and treatments.
The second finding in the gray zone
was atypia, in which abnormal, but not cancerous, cells are found in breast
ducts. Women with atypia have an increased risk of breast cancer, and some
researchers recommend surgery to remove the abnormal tissue, as well as
intensified screening and drugs to lower the risk of breast cancer.
But in the study, the outside
pathologists and the experts agreed on atypia in only 48 percent of the
interpretations. The outside pathologists diagnosed atypia in 17 percent of the
readings where the experts had not, and missed it in 35 percent where the
experts saw it.
“Women with atypia and D.C.I.S. need
to stop and realize it’s not the same thing as invasive cancer, and they have
time to stop and reflect and think about it, and ask for a second opinion,” Dr.
Elmore said.
Abby Howell, 57, who lives in
Seattle, two years ago had some calcifications show up on a mammogram, which are sometimes a sign of
cancer. She was given the option of just mammograms every six months or having
a biopsy. She chose the biopsy, thinking it would be definitive. But instead,
it showed atypia.
Ms. Howell, who has a master’s
degree in public health, looked up the condition and realized it was unclear
whether those odd-looking cells would ever lead to cancer. Surgery was
recommended, but she decided to watch and wait instead. So far, her mammograms
have been normal, but the experience has shaken her peace of mind.
“If I had to do it all over again, I
wouldn’t have jumped for the biopsy,” Ms. Howell said. “I really regret it. In
a way it’s made more anxiety in my life.”