who have breast biopsies to diagnose cancer might want to
think twice about the results of the procedures, according to
a new study led by University of Washington researchers.
across the U.S. being tested for their accuracy got the same
results as a panel of experts only about 75 percent of the
time, a variability in opinion that could have a direct effect
on the way women are treated — or not — for potential
1.6 million women in the U.S. have breast biopsies each year,
and about 80 percent come back normal. But the remaining
results may not be as valid as expected, said Dr. Joann G.
Elmore, a UW professor of general medicine and epidemiology
who led the study published Tuesday in the Journal of the
American Medical Association (JAMA).
are perhaps doing some biopsies thinking that it will provide
a definitive guidance, and our study shows that might not be
the case," Elmore said.
the pathologists from across the country were very good at
identifying invasive breast cancer — the most serious
diagnosis — agreeing with the expert panel in about 96
percent of cases.
it came to diagnosing ductal carcinoma in situ, or DCIS, a
noninvasive condition, they were in line with the experts
about 87 percent of the time. And with atypical ductal
hyperplasia, in which abnormal cells are detected, the
pathologists matched the experts 48 percent — less than half
— of the time.
was reassured by the high quality of U.S. physicians in
diagnosing invasive cancer," said Elmore. "I was
surprised by the high level of disagreement in atypia and DCIS."
study provides the first updated analysis of pathologist
disagreement since the 1990s.
and her colleagues, including scientists at Seattle’s Fred
Hutchinson Cancer Research Center, compared the findings of
115 pathologists from eight states — Alaska, Maine,
Minnesota, New Hampshire, New Mexico, Oregon, Vermont and
Washington — with the results of an expert panel between
November 2011 and May 2014.
participating pathologists were randomly assigned to review
one of four test sets of 60 breast biopsy slides, offering a
diagnosis for each case. The slides were weighted to include
more than expected cases of atypia and DCIS, cases from women
aged 40 to 49 and women with dense breast tissue, because age
and density are important risk factors for both benign breast
disease and cancer, the study said.
with the experts, the pathologists under-interpreted, or
missed, about 4 percent of invasive carcinoma, about 13
percent of DCIS cases and about 35 percent of atypia cases,
researchers found. They over-identified atypia in about 17
percent of cases, DCIS in 3 percent of cases and benign breast
disease without atypia in 13 percent of cases.
disagreement was higher among pathologists who interpret fewer
cases each week and those who worked in smaller practices or
inaccurate findings could have direct impact on women’s
care, said Dr. H. Gilbert Welch, a professor of medicine at
Dartmouth University who was not involved in the study. Of the
DCIS cases identified by the pathologists, about 18 percent
were actually not DCIS, which is typically treated in the same
way as invasive carcinoma.
means that, based on the diagnoses, many women would be
advised to undergo lumpectomy, mastectomy and other treatments
that weren’t actually warranted, said Welch, the author of
the new book "Less Medicine, More Health: 7 Assumptions
that Drive Too Much Medical Care."
disagreement is still a problem in the modern century,"
potential for disagreement worries women like Abby Howell, 57,
of Seattle, who underwent two biopsies in 2013 after a
mammogram suggested atypia. Howell was offered the option of
watchful waiting, in which she would have received more
frequent mammograms, but like many women wanting quick action,
she opted for the needle biopsies.
results didn’t ease her mind, however. After procedures,
which were painful and otherwise difficult for her, one test
came back clear, while the other showed atypical cells. A
surgeon suggested that Howell undergo an excisional biopsy,
which would have removed more tissue. She said no—and now
wishes she had skipped the procedures entirely.
I had to do it all over again, I would never get a
biopsy," said Howell, who is cancer-free and has
continued to monitor her progress with mammography. "I
got a biopsy because I was trying to ease my anxiety and it
did the exact opposite."
study suggests that women given the option of watchful waiting
or having biopsies might want to delay, especially for certain
diagnoses, Elmore said. It’s reasonable to seek a second
opinion about whether a biopsy is necessary — or about the
results of completed biopsies — before moving forward.
you’re told that it’s atypia or DCIS, there’s no need to
jump into treatment," Elmore said. "Women should
pause, take a deep breath and realize they’re lucky they
weren’t given the diagnosis of invasive cancer."