Doctors are doing more magnetic resonance images, or MRIs, of the
breast to look for cancer, and as expected are finding more
suspicious areas that require follow-up.
But is having the additional screening tool for breast cancer,
the most common cancer in women except for skin cancer, saving
lives?
"That is the question nobody knows the answer to," said Dr.
Melanie Fidler, a radiation oncologist at the Women's' Imaging
Center at Henrico Doctors' Hospital (Parham). "There are no studies
to date to prove that breast MRI saves lives. Those will be long-
term studies."
When the American Cancer Society last year released new
guidelines for when to use magnetic resonance imaging to screen for
breast cancer, it opened up the diagnostic procedure to many more
women.
Women at increased risk were recommended to get annual breast MRI
in addition to having regular clinical exams and annual mammograms,
which are X-rays of the breast.
"With breast MRI, I think we now have the next step in terms of
trying to understand and deal with this disease," said Dr. Gilda
Cardenosa, director of breast imaging at Virginia Commonwealth
University.
"It's rapidly evolving. What I am doing now is different from
what I was doing six months ago." Technique and equipment are
changing.
Among the groups of women considered at higher risk are those
with a breast cancer gene mutation (BRCA1 or BRCA2), and women who
have a 20 percent to 25 percent lifetime risk of breast cancer based
on various factors.
"More patients that need it are starting to get approval from the
insurance companies," Fidler said.
But it's also creating dilemmas.
More women are undergoing biopsies, an invasive procedure in
which a sample of tissue is taken from a suspicious area or tumor
and examined microscopically to see if the cells are cancerous.
Also, MRIs are picking up additional tumors in some patients
already identified by mammography as having at least one tumor. That
has experts questioning whether lumpectomies done to preserve the
breast are really adequate treatment for some patients.
There is speculation that radiation and chemotherapy after
surgery destroy any undetected tumors left behind. But many also
wonder if treatment failure or breast cancer recurrence is the
result of these undetected tumors and conservative treatments.
Researchers are trying to answer these questions and others as
they wait for clear evidence that MRI will reduce breast cancer
deaths. The specialists who treat breast cancer - oncologists,
surgeons and radiologists - don't necessarily agree.
"We are clearly finding disease with MRI we are not finding with
any other modality," said Cardenosa, speaking to a group of women's
health providers at a meeting in Richmond recently on female
cancers. Cardenosa agrees there are a lot of biopsies being done,
but said it's to be expected as doctors learn the technology's
strengths and limitations. There was a similar learning curve when
mammography became the standard of care, she said.
MRI technology uses powerful magnets and radio waves to look
inside the body, creating three-dimensional pictures that can be
looked at layer by layer, or slice by slice. Enhanced areas show up
when a contrast agent injected before the scan comes in contact with
tissue different from surrounding tissue or abnormal tissue. MRI is
better - but about 10 times more expensive - than traditional X-ray
mammography at spotting suspicious areas. A mammogram costs about
$100 compared to breast MRI's $1,500 cost.
"The concern was MRI is probably a better test, but are we going
to have so many false-positives that the benefits of early detection
of cancer are going to be outweighed by all these negative biopsies
you are doing from false-positive MRIs," said Dr. Steven Harms, a
researcher and radiologist at the University of Arkansas for Medical
Sciences.
Harms, a speaker last fall at a breast cancer month event
sponsored by the Ellen Shaw De Paredes Research Foundation,
presented a number of patient cases in which breast MRI found tumors
missed by mammography and also helped surgeons do tailored
lumpectomies.
When used to find the extent of cancer, breast MRI can change
treatment plans. He described one patient diagnosed with early-
stage breast cancer confined to the milk ducts, or ductal carcinoma
in situ. She had an MRI before a scheduled lumpectomy, which showed
cancer thought to be about 2 centimeters was really about 7
centimeters.
"Normally you can't do a lumpectomy on somebody that has a 7-
centimeter cancer," Harms said. "That's because when you think about
doing a lumpectomy, you are usually thinking about taking out a ball
of tissue. Well a 7-centimeter ball out of the breast is going to be
so large that the cosmetic result is not going to be satisfactory."
Harms said using the MRI images, doctors tailored the lumpectomy
to take out a longer, narrower area based on the margins of the
cancer.
"It's kind of a cigar-shaped incisional biopsy," Harms said. "She
had a very acceptable cosmetic result. That's our goal - streamline
the treatment, do the right treatment the first time, do better-
quality care."
Cardenosa said in some cases what is seen on a mammogram is the
"tip of the iceberg," with MRI sometimes showing more widespread
disease - or what could be disease.
"I am convinced the disease I am seeing in my patients today is
disease that I just never knew about before. So how do you bring the
information together."
Breast MRI is even causing some to rethink early stage ductal
carcinoma in situ, or DCIS. MRI has shown that some types of DCIS
calcifications show the same vascular growth as invasive cancers.
One theory suggests that they are invasive cancers that grow ducts.
Recommendations for breast MRI
The American Cancer Society says in addition to mammography,
annual screening using MRI is recommended for women who:
-- have a BRCA 1 or 2 mutation;
-- have a first-degree relative with a BRCA 1 or 2 mutation and
are untested;
-- have a lifetime risk of breast cancer of 20 percent to 25
percent or more using standard risk assessment models (BRCAPRO,
Claus model, and Tyrer-Cuzick);
-- received radiation treatment to the chest between ages 10 and
30, such as for Hodgkin's disease;
-- carry or have a first-degree relative who carries a genetic
mutation in the TP53 or PTEN genes (Li-Fraumeni syndrome and Cowden
syndrome and Bannayan-Riley-Ruvalcaba syndrome).
-- Contact staff writer Tammie Smith at TLsmith@timesdispatch.com
or (804) 649-6572.
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