Remove Second Breast to Prevent Cancer?
Study Probes First Breast Cancer and Decision to Get Preventive Mastectomy in Second Breast
Jan. 26, 2009 -- When a woman has a mastectomy to remove breast cancer in
one breast, what should she do about the other breast?
Her first breast cancer may hold some clues, according to a new study,
published in the advance online edition of Cancer.
"Not every woman who has breast cancer will get another breast cancer in
the opposite breast," researcher Kelly Hunt, MD, tells WebMD.
"We tried to distill down some of those factors with our study and
figure out which ones may be the most important ones," says Hunt, a
professor of surgical oncology at the University of Texas M.D. Anderson Cancer
But the findings don't amount to a checklist for getting a preventive
mastectomy; breast cancer experts say that's still a personal decision that
each patient must weigh with her doctors.
Hunt's study included 542 women who had a mastectomy at the M.D. Anderson
Cancer Center to remove a cancerous breast, and also chose to get a
precautionary mastectomy in the unaffected breast, a procedure called
contralateral prophylactic mastectomy.
Immediately after the contralateral prophylactic mastectomy, tests showed
that the vast majority of women -- about 95% -- had no cancer in that breast,
and only 1.5% had an invasive tumor in that breast.
Because women typically get preventive mastectomies to curb their future
risk, Hunt's team also followed another 1,574 women who had mastectomy to
remove a cancerous breast but chose not to have a preventive mastectomy in
their second breast. Over the next four years or so (50 months), only 2.4% of
the women developed breast cancer in their remaining breast. It's not clear how
many of those cancers were invasive tumors.
Hunt and colleagues found three factors that were more common among women
with cancer in the breast that they had removed as a precaution. Those factors
- Having more than one tumor in the breast that was first diagnosed.
- Having invasive lobular cancer in the breast that was first diagnosed.
- Being at high risk for breast cancer, according to the Gail model.
Hunt points out that invasive lobular breast cancer isn't common; it
accounts for about 5% of all breast cancers. And she notes that the Gail model
was designed to gauge future breast cancer risk for women who haven't been
diagnosed with breast cancer; it wasn't intended for use for breast cancer
Hunt says the Gail model may be a "useful tool" for women with
breast cancer, but it will take more studies to confirm that. "We're hoping
to develop a risk calculator that we can put online that would be useful to
clinicians and patients," Hunt says.
"We're learning more and more that all breast cancers are not the same
and they really shouldn't all be treated the same," she says. "We have
general guidelines that really help to make sure women get the appropriate
treatment, but each individual patient has unique factors and features ... that
are important to consider."