Study Probes First Breast Cancer and Decision to Get Preventive Mastectomy in Second Breast
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 Center.
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.
Mastectomy Study
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.
Key Factors
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 are:
- 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 patients.
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."
Breast Cancer Experts Weigh In
Julie Gralow, MD, director of medical oncology at the Seattle Cancer Care Alliance and an associate professor of oncology at the University of Washington, tells WebMD that the risk factors noted in Hunt's study "make sense," but the study "doesn't convince me that we should be recommending" preventive mastectomy based on those factors.
"Nobody would recommend a prophylactic mastectomy in a group that over the next four years only had a 2.4% chance of getting it on the other side," says Gralow, referring to the comparison group in Hunt's study.
Women who have had breast cancer are at "high risk" for another breast cancer, "but 'high' is a relative term," notes Victor Vogel, MD, the American Cancer Society's national vice president for research.
"Whether the Gail model is the appropriate way to estimate that risk is highly debatable," Vogel says. "What you'd want is a study in which patients with a first breast cancer had a Gail model score, and then in five years, you look to see whether the Gail model accurately predicted the number of second breast cancers. And I am not aware that any such study has ever been done."
Gralow and Vogel also point out that when breast cancer is diagnosed, many doctors now perform MRI scans of both breasts. Those scans help show the extent of breast cancer in the affected breast and check the other breast for cancer.
Hunt's study started before that practice became common, so not all of the patients got MRI scans before opting for preventive mastectomy. Genetic testing also wasn't a routine procedure for the patients in Hunt's study, and isn't recommended for most breast cancer patients.
No Rush to Decide
Hunt, Gralow, and Vogel encourage women to take their time in deciding whether or not to get a contralateral prophylactic mastectomy and to focus on treating the breast cancer that they already know they have.
"A lot of women will come to my office and immediately say, 'Why don't you just take both breasts off?' and I try to explain to them that depending on their risk, not everyone needs that dramatic measure," Hunt says. "I always try to get patients to give much more time and consideration to it."
"There shouldn't be this sense that we have to do this [preventive mastectomy] right now," Vogel says. "This is not urgent, it's not life-threatening immediately ... it can be done after the primary therapy, when you get a little emotional distance from it and you can make these decisions with a calm heart."
Gralow notes that preventive mastectomy hasn't been shown to improve breast cancer survival, though it does cut the odds of getting breast cancer again. That's because if a recurrence happens, chances are it would be found and treated.
No Rush to Decide continued...
Still, "it's perfectly understandable that maybe women wouldn't want to go through that a second time," Gralow says. "For some women, even a couple percent chance of getting another breast cancer is enough to say, 'I just don't want to deal with it.'"
Gralow says she would support a woman who made that choice, as long as the patient understood the risks and benefits. Her advice: "If you're not sure, you shouldn't do it, because it's permanent."
source: webmd.com
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