Understanding preventive mastectomy: Are genetic risk predictions sound?
New breast cancer discoveries pose agonizing choices for at-risk women
Some women have such pervasive family histories of breast cancer that they hardly stop to ponder whether they’ll develop it. For them, the looming fear is when the diagnosis will come. One way out of the bind is preventive mastectomy. Women who make this choice often tell their stories through the media. Behind each of those cases lies the other story that of women’s health providers and their feelings about the dilemmas posed by discoveries from the genetic research explosion.
Because patients turn to women’s health professionals for answers, this month’s Women’s Health Center Management brings you the latest thinking. It’s not from research scientists. Instead, it’s from your peers who are helping ordinary women apply the breast cancer risk data to their lives.
Regarding the value of prophylactic mastectomy, viewpoints vary widely. On one facet of the issue however, the voices are unanimous: Any woman agonizing over the irreversible choice of breast removal has a right to informed, compassionate guidance. (See guidelines on how to counsel patients, p. 4.)
The furor over risk prediction through family history stems from the genetic research that nailed mutations in two genes, BRCA1 and BRCA2, as causal factors in most familial breast cancer.1 The original studies, centered on a narrow population segment of Ashkenazi Jewish women, found a 76% to 87% chance of developing breast cancer by age 70 in carriers of the genetic alterations.
Risk not uniformly high’
In contrast, a later study from the National Cancer Institute of a general population sample shows that women carrying the altered genes have a 56% chance of getting breast cancer by age 70. Compare that with a 13% chance for carriers of unaltered genes.2 (See resources, p. 3, for access to this and other breast cancer information from the institute.)
"The risk of breast cancer is not uniformly high for all women who carry a BRCA1 or BRCA2 mutation," notes Jeffery P. Struewing, MD, principal investigator at the institute’s Bethesda, MD-based Genetic Epidemiology Branch. Other genes or environmental factors might be involved, he says. (For an example of how much we don’t know, see above graphic.)
In light of the embryonic state of genetic risk predictions, Judith Macon, MA, who is program coordinator at the Betty Ford Comprehensive Breast Center of the Columbia Hospital for Women in Washington, DC, asserts that one of the few instances in which preventive mastectomy is unequivocally the right choice would be in a diagnosis of bilateral breast cancer.
It’s not 100% sure’
Regarding women with strong family histories of breast cancer, "I would not work with any providers who are quick to tell undiagnosed women You should have both your breasts cut off,’" Macon contends. "That would be one option, with the caveat that it’s not 100% sure. Women need to know there’s still some breast tissue left behind."
The residual tissue could become or already be cancerous, she explains. "If a patient asks, What are my options?’ it’s ethical to discuss it with them, but I would question the ethics of a provider who brings it up first."
Among the reasons for considering a prophylactic mastectomy is a familial pattern of breast cancer incidence in the third decade of life.3 However, some women choose preventive mastectomy over lumpectomy to avoid radiation and chemotherapy, says Kelly McAleese, MD, director of the Women’s Imaging Center in Denver.
"Six weeks of radiation and four months of recovery is too much for some women when they’re working," McAleese says.
Cancer is not the only reason for prophylactic breast removal, notes Sandy Hoffman, RNC, MSN, coordinator of Loyola University Medical Center’s Breast Care Center in Maywood, IL. "Sometimes women with benign cysts have to have five, six, or seven biopsies. Some just can’t stand to have another biopsy," Hoffman explains.
When patients mention preventive mastectomy in relation to their family histories, both Hoffman and McAleese urge them to seek genetic counseling. Hoffman finds, "Some women learn that their risk is not as great as they think."
In the same breath, she warns of genetic counseling’s dark side. Once identified as carriers of cancer-prone genes, some women are out of luck because their insurance plans deem any new breast cancers as pre-existing conditions. Recognizing that possibility, McAleese urges women to have genetic tests anonymously.
"We keep confidentiality in our center," she says, but she warns that she can’t speak for other centers should a patient move or switch providers.
Fear is big motivator’
Gathering medical data is merely the first step in choosing preemptive action against breast cancer risk. "The decision should be made by a well-educated patient," says Beth Ann Ditkoff, MD, assistant professor of surgery at New York City-based Columbia University College of Physicians and Surgeons.
The more intently a woman considers such an irreversible course, the more deeply she needs to delve into her emotions. "Fear is a big motivator," McAleese says. "If every time she gets a mammogram, she thinks, This one’s going to be the death call,’ maybe she should have a mastectomy."
On the other hand, cautions Macon, "I would reinforce that this is not something to enter lightly." She urges a second medical opinion. Mastectomy is still major surgery, Macon points out. The residual effects could be chronic lymphedema, which is swelling of the arm caused by lymph node removal.
"If a woman understands the risks, then she could proceed," Macon says, but stresses, "We must impress on women that you cannot eliminate the risk 100%."
References
1. Struewing JP, Hartge P, Wacholder S, et al. The risk of cancer associated with specific mutations of BRCA1 and BRCA2 among Ashkenazi Jews. N Engl J Med 1997; 336:1,401-1,408.
2. National Cancer Institute. Three breast cancer gene alterations in Jewish community carry increased cancer risk, but lower than in previous studies. Update May 14, 1997.
3. Shattuck-Eidens D, Oliphant A, McClure M, et al. BRCA1 sequence analysis in women at high risk for susceptibility mutations: Risk factor analysis and implications for genetic testing. JAMA 1997; 278:1,242-1,250.
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