Women with hereditary breast cancer as a result of a BRCA gene mutation and who undergo a double mastectomy are less likely to die from the disease than women who undergo the procedure on only the affected breast, says a new study published in the journal BMJ.
BRCA genes — BRCA1 and BRCA2 — are genes expressed in the cells of breast and other tissue. The function of the genes is to produce tumor suppressor proteins that help repair damaged DNA or destroy cells if DNA cannot be repaired Women with mutations to the BRCA genes do not produce the tumor suppressor proteins, making cells more susceptible to genetic alterations that can lead to the development of cancer.
According to the National Cancer Institute, BRCA gene mutations account for approximately 20 to 25 percent of hereditary breast cancers and five to 10 percent of all breast cancers. Approximately 55 to 65 percent of women with a hereditary BRCA1 gene mutation and 45 percent with a hereditary BRAC2 gene mutation will develop breast cancer by the age of 70.
Women who are diagnosed with hereditary BRCA breast cancer have a significantly increased risk of second primary breast cancer. Of all women in North America diagnosed with breast cancer associated with a BRCA gene mutation, half choose to undergo a double mastectomy. However, until the present study, no evidence existed to support that a double mastectomy reduced the risk of death among these women.
For the present study, researchers led by Prof. Steven Narod of the Women’s College Research Institute in Toronto, Canada looked at 390 women with a family history of breast cancer who were carriers of BRCA1 and BRCA2 gene mutations. All the women were initially treated with a single or double mastectomy. Of the total participants, 181 underwent a double mastectomy.
The researcher then followed the women for 20 years after the initial breast cancer diagnosis.
Of the 79 women who died during the study, 18 underwent a double mastectomy and 61 a single mastectomy group. A double was associated with a 48 percent reduction in death from breast cancer.
In other words, women diagnosed with hereditary breast cancer as a result of a BRCA gene mutation have an increased risk of death associated with the disease after undergoing a double mastectomy compared to women who chose to remove only the affected breast.
Comments Prof. Narod on the findings, “We now recommend that all women with a BRCA1 or BRCA2 mutation and early stage breast cancer be treated with bilateral mastectomy. Also, genetic testing should be offered to more breast cancer patients at the time of diagnosis.”
The researchers do note that additional research is necessary to confirm the findings of the present study. Adds Prof. Narod, “[We will also] explore the benefit of hormonal therapies in women with BRCA1 mutations and estrogen receptor-negative breast cancers.”
Another recent study on breast cancer discovered that young women who currently smoke and who have smoked one pack of cigarettes a day for 10 years or more have an increased risk of estrogen receptor-positive breast cancer compared to young women who have smoked for a shorter period of time.
References
Contralateral mastectomy and survival after breast cancer in carriers of BRCA1 and BRCA2 mutations: retrospective analysis: http://www.bmj.com/content/348/bmj.g226
For women with BRCA gene mutation, ‘double mastectomy better’: http://www.medicalnewstoday.com/articles/272454.php
Image Credits
Woman with Arms Crossed Over Chest: http://www.freeimages.com/photo/1045658
