Mastectomy is removal of breast tissue to treat or prevent breast cancer. “Unilateral mastectomy” is the surgical removal of one breast. “Bilateral mastectomy” is the removal of both breasts. “Prophylactic mastectomy” refers to the removal of healthy breasts to reduce a woman’s risk of developing breast cancer. Bilateral prophylactic mastectomy is the most effective means of reducing a woman’s risk; however, the benefits of such surgery depend on each woman’s individual risk. Because even the most experienced breast surgeon cannot remove all breast tissue, a small risk of developing breast cancer remains after prophylactic mastectomy. Although effective, some consider prophylactic mastectomy to be a drastic way to lower cancer risk. A woman’s decision to remove her healthy breasts is highly personal. Confronting your personal cancer risk can be confusing and frustrating. If you are a high-risk woman trying to choose the best risk-management option, you need a clear sense of your personal risk as possible and an understanding of the potential benefits, risks and side effects of prophylactic surgery. Therefore it is important to consult with a specialist in cancer genetics when determining your risk for breast cancer and making risk-management decisions that are best for you. Stay in contact with a genetics expert for updates on current knowledge.
Study data shows prophylactic mastectomy is effective, reducing the chance of developing breast cancer by as much as 95% in high-risk women. A 1998 study of 639 women at high or moderate risk for breast cancer found prophylactic mastectomy reduced their risk by 90%, compared to their sisters who did not undergo the procedure. (The study did not look specifically at women with BRCA mutations; the surgeries were done prior to the availability of genetic testing.) Seven participants developed breast cancer after prophylactic mastectomy. A later study which included genetic testing on the same 639 women determined a similar risk reduction from prophylactic surgery in the 18 mutation carriers identified. These studies were limited—they were retrospective, meaning researchers looked at past records from women who had undergone this procedure. In a more recent study when researchers followed BRCA carriers for 6 years after bilateral mastectomies, they discovered mastectomy surgery alone lowered the risk for breast cancer by about 90%. Risk reducing surgery in women who had both bilateral mastectomies and oophorectomies (removal of the ovaries) reduced risk by 95%.
A generation ago, mastectomy meant one thing: removal of the breast and chest muscle. Today, different types of mastectomy are available. Sometimes circumstances determine which mastectomy is best for a patient, particularly when there is already a diagnosis of breast cancer. Further, the type of mastectomy may affect a woman’s options for reconstruction. When mastectomies are performed prophylactically, reconstruction can be done at the same time. This “immediate reconstruction” has cosmetic advantages over “delayed reconstruction” which is performed anytime after mastectomy, and is sometimes necessary when mastectomy is recommended as treatment for breast cancer. It is important to discuss your mastectomy and reconstructive options with your surgeons. Understand the potential benefits, risks and limitations of each option before your surgery.
A modified radical mastectomy removes the entire breast and includes “axillary dissection” (removal of the lymph nodes from the armpit).
A simple mastectomy removes the entire breast but does not include axillary dissection. Only lymph nodes that might be located within the breast tissue are removed during a simple mastectomy.
Skin-sparing mastectomy is performed to facilitate immediate breast reconstruction. Skin-sparing mastectomy incisions are smaller than those required for a modified radical or simple mastectomy. Most of the breast tissue is removed, but most of the breast skin is saved to hold and shape the reconstructed breast. In a skin-sparing mastectomy, the incision is made around the areola. Sometimes it is necessary to make another incision extending down or to the side to remove as much breast tissue as possible. Research shows skin-sparing mastectomies do not increase the risk for breast cancer recurrence in patients with early stage breast cancer. A study on skin-sparing mastectomies in women with breast cancer did not find an elevated risk of recurrence with the skin-sparing mastectomy. A more recent, prospective study found similar recurrence rates, whether women with advanced stage breast cancer had skin-sparing mastectomy or modified radical mastectomy. Skin-sparing mastectomies are now commonly used for prophylactic mastectomy followed by immediate reconstruction.
Subcutaneous mastectomy is a type of skin-sparing mastectomy which removes tissue through an incision under the breast, leaving the skin, areola, and nipple intact. Some women who have prophylactic mastectomies prefer a subcutaneous procedure because it retains their nipples and offers very good cosmetic results. By working through the incision under the breast, the new breast is reconstructed without visible scars. Because a subcutaneous mastectomy leaves more tissue behind—working through the incision under the breast makes it impossible to remove as much tissue as a simple or modified radical mastectomy—this procedure is considered appropriate only as a prophylactic measure. Most physicians consider subcutaneous mastectomy inappropriate for women with large tumors, cancer of the breast skin, or with tumors under or near the nipple or areola. The subcutaneous procedure is different from a 'nipple-sparing mastectomy,” where there nipple is scraped free of breast tissue and replaced as a graft (see below).
In the 1998 study on prophylactic mastectomy in high-risk women, 90% of the mastectomies performed were “subcutaneous” mastectomies. However, of the seven women who did develop cancer after prophylactic mastectomy, all were in the subcutaneous mastectomy group. Although it is believed that there is more risk for breast cancer in the remaining tissue after subcutaneous mastectomy when compared with skin-sparing simple mastectomy, there is still a risk reduction with this surgery. The relative difference in risk reduction between subcutaneous mastectomy and simple mastectomy for mutation carriers is unknown. A recent review article discusses the relative risks and benefits of subcutaneous mastectomy as an option for prophylactic mastectomy in high risk women.
Nipple-sparing mastectomy is another type of skin-sparing procedure that allows a woman to retain her own areola and nipple. Unlike the subcutaneous mastectomy (incision is made at the bottom of the breast), the incision for a nipple-sparing mastectomy is made around the areola. Although both techniques conserve the nipple, a subcutaneous mastectomy leaves more breast tissue behind. In the nipple-sparing procedure, the nipple-areola is completely removed from the breast, scraped clean of tissue and regrafted back onto the breast. During the surgery, a sample of the patient’s tissue beneath the nipple is tested. If cancer cells are found, the entire nipple-areolar complex is removed. Removing and regrafting the nipple usually causes it to lose most, if not all of its normal sensation and can change and flatten its shape.
Sentinel node biopsy is a procedure to determine whether breast cancer cells have spread beyond the breast tissue. By injecting a blue dye or radioactive tracer (or both) into the breast, the surgeon can follow the lymph system from the tumor to the sentinel node, the first underarm node most likely to contain cancer cells if they have spread beyond the breast. Sentinel node biopsies are performed when invasive breast cancer is diagnosed. If the sentinel node is found to be clear of cancerous cells, a woman is spared the more conventional “axillary dissection,” a more invasive surgery to remove many of the underarm lymph nodes. Axillary dissection can cause “lymphedema,” an uncomfortable, long-term complication caused by fluid build-up in the arm.
Prophylactic mastectomy does not typically include either sentinel node biopsy or axillary dissection because the woman is assumed to be free of breast cancer. However, because breast cancer is found in a small percentage of high-risk women during prophylactic mastectomy, some breast surgeons perform sentinel node biopsy as a precautionary measure, to spare women the more extensive axillary dissection if cancer is found. If invasive breast cancer is found during prophylactic mastectomy, the surgeon samples underarm lymph nodes to see if the disease has spread, and to determine appropriate treatment.
One small study looked at sentinel node biopsy in 143 women who had prophylactic mastectomies. In this study, four women had invasive cancer found at the time of the prophylactic mastectomy: two had positive sentinel nodes, while two had negative sentinel nodes. The two women who had a negative sentinel node biopsy at the time of their mastectomy were able to avoid further axillary dissection. Women considering prophylactic mastectomy should discuss the benefits, risks and limitations of sentinel node biopsy with their surgical team.
Every surgery has potential risks; some are more serious than others. Some mastectomy risks can affect recovery. Others can affect the type of scarring and appearance of the breast reconstruction. Some possible risks include:
- Fluid build-up at the surgical site (seroma or hematoma)
- Delayed healing
- Blood loss
- Blood clots
- Pain (post-operative and long term pain syndromes)
It is important to discuss possible surgical risks with your physician. Understand the seriousness and likelihood of these risks prior to surgery.
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