Prophylactic mastectomy for the prevention of breast cancer
Also called mastectomy, elective. The use of prophylactic bilateral and contralateral mastectomies is steadily increasing in the United States. Prophylactic mastectomy can be bilateral in healthy women at high risk of breast cancer, or unilateral if performed for a non-invasive breast lesion or in addition to a therapeutic mastectomy in the contralateral breast.
The rate of prophylactic mastectomy in women at high risk of breast cancer had increased during the years between 2004 and 2008 to reach 35.7% for bilateral mastectomy and 22.9% for contralateral mastectomy.
Prophylactic mastectomy could be technically performed in different ways. Total mastectomy (also called simple mastectomy) is a procedure in which most of the breast tissue, including the nipple-areola complex, is removed through an elliptical skin incision, but the muscle tissue beneath the breast is spared and the axillary lymph nodes. It is unlikely that all breast tissue will be eradicated; although, all visible breast tissue is removed.
Some breast tissue may unintentionally remain under the skin, in the inframammary fold, or near the armpit fat pad. In addition to total mastectomy, skin-sparing mastectomy is a way to remove breast tissue, including the nipple-areolar complex, through a periareolar incision, leaving most of the skin over the breast intact. This facilitates reconstruction and the skin of the breast is preserved without scars. As an extension of skin-sparing mastectomy, nipple-sparing mastectomy (also called total skin-sparing mastectomy) preserves the nipple-areolar complex and the skin over the breast. This is usually accomplished through an inframammary incision where the skin is carefully dissected from the breast until all anatomical limits of the breast are reached and the breast is removed in its entirety. It is important to avoid leaving breast tissue behind the nipple-areola complex.
This process is technically demanding and requires a lot of effort to reach the deepest limits of the breast through a small, deep incision. Specific retractors with light sources can be used to facilitate excision. Historically, skin-sparing mastectomy was more often preferred than total mastectomy. Today, total mastectomy is the preferred prophylactic procedure, due to the advantage of current nipple reconstruction techniques. Skin-sparing mastectomy was preferred more frequently than total mastectomy. Today, total mastectomy is the preferred prophylactic procedure, due to the advantage of current nipple reconstruction techniques. Skin-sparing mastectomy was preferred more frequently than total mastectomy. Today, total mastectomy is the preferred prophylactic procedure, due to the advantage of current nipple reconstruction techniques.
The increasing rate of postoperative complications, in addition to the doubtful oncological safety of nipple-sparing mastectomy, generated reluctance among some institutions and surgeons to adopt this technique. In general, there is still debate about the most appropriate type of mastectomy for high-risk women, and it should be selected carefully.
Impact of bilateral prophylactic mastectomy on breast cancer incidence
BRCA
In BRCA gene mutation carriers, several studies showed a significant reduction in the incidence of breast cancer in women who underwent bilateral prophylactic mastectomies. In 2001, Meijers-Heijboer et al . conducted a prospective cohort study of 139 women carrying mutations in the BRCA1 or 2 gene. Seventy-six (55%) of these women underwent prophylactic bilateral simple mastectomy, while the other 63 (45%) women remained under surveillance. . As a result of a mean follow-up period of 2.9 years, none of the 76 women who underwent prophylactic mastectomy developed breast cancer, compared with 8 cases of breast cancer diagnosed in the surveillance group (proportion of cases observed to expected, 1.2; 95 % confidence interval, 0.4–3.7). In the same year, Hartmann et al. . They identified 26 women with a BRCA1 or 2 gene mutation from their previous retrospective cohort study of bilateral prophylactic mastectomies. None of the patients developed breast cancer during a median follow-up of 13.4 years after prophylactic mastectomies. Using two models, these studies show an 85% to 100% risk reduction achieved by prophylactic mastectomy. Furthermore, in 2004, Rebbeck et al. .[] conducted a prospective cohort study of 483 women from the same risk group.
One hundred and five of these women who underwent bilateral prophylactic mastectomy were compared with 378 controls who did not undergo prophylactic surgery. With a mean follow-up of 6.4 years, breast cancer was found in two patients (1.9%) in the bilateral prophylactic mastectomy arm and in 184 (48.7%) in the matched control arm, confirming a reduction 90% to 95% in breast Cancer risk after bilateral prophylactic mastectomy. In a recent large prospective cohort study, Domchek et al. ] evaluated the relationship between prophylactic mastectomy and breast cancer outcomes in carriers of mutations in the BRCA1 and 2 genes. No breast cancers were observed in 257 women who underwent bilateral prophylactic mastectomy compared with 7% of women without surgery during the 3 years of follow-up, showing a decreased risk of breast cancer in carriers of BRCA1 and 2 gene mutations associated with bilateral prophylactic mastectomy . Additionally, in a 2015 study, 63 women carrying the BRCA1 or 1 gene mutation who underwent prophylactic nipple-sparing mastectomy reported no newly diagnosed breast cancers at a median follow-up of 26 months, supporting the same conclusion.[