89th Annual Meeting Abstracts

PURPOSE:
Prophylactic mastectomy is increasingly being offered in the United States for breast cancer risk reduction. With improved ability to stratify a woman’s risk for breast cancer, this intervention is increasingly selected by patients at high-risk for cancer occurrence. However, outcomes research has lagged clinical enthusiasm for prophylactic mastectomy, and therefore a prospective Registry was created at Georgetown University Hospital to track outcomes of patients undergoing or considering prophylactic mastectomy.
METHODS:
A prospective Registry offers voluntary enrollment to all patients considering prophylactic mastectomy at Georgetown University Hospital starting in January, 2008. Patients that are enrolled are also offered to participate in a preoperative and postoperative quality-of-life survey. The Registry is IRB-approved and recorded as a clinical trial on the ClinicalTrials.gov website.
RESULTS:
After eighteen months of enrollment, 130 patients were found to be eligible, of whom 107 (82%) enrolled. A total of 105 prophylactic mastectomies were performed in 86 patients. Of those who had surgery, the prophylactic mastectomy was performed as a contralateral procedure (to therapeutic mastectomy) in 64 breasts, in a bilateral fashion in 21 patients (42 breasts), and as an isolated unilateral prophylactic mastectomy in 1 patient. Fifteen patients (17%) were BRCA1 or BRCA2 gene-mutation carriers, and an additional eleven patients (13%) had a strong family history of breast cancer. Thirty-three nipple-sparing mastectomies were performed in 25 patients (31% of prophylactic mastectomies); none of these patients had cancer or atypia in the subareolar button that is sent as a separate pathologic specimen. Twenty-six sentinel lymph node biopsies were performed (25% of mastectomies); all were negative for malignancy.
The patients’ reconstructive preferences were analyzed. Nine patients (9%) did not have any reconstruction. 65 breasts in 52 patients (62% of mastectomies) were reconstructed with tissue expanders and acellular dermis; an additional patient had one-stage bilateral reconstruction with implants and acellular dermis. Thirty-two breasts in 26 patients (30%) had autologous reconstruction, the majority of which were DIEP flaps.
Twenty-two of the breasts (21%) had significant incidental abnormal findings on pathologic examination of the mastectomy specimens. Five patients (5%) had intraductal carcinoma, one patient (1%) had infiltrating lobular carcinoma, and two patients (2%) had an internal mammary node with metastatic carcinoma. Eleven patients (10%) had atypical ductal or lobular hyperplasia.
Seventeen patients had postoperative complications (20%); the most common complications were cellulitis (six patients) and mastectomy flap necrosis (five patients). One patient (1%) had a pulmonary embolus that was managed with anticoagulation; there were no mortalities.
CONCLUSION:
Prophylactic mastectomy can be an effective risk reduction strategy in the high-risk patient, but it does carry potential postoperative complications of which patients need to be adequately informed. The incidence of occult pathologic findings that are particularly worrisome in this high-risk population is greater in this prospective study than has been reported elsewhere in the literature.