Trends and Histopathological Findings in Prophylactic Mastectomies: An 18 Year Retrospective Study.
Andy L Lo, Baljit Singh. New York University Langone Medical Center, NY
Background: The incidence in bilateral prophylactic mastectomies (BPM) and contralateral prophylactic mastectomies (CPM) for BRCA positive and high risk patients has increased in recent years. We examined the trend for these types of surgeries at our institution and compared histopathological findings with those of a reduction mammoplasty (RM) group.
Design: Pathology database at Tisch Hospital, NYULMC was searched for CPM and BPM between 1992 to 2009. Patients with no history of breast cancer who underwent RM were also identified. Reports were evaluated for indications for procedure, age and histopathological characteristics.
Results: We identified 446 patients who underwent CPM for breast cancer and 79 patients who underwent BPM for BRCA positivity. 1150 RM patients were identified over the same time period. The rate of all prophylactic mastectomies (CPM & BPM) increased from 4 cases in 1992 to 22 in 2004, and from 30 in 2005 to 114 in 2009.
By contrast, the number of RM showed variability depending on the year but remained approximately the same over time (average 60.5, median 61). The incidence of premalignant lesions was statistically higher in CPM & BPM (PM) groups than RM:
atypical ductal hyperplasia (51/525(PM) vs 13/1150 (RM), p=<0.001), and atypical lobular hyperplasia (56/525(PM) vs 24/1150(RM), p=<0.001), lobular carcinoma in situ (62/525(PM) vs 13/1150(RM), p=<0.001). Similarly, the incidence of malignant lesions was also statistically higher in the PM group: invasive carcinoma (5/525 (PM) vs 2/1150 (RM), p=<0.05), ductal carcinoma in situ (35/525 (PM) vs 5/1150 (RM), p=<0.001).
Conclusions: In this cohort we observed a marked increase in PM for high risk and BRCA-positive patients since 2005. This is the largest series of histopathological findings in PM specimens since this change in practice. A statistically significant incidence of premalignant and malignant lesions continues to be seen in PM as compared to RM.
Monday, February 28, 2011 1:00 PM
Poster Session II # 39, Monday Afternoon