S. R. DeBiase1, W. Sun2, C. Laronga2, D. Boulware3, J. K. Lee3, M. Lee2 1University Of South Florida College Of Medicine,Tampa, FL, USA 2Moffitt Cancer Center And Research Institute,Moffitt Breast Program,Tampa, FL, USA 3Moffitt Cancer Center And Research Institute,Moffitt Biostatistics,Tampa, FL, USA
Introduction: Contralateral prophylactic mastectomy (CPM) at the time of unilateral breast cancer surgery is increasing. In BRCA+ carriers, CPM reduces contralateral breast cancer risk and is cost-effective, but the cost benefit of CPM in BRCA- patients is controversial. We reviewed breast cancer patients treated with mastectomy and immediate reconstruction; our aim was to evaluate abnormal followup breast imaging and subsequent breast cancers in patients receiving CPM versus unilateral mastectomy (UM) with surveillance.
Methods: An IRB approved, retrospective, case-controlled, single-institution chart review of breast cancer patients receiving mastectomy and immediate reconstruction from Jan 1990 – May 2013 was performed. Cases were matched 1:1 by reconstruction type and age (+/- 5 years) to limit procedure and age-related confounding variables. Patients with delayed mastectomy, delayed reconstruction, or bilateral cancer diagnosis at surgery were excluded. Staging, pathology, genetic, diagnostic imaging, and outcome data were collected. Therapeutic mastectomy date was used as the reference timepoint. Univariate statistical analyses using SAS (v. 9.4) employed Fisher’s exact test, Wilcoxon Rank Sum, Kruskal Wallis, and Log-Rank tests.
Results: Forty-five UM cases were matched to bilateral mastectomy (BM). Mean age (n = 90) was 52.2 years (range 21.5-74.9) with mean followup time of 7.1 years (range 0.2-19.8).There was no significant difference between UM and BM with regards to BMI, pathologic stage, follow up time, distant recurrence and survival. Genetic status was available for 31.1% of cases; 5 women were BRCA+ and had BM. Six UM and 11 BM patients had abnormal followup breast imaging. Of these, 5 UM and 5 BM patients had abnormal imaging contralateral to the original cancer. Six UM and 10 BM patients had breast/chest wall biopsies after abnormal imaging, with 5 and 4 contralateral biopsies after 4.3 years (range 7.0-0.6) and 4.2 years (range 7.3-1.1) respectively. One UM patient developed contralateral cancer; 5 BM patients had local recurrence. Two UM and 5 BM patients had distant recurrences. Twenty-one UM and 16 BM patients complained of contour/asymmetry after mastectomy, 17 UM and 26 BM did not; 7 UM and 3 BM patients did not report cosmesis (P=0.18, Fisher’s Exact test).
Conclusion: Our results demonstrate the low frequency of contralateral abnormal imaging in UM patients and extremely low incidence of contralateral breast cancer with close followup. More patients with CPM had new abnormal imaging and biopsies, although this was not statistically significant. Thus, CPM did not reduce contralateral imaging/biopsies and additional biopsies may actually be related to CPM with reconstruction.
