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Updated: Jun 1, 2026
Endoscopic Bilateral Nipple-sparing Mastectomy via a Single Axillary Incision with Immediate Pre-pectoral Implant-based Breast Reconstruction
Published on: May 17, 2024
Prognosis of early-stage synchronous bilateral invasive breast cancer
S M Schmid1, C Pfefferkorn, M E Myrick
1Department of Gynecology and Obstetrics, University Hospital Basel, Spitalstrasse 21, CH-4031 Basel, Switzerland.
Background:
Contradictory data exists concerning the prognosis of patients with synchronous bilateral breast cancer (SBBC). Most authors report a worse prognosis for SBBC patients compared to unilateral breast cancer (UBC) patients. There are a few studies that did not support these findings. This study gives a comprehensive picture of SBBC and tests the hypothesis that outcome of this entity is based on the tumor with the worse prognosis (reference lesion).
Patients & Methods:
The data of two prospective Swiss breast cancer databases covering a 20-year period (1990-2009) was reviewed. Forty-six cases of SBBC were identified. In 34 patients with early-stage SBBC, the reference lesions (defined as the tumor with the more advanced stage or, in cases where both tumors had the same stage, the larger tumor) were compared in a case-control approach with 100 patients having UBC (SBBC/UBC ratio = 1/3). The controls were matched for age, time of diagnosis, tumor size, axillary node status, histological grade and estrogen-receptor status. Differences in terms of survival curves were analyzed using the log rank test; the possible correlation between matched groups was evaluated by a frailty Cox model.
Results:
There were no significant differences in disease-specific survival between SBBC and its unilateral controls (HR, 0.932; 95% CI, 0.322-1.07; p = 0.90).
Conclusions:
The prognosis of SBBC was determined by the reference lesion; the contralateral second tumor had no additional impact on outcome.
