Does the Type of Reconstruction Matter? A Propensity Score Analysis of Immediate Postmastectomy Implant and Flap Reconstruction

Background: No randomized controlled trials have compared implant and flap reconstruction. Recently, worse longitudinal outcomes have been suggested for flap reconstruction. The authors compared long-term oncologic outcomes of postmastectomy breast reconstruction using propensity score matching. Methods: A retrospective study of postmastectomy reconstruction was achieved using the Weill Cornell Breast Cancer Registry between 1998 and 2019. Patients were matched using propensity scores based on demographic, clinical, and surgical characteristics. Kaplan-Meier estimates, Cox-regression models, and restricted mean survival times (RMST) were used to evaluate patient outcomes. Results: Before matching, 1395 implant and 586 flap patients were analyzed. No difference in overall survival and recurrence were observed. Multivariable models showed decreased survival for Medicare/Medicaid [hazard ratio (HR), 3.09; 95% CI, 1.63 to 5.87; P < 0.001], pathologic stage II (HR, 2.98; 95% CI, 1.12 to 7.90; P = 0.028), stage III (HR, 4.88; 95% CI, 1.54 to 15.5; P = 0.007), 11 to 20 lymph nodes positive (HR, 3.66; 95% CI, 1.31 to 10.2; P = 0.013), more than 20 lymph nodes positive (HR, 6.41; 95% CI, 1.49 to 27.6; P = 0.013). RMST at 10 years after flap reconstruction showed 2 months of decreased survival time compared with implants (9.56 versus 9.74 years; 95% CI, -0.339 to -0.024; P = 0.024). After matching, 563 implant and 563 flap patients were compared. Reconstruction was not associated with overall survival and recurrence. RMST between implant and flap reconstruction showed no difference in each 5-year interval over 20 years. Conclusion: Postmastectomy breast reconstruction was not associated with a difference in long-term oncologic outcomes over a 20-year period.