Partial Mastectomy Versus Oncoplastic Breast Surgery; A Comparison of Outcomes Using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Database

PURPOSE: Oncoplastic surgery (OPS) procedures involve the application of principles of volume displacement/replacement to minimize contour deformity following partial mastectomy for breast cancer. To date, OPS has been associated with improved cosmetic outcomes and improved patient satisfaction, and has been reported as oncologically safe. Accordingly, OPS techniques are increasingly being adopted by breast cancer and plastic surgeons. We queried a national database to investigate how complication rates from OPS compares to those associated with partial mastectomy alone in the United States. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was used to extract data on all female patients with breast cancer who partial mastectomy with or without OPS between, 2005-2019. Partial mastectomies were defined as procedures coded using current procedural terminology (CPT) codes (19301, 19160, 19162), with OPS defined as procedures including concomitant codes for soft tissue transfer. Demographics and postoperative outcomes were compared between groups using T- and chi-squared tests. Factors predictive of postoperative morbidity were identified by multivariable logistic analyses. The false discovery rate (FDR) was controlled for at the 5% level to diminish confounding effects and odds ratios were adjusted for comorbidities. RESULTS: Of total of 346,915 procedures were identified for inclusion, 38% (n=130,270) incorporated OPS. OPS case volume significantly increased from 244 cases in 2005/2006 to 20,410 cases in 2019 (Fig.1). OPS patients were younger, less likely to report tobacco use, less likely to have COPD or diabetes, and more likely to have received neoadjuvant chemotherapy than patients treated without OPS. Radiation therapy did not differ between groups. OPS operations tended to be longer, but hospital stays tended to be shorter; specifically, OPS operations lasted 61 minutes longer than partial mastectomy (95%CI: 60.1-62.2 min, p<0.001) and OPS patients were discharged 0.67 days earlier from hospital (95%CI: 0.65-0.69, p<0.001). The most significant independent predictor of morbidity probability was OPS (controlling for diabetes, radiation therapy, chemotherapy, COPD, smoking status); morbidity was 10.7% lower in patients who had OPS (95%CI: 10.3-11.0, p<0.001). Despite OPS involving longer procedures with greater tissue manipulation, OPS patients were 52.4% less likely to suffer wound dehiscence (p<0.001) and 21% less likely to suffer a wound infection (p<0.001). However, while statistically significant, a 10% reduction in the small absolute complication rate (0.67%) decreases the clinical significance of this finding. Rates of re-operation, readmission, sepsis, and wound closure did not significantly differ between patient groups. CONCLUSION: OPS is increasingly performed in the US. This analysis demonstrates OPS is not associated with an increased rate of complications compared to partial mastectomy alone. Consequently, OPS represents a safe and effective strategy for eligible women with breast cancer. Applying techniques that utilized pedicled flaps, while still minimizing soft tissue tension and reduce dead-space do not increase operative risk and may improve cosmetic and patient-reported outcomes following breast cancer surgery. The success of OPS highlights how this is one area where plastic surgeons can collaborate with their breast surgeon colleagues to optimize outcomes for breast cancer survivors.