Impact of breast implants on surgical and oncologic outcomes in breast cancer patients

Background: Breast augmentation is one of the most common cosmetic surgeries, with nearly 300,000 performed in the U.S. annually. While breast augmentation is common, little is known about how prior implants impact surgical management in breast cancer (BC). To our knowledge, no large study has compared the likelihood of mastectomy or oncologic outcomes between patients with and without implants. Our objective was to evaluate whether breast implants influence the likelihood of mastectomy and to compare oncologic outcomes following breast-conserving surgery (BCS) between patients with and without prior implants. We hypothesize that BC patients with prior implants are more likely to receive a mastectomy due to smaller breast size, proximity of a lesion to the implant capsule, or fear of capsular contraction after radiation. Furthermore, we hypothesize that the risk of recurrence and overall survival (OS) with BCS is no different with or without implants. Methods: We used the TriNetX database on November 1, 2024 to conduct a retrospective search for women ≥18 years old diagnosed with BC. Stage IV and T4 BC patients were excluded. Two cohorts were created: those with non-autologous breast implants at least one year prior to BC diagnosis and those without, and the risk of mastectomy was determined. Patients’ propensity scores were matched based on age, body mass index (BMI), tobacco use, stage, tumor (T) size, radiation history, pregnancy status, genetic risk, and comorbidities. We then used the two previously created cohorts and added BCS to both. The same propensity score matching algorithm was used. Our outcomes of interest were 5-year local recurrence (LR) and OS using the Kaplan-Meier (KM) analysis. Results: A total of 880,575 patients without implants and 31,794 patients with implants were identified, resulting in 28,414 patients per cohort after matching. Matched patients without implants had a higher risk of mastectomy compared to patients with implants [odds ratio (OR) 5.6, 95% confidence interval (CI): 5.17–6.16, P<0.0001]. For our second study, 168,684 BCS patients without implants and 10,792 BCS patients with implants were identified, with 10,043 patients per cohort after matching. Patients without implants who underwent BCS showed no difference in 5-year OS (KM analysis: 93.7% vs. 93.5%, P=0.50) and LR (OR 0.82, 95% CI: 0.64–1.05, P=0.12). Conclusions: Matched stage I–III, T1–T3 BC patients with prior breast augmentation are not more likely to receive a mastectomy compared to nonaugmented patients for BC treatment. Furthermore, those who undergo BCS do not have a higher risk of mortality or LR than their matched cohort without implants. We conclude that breast implants should make no difference in the decision for mastectomy or BCS.