D15. Risk Factors Associated With BIA-ALCL Development: A Case Control Study

PURPOSE: So far etiology and risk factors associated to BIA-ALCL are only hypothesized. We aimed to identify variables significant for development. METHODS: an age-adjusted (±5 years) case-control (1:4) study (level II evidence) of 89 diagnosed BIA-ALCL cases (39±13 years) and 310 breast implant control patients (46±10 years), was conducted. Eighty clinical, demographic and life-style variables were analyzed by a conditional logistic regression to estimate their odds. RESULTS: All patients had an history of at least one exposition to implants roughness higher than 10µm. No association was observed between BI manufacturer (p=0.21). Replacement was associated with 43% lower odds (0.57, 95%CI 0.37-0.86). BI volume was positively associated with BIA-ALCL (per 100cc 1.65, 1.22-2.21). Compared to cosmetic augmentation, BIA-ALCL was less likely to occur in post-oncologic patients (0.01, 0.001-0.03). History of chemotherapy, radiotherapy, and hormone therapy showed respectively 88% (0.12, 0.06-0.23), 69% (0.31, 0.15-0.64) and 91% (0.09, 0.05-0.18) lower odds. Women who had stopped smoking were 39% less likely to have BIA-ALCL compared to smokers (0.61, 0.38-0.87). Autoimmune co-morbidities were associated with 2-times higher odds (2.01, 95%CI 0.76-5.35) and Hashimoto's Thyroiditis with 2,5-times higher odds (2.57, 95%CI 0.69-9.17). CONCLUSION: We confirm no BIA-ALC cases with history of implants with roughness only lower than 10µm. We could first demonstrate that BIA-ALCL more likely occurs in patients with higher implants volume, autoimmune co-morbidities, or cosmetic indication. While it occurs less likely with post-oncologic patients, chemotherapy, radiotherapy, hormone therapy and smoking abstention and with one or more replacements.