Current Knowledge on Breast Implant-Associated Anaplastic Large Cell Lymphoma: Evidence from Italian Ministry of Health Registry Data

Background: Accurate estimation of Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) incidence is crucial for assessing breast-implant-associated risk. However, the size of the implanted population worldwide is unknown, making it challenging to appropriately estimate this figure. This study aims to provide a new reliable and reproducible method to estimate the breast-implanted-population (BIP), reporting a reliable annual BIA-ALCL incidence estimate. Moreover, we discuss all activities performed over the past decade in collecting complete histories, managing, and monitoring outcomes of each Italian case. Methods: Data from the National Breast Implant Registry and from manufacturers have been used to define a new formula to estimate the BIP at risk of developing a breast implant-related event. From the BIA-ALCL registry, complete information on Italian cases has been collected and analysed. Overall survival is estimated by the Kaplan-Meier curve. Results: From 2010 to June 2024, 111 BIA-ALCL cases were recorded in Italy. The estimated incidence rate showed an upward trend, ranging from 2.68 to 6.35 cases per 100,000 patient-years. Thanks to newly promoted disease awareness, most patients had a complete response to treatment, resulting in a three-year overall survival rate estimate of 98.2%. Conclusions: The BIP formula showed to be an innovative, effective and reproducible tool to make a reliable estimation of the implanted population, confirming that BIA-ALCL is a rare disease with an incidence rate estimate varying from 2.7 to 6.3 cases/100.000 patient-years in the last five years. Eleven-year experience in this field also confirmed that this disease has a favorable prognosis if properly treated.