Epidemiology of Anaplastic Large Cell Lymphoma Associated with Breast Implants: a quantitative analysis

Background and Objective: Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a rare non-Hodgkin T-cell lymphoma arising in patients with breast reconstruction post-mastectomy or undergoing cosmetic-additive mammoplasty. Due to widespread use of implantations for cosmetic purposes, BIA-ALCL cases are expected to increase. We aimed at investigating main characteristics of the disease and factors predicting BIA-ALCL onset in patients with and without implant replacement. Method: A quantitative analysis was performed on cases extracted from primary studies published until April 2022 and searched in PubMed, Scopus and Google- Scholar databases, using “Breast-Implant” AND/OR “Associated” AND/OR “Anaplastic-Large-Cell-Lymphoma”. Statistical significance was verified by Student-T test for continuous variables, while Fisher’s exact test was applied for qualitative variables. Cox model with time-dependent covariates was applied to estimate BIA-ALCL’s onset time. Results: 232 patients with BIA-ALCL (mean age at diagnosis: 55 years-old; mean time to disease onset from first implant: 10.3 years) were extracted from 52 selected studies. Patients with cosmetic implants were younger than patients with post-mastectomy implants but no difference was showed for median time to onset. Patients with implant replacement were significantly older than patients without previous replacement at the diagnosis, having a median time to diagnosis since first implant of 13 years (7 years in patients without replacement). Hazard of developing BIA-ALCL resulted significantly lower inpatients having a previous implant replacement as compared to patients who did not (HR= 0.03; 95%CI: 0.005-0.19; p-value= <0.01). Conclusion: Exposure time to prosthesis, regardless of the age at implant and any possible condition associated with the disease, may play a role in BIA-ALCL induction. We provided evidence to be suggested for a proper information on breast implant use and for updating follow-up guidelines. Linkage between prosthetic implants registries and population-based cancer registries will help to better estimate the epidemiological impact over time of both BIA-ALCL and other lymphomas.