Breast Implant-associated Anaplastic Large Cell Lymphoma Incidence: Determining an Accurate Risk.

[OBJECTIVE] This study sought to estimate the incidence and incidence rate of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) at a high-volume single institution, which enables vigorous long-term follow-up and implant tracking for more accurate estimates.

[SUMMARY BACKGROUND DATA] The reported incidence of BIA-ALCL is highly variable, ranging from 1 in 355 to 1 in 30,000 patients, demonstrating a need for more accurate estimates.

[METHODS] All patients who underwent implant-based breast reconstruction from 1991 to 2017 were retrospectively identified. The incidence and incidence rate of BIA-ALCL were estimated per patient and per implant. A time-to-event analysis was performed using the Kaplan-Meier estimator and life table.

[RESULTS] During the 26-year study period, 9373 patients underwent reconstruction with 16,065 implants, of which 9589 (59.7%) were textured. Eleven patients were diagnosed with BIA-ALCL, all of whom had a history of textured implants. The overall incidence of BIA-ALCL was 1.79 per 1000 patients (1 in 559) with textured implants and 1.15 per 1000 textured implants (1 in 871), with a median time to diagnosis of 10.3 years (range, 6.4-15.5 yrs). Time-to-event analysis demonstrated a BIA-ALCL cumulative incidence of 0 at up to 6 years, increasing to 4.4 per 1000 patients at 10 to 12 years and 9.4 per 1000 patients at 14 to 16 years, although a sensitivity analysis showed loss to follow-up may have skewed these estimates.

[CONCLUSIONS] BIA-ALCL incidence and incidence rates may be higher than previous epidemiological estimates, with incidence increasing over time, particularly in patients exposed to textured implants for longer than 10 years.