No abstract

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.

The lymphatic vasculature has traditionally been thought to play a passive role in the regulation of immune responses by transporting antigen presenting cells and soluble antigens to regional lymph nodes. However, more recent studies have shown that lymphatic endothelial cells regulate immune responses more directly by modulating entry of immune cells into lymphatic capillaries, presenting antigens on major histocompatibility complex proteins, and modulating antigen presenting cells. Secondary lymphedema is a disease that develops when the lymphatic system is injured during surgical treatment of cancers or is damaged by infections. We have used mouse models of lymphedema in order to understand the effects of chronic lymphatic injury on immune responses and have shown that lymphedema results in a mixed T helper cell and T regulatory cell (Treg) inflammatory response. Prolonged T helper 2 biased immune responses in lymphedema regulate the pathology of this disease by promoting tissue fibrosis, inhibiting formation of collateral lymphatics, decreasing lymphatic vessel pumping capacity, and increasing lymphatic leakiness. Treg infiltration following lymphatic injury results from proliferation of natural Tregs and suppresses innate and adaptive immune responses. These studies have broad clinical relevance since understanding how lymphatic injury in lymphedema can modulate immune responses may provide a template with which we can study more subtle forms of lymphatic injury that may occur in physiologic conditions such as aging, obesity, metabolic tumors, and in the tumor microenvironment.

No abstract