Implants come in various levels of texturation. Some brands have just a very slight roughness, while others are designed to stick to the surrounding tissue, using a “velcro effect.” A study from July 2018 reported that the higher surface area on the most heavily textured implants allows the accumulation of a higher biofilm load.7 Implants with less dramatic texturing had lower surface area and a correspondingly lower biofilm load. These biofilms may contribute to an ongoing immune reaction that doesn’t cause an acute sickness, but eventually could lead to ALCL. Interestingly, the following note appeared in the disclosure section of this study: “In the past, these authors have performed similar testing services for Allergan, Inc.”4
However, the majority of the studies conducted so far on BIA-ALCL have been retrospective, cautioned Roberto Miranda, MD, pathologist at The University of Texas MD Anderson Cancer Center, Houston. And because the type of implant isn’t known in all cases, he says, researchers are trying to construct an explanation for the disease from incomplete information. “What would be ideal would be a prospective study,” he told Cancer Therapy Advisor. By following groups of patients who have either smooth or textured implants over a period of years and comparing the relative incidence of BIA-ALCL, “if you see a difference, then you have epidemiologic evidence that textured [implants], in fact, are more associated with the lymphoma than the nontextured.” A prospective study would also help bring to light any other contributing factors, he says.
ALCLs are classified as ALK-positive or -negative, depending on whether they carry the ALK driver mutation. BIA-ALCLs are ALK-negative and CD30-positive. Unlike other T-cell lymphomas, BIA-ALCL generally remains localized to the area around the implant, rather than in lymph nodes throughout the body.
Patients with BIA-ALCL have an excellent prognosis, and surgical removal of the implant and the entire surrounding capsule of scar tissue is generally sufficient to cure the disease with a 98.8% 5-year overall survival rate.4 If the disease is completely contained within the capsule, the survival rate is 100%, but that rate drops to 72% if the cancer extends beyond the capsule. Similarly, prognosis is much better if no tumor mass is present, but only a buildup of fluid around the implant.
The LYSA study showed similar results, with 67% of patients presenting with effusion only and 23% with a tumor mass. Half of the patients (5 out of 9) with a mass had an infiltrative tumor type, compared with a quarter of patients with effusion only (6 of 26).