Large studies suggest that the overall rate of
lymphoma in women with
breast implants is no greater than in the general population; clinical reports suggest an association between
breast implants and the rare
non-Hodgkin lymphoma,
anaplastic large cell lymphoma (ALCL). Observed cases of
lymphoma reported in Allergan-sponsored
breast implant clinical studies were compared with expected cases on the basis of the incidence of
lymphoma among women in the National Cancer Institute's Surveillance Epidemiology and End Results program, using standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). In clinical studies, there were 28 observed cases of
lymphoma among 89 382 patients and 204 682 person-years of follow-up compared with 43 expected cases [SIR: 28/43=0.65 (95% CI: 0.43-0.94), P=0.02]. SIRs were calculated stratifying by baseline
cancer history: women without prior
cancer [SIR: 17/24=0.70 (95% CI: 0.41-1.13), P=0.17] and women with prior
cancer [SIR: 11/14=0.79 (95% CI: 0.39-1.41), P=0.52]. SIRs were calculated by implant shell type: textured shell implants [SIR: 16/23=0.70 (95% CI: 0.40-1.13), P=0.16] and smooth shell implants [SIR: 12/19=0.63 (95% CI: 0.33-1.10), P=0.12]. Surveillance Epidemiology and End Results reported 12 cases of primary breast ALCL in women between 1996 and 2007 without a history of
cancer, for an average annual incidence of 4.28 (95% CI: 3.51-5.05)/100 million women in the US - these women may or may not have
breast implants. In clinical studies, three ALCL cases were reported in women with
breast implants and a history of
breast cancer, yielding a crude incidence rate of 1.46 (95% CI: 0.30-4.3)/100 000 person-years. Large clinical studies, based on over 200 000 person-years of follow-up, suggest no evidence of an increased risk of
lymphoma among women who have received
breast implants.