Study adds nothing to knowledge of processes of tissue injury induced by silicone

EDITOR—In a study that was five years old at publication Nyrén et al claim to show “no evidence of association between breast implants and connective tissue disease,” using classical rheumatic diseases as end points.1 This report is less comprehensive than that by Gabriel et al, although comparable in scope and shortcomings of definitions.2 It lacks data on rupture (the prevalence rises with time3); rupture enhances the reaction to gel filled devices.4 Gabriel et al estimated the minimum population necessary for risk assessment to be 62 000 subjects with implants and 124 000 controls.2

Table 3 is confusing because the observed numbers of cases are compared with the expected numbers, derived from the standardised hospitalisation ratios. The data can mean only that in Sweden the rate of admission to hospital for rheumatic disease is the same whether a patient has silicone implants or not. Few patients go to hospital for rheumatic assessment in the United States. We have admitted none for rheumatic disease over the past two years from our silicone clinic; not all removals of implants are done in hospital.

Adjustments for pre-existing diagnosis or miscoding do not seem to fit between tables 3 and 5; the total of individual defined disorders exceeds that for all patients by about a third, which is the frequency of overlap syndrome. Overlap syndrome has been ignored in this …