Silicone Breast Implants, Breast Cancer and Specific Connective Tissue Diseases: A Systematic Review of the Data in the Epidemiological Literature

Silicone Implant Illness: Science versus Myth?

The purpose of this Special Topic article is to present the current state of scientific evidence related to the safety of silicone breast implants. There is presently overwhelming evidence to support the safety of silicone breast implants. Ultimately, the decision to obtain, keep, or remove breast implants is the choice of the patient. If a patient chooses to have her breast implants removed, it is important to find a board-certified plastic surgeon with expertise in breast surgery. Ongoing studies are strongly encouraged in all areas, from cancer detection to autoimmune disease, as we strive for improved patient safety, patient awareness, and patient education. To the best of our body of scientific knowledge to date, there have not been any concrete or evidence-based studies or peer-reviewed data concerning the formation of a new syndrome: "silicone implant illness." Silicone breast implants are used in nearly 300,000 breast augmentation and 100,000 breast reconstruction operations annually in the United States. Silicone gel-filled implants were first approved by the U.S. Food and Drug Administration in 1962. Since that time, few medical devices have been studied as closely for their safety and associated adverse outcomes. Despite multiple generations of implant shells and gel fillers, the basic components remain as originally designed.

Silicone breast implants and connective tissue disease: no association

The association of silicone breast implants with connective tissue diseases (CTDs), including systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and fibromyalgia, as well as a hypothesized new "atypical" disease, which does not meet established diagnostic criteria for any known CTD, has been extensively studied. We have reviewed the epidemiologic literature regarding an association between cosmetic breast implants and CTDs, with particular emphasis on results drawn from the most recent investigations, many of which are large cohort studies with long-term follow-up, as well as on those studies that address some of the misinformation and historically widespread claims regarding an association between breast implants and CTDs. These claims have been unequivocally refuted by the remarkably consistent evidence from published studies, as well as numerous independent meta-analyses and critical reviews, which have demonstrated that cosmetic breast implants are not associated with a subsequent increased occurrence of individual CTDs or all CTDs combined, including fibromyalgia. Moreover, there is no credible evidence for the conjectured excess of "atypical" CTD among women with cosmetic breast implants, or of a rheumatic symptom profile unique to these women. No increased risk of CTDs is evident in women with extracapsular ruptures in two studies, which evaluated risk by implant rupture status, and no consistent association has been observed between silicone breast implants and a variety of serologic markers or autoantibodies. Thus, any claims that remain regarding an association between cosmetic breast implants and CTDs are not supported by the scientific literature but rather are a residual byproduct of the unprecedented large-scale product liability litigation in the USA.

A Nationwide Study of Connective Tissue Disease and Other Rheumatic Conditions Among Danish Women With Long-Term Cosmetic Breast Implantation

PURPOSE

Numerous epidemiologic studies have demonstrated that breast implants are not associated with connective tissue diseases (CTDs). However, many CTDs are rare, and continued follow-up of women with breast implants is warranted.

METHODS

We extended by 5 years the follow-up of our earlier population-based cohort study of Danish women with cosmetic breast implants (n = 2761) and comparison groups of women with other types of cosmetic surgery (n = 8807). All women were followed from January 1977 through December 2001. Hospitalization and outpatient data for CTD and ill-defined and other rheumatic conditions in the implant and comparison groups were compared with those in the general Danish population. Additionally, CTDs and fibromyalgia were confirmed through medical chart review, and direct comparisons of the breast implant cohort with the comparison cohort were performed.

RESULTS

When compared with general population rates, CTDs were not statistically significantly elevated in either the implant or the comparison cohorts. However, unspecified rheumatism was similarly increased in the implant (standardized rate ratio = 1.9; 95% confidence interval = 1.6 to 2.2) and comparison (standardized rate ratio = 1.5; 95% confidence interval = 1.4 to 1.7) cohorts. In analyses of diagnoses validated by chart review, women with cosmetic breast implants compared with those having other types of plastic surgery or consultation for plastic surgery had no statistically significant excess for any specific confirmed CTD or combined CTDs (hazard ratio = 1.3; 95% CI = 0.9 to 1.9). In addition, there was no relation between breast implants and confirmed fibromyalgia (hazard ratio = 1.2; 95% CI = 0.6 to 2.1).

CONCLUSIONS

This extension of our earlier cohort study further supports the consensus of epidemiologic research that breast implants are unrelated to the development of CTD.

Categorizing mistaken false positives in regulation of human and environmental health

One of the concerns often voiced by critics of the precautionary principle is that a widespread regulatory application of the principle will lead to a large number of false positives (i.e., over-regulation of minor risks and regulation of nonexisting risks). The present article proposes a general definition of a regulatory false positive, and seeks to identify case studies that can be considered authentic regulatory false positives. Through a comprehensive review of the science policy literature for proclaimed false positives and interviews with authorities on regulation and the precautionary principle we identified 88 cases. Following a detailed analysis of these cases, we found that few of the cases mentioned in the literature can be considered to be authentic false positives. As a result, we have developed a number of different categories for these cases of "mistaken false positives," including: real risks, "The jury is still out," nonregulated proclaimed risks, "Too narrow a definition of risk," and risk-risk tradeoffs. These categories are defined and examples are presented in order to illustrate their key characteristics. On the basis of our analysis, we were able to identify only four cases that could be defined as regulatory false positives in the light of today's knowledge and recognized uncertainty: the Southern Corn Leaf Blight, the Swine Flu, Saccharin, and Food Irradiation in relation to consumer health. We conclude that concerns about false positives do not represent a reasonable argument against future application of the precautionary principle.

Silicone breast implants and connective tissue disease: an updated review of the epidemiologic evidence

Numerous meta-analyses, weight-of-the-evidence, and critical reviews have summarized data from case-control and cohort studies, published through 1999, which have been conducted to evaluate the potential association between cosmetic silicone breast implants and the occurrence of well-defined connective tissue diseases, as well as a hypothesized new atypical disease, which does not fulfill established diagnostic criteria for any known connective tissue disease. These reviews have unanimously concluded that there is no evidence of an association between breast implants and any of the traditional connective tissue diseases evaluated individually or combined or atypical connective tissue disease. We have performed an updated review of the results of epidemiologic studies published since 1999. Two long-term follow-up studies of women with breast implants in Denmark and a retrospective cohort study in Australia found no excess of definite connective tissue disease, including rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus and Sjogren's syndrome, among women with cosmetic breast implants compared with breast reduction or other plastic surgery controls or women in the general population. No consistent evidence was observed of increased risk of definite connective tissue disease in women with extracapsular ruptures in 2 studies which evaluated risk by rupture status among women with cosmetic breast implants. The results of several studies provide no evidence of a higher frequency of undefined connective tissue disease among women with cosmetic breast implants or of a rheumatic symptom profile unique to these women and/or indicative of a specific atypical connective tissue disease. In conclusion, the most recent epidemiologic investigations have been remarkably consistent with earlier epidemiologic studies in finding no evidence of an excess of any individual connective tissue disease or all connective tissue diseases combined, including both established and atypical or undefined connective tissue disease, among women with cosmetic silicone breast implants. Thus, the conclusions reached in earlier independent reviews have not changed based on data published during the subsequent years.