Silicone breast implants and disease

Note: This report represents information on this subject as of December 1996.

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Resolution 506 (I-95), submitted by the American Association of Plastic Surgeons, American Society of Maxillofacial Surgeons, and American Society of Plastic and Reconstructive Surgeons, was adopted. It called for the AMA Board of Trustees to request the Council on Scientific Affairs (CSA) to update its report on breast implants through further review of the silicone breast implant literature, taking into account recent scientific information, and present their findings for dissemination.

The CSA submitted its first report (Report M, I-91) on the subject of silicone breast implants at the 1991 Interim Meeting, where it was adopted as amended (Policy 525.984, AMA Policy Compendium). At the 1992 Interim meeting, the CSA updated its policy in Report C (I-92), which was also adopted as amended (Policy 525.983).

AMA policy states that AMA (1) continues to support the establishment of a registry of all patients with breast implants, so that data pertaining to health outcomes can be regularly reviewed and reported to physicians and patients; (2) supports the position that women have the right to choose silicone gel-filled or saline-filled breast implants for both augmentation and reconstruction after being fully informed about the risks and benefits; (3) urges physicians be informed of the current scientific data available in order to recognize and address the considerable public anxiety concerning the safety of breast implants, an anxiety not warranted based on current scientific evidence; (4) supports the continued availability of silicone gel implants for both augmentation and reconstruction, provided that there is appropriate data collection and follow-up in all cases in which such implants are utilized, and that clinical trials as proposed by the FDA do not limit the woman's right to choose; (5) will monitor the process of decision-making by the FDA on the use of not only silicone gel breast implants but also all silicone-based devices, with particular attention to use of expert medical judgment and to issues of conflict of interest; and (6) requests that specific FDA policies regarding the process of evaluation of devices be developed and publicized to the medical profession and the public, and that the process be sensitive to the emotional impact on the patient. (Policy 525.983).

CSA panel

In November 1996, a panel of experts was convened by the CSA. The purpose of this meeting was to provide updated information about the current state of research. Information was received from the following experts:

Garry S. Brody, MD, MSc, FACS
Professor of Clinical Surgery (Plastic)
University of Southern California

Marc C. Hochberg, MD, MPH
Head, Division of Rheumatology and Clinical Immunology
University of Maryland School of Medicine

Noel Richard Rose, MD, PhD
Director of Immunology, Department of Pathology
The Johns Hopkins University School of Medicine

David Schottenfeld, MD, Msc
John G. Searle Professor of Epidemiology
University of Michigan School of Public Health

Of particular interest was the discussion by Dr. Rose of causality, as guided by the discussion of Lilienfeld and Stolley.¹ The knowledge gained by this experience was used to form a basis for reconsideration of the existing position of the CSA on silicone gel-filled breast implants. 

Cancer

Epidemiologic studies have tracked the relationship between breast implants and incidences of cancer, with follow-up periods ranging from 10 to 20 years.^2-4 No evidence of increased risk of cancer among recipients of silicone breast implants has been identified. One study suggests that women with breast implants may have a slightly lower relative risk of breast cancer, perhaps related to having smaller amounts of breast tissue than the general population of women or improved surveillance.

Before they were removed from the market in 1971, approximately 10 percent of women with implants received implants with a polyurethane foam covering.³ Over several years, this covering slowly hydrolyzes, yielding several breakdown products. One of these is 2,4,toluene diamine (TDA). TDA has been shown to produce hepatomas in one strain of cancer-prone mice. Manufacturers of the implant have provided data to the FDA indicating that trace amounts of TDA have been found in the urine of women with polyurethane-covered implants.⁵ After considering the results of this study, the FDA placed the risk of cancer from polyurethane foam-covered implants at about one in 1,000,000. The FDA advisory panel described this risk as "negligible," and FDA does not recommend that women with polyurethane-covered implants have them removed.³

Research has also examined the possibility that breast implants may impede early detection of breast cancer, as the implant is radio-opaque. Studies indicate, however, that the stage of breast cancer detection in women with implants is not significantly different than that of the overall population.⁶ Improved mammographic technology and techniques have also been developed, increasing the ability of mammograms to detect cancer among women with implants. The FDA recommends that women with implants conscientiously follow breast cancer surveillance methods as recommended for the general population, including regular mammography, breast self-examination, and clinical breast examinations.³

The Society for Breast Imaging, American Society of Plastic and Reconstructive Surgeons, and the American Cancer Society recommend that women with implants receive mammographic screening at facilities accredited by the American College of Radiology, which are familiar with the special techniques appropriate to screening breasts with implants.

Autoimmune disease

Since 1993, several large-scale studies have examined the possible relationship between silicone breast implants and connective tissue disease (CTD).^7-10 None of these studies found evidence of a relationship between silicone gel implants and definite CTD. Lingering questions persist about a possible relationship between silicone gel implants and undifferentiated CTD symptoms. The largest epidemiologic study¹⁰ found a small but significant statistical association between implants and self-report of any symptoms of CTD; when analyzed by specific CTD diagnosis, however, no statistically significant relationships were found. The authors of this study note in their discussion that "The data from this large retrospective cohort study are compatible with previous recent reports from two other cohort studies that provide reassuring evidence against a large hazard of breast implants on connective-tissue diseases,"¹⁰ and they state that before it can be concluded from this study that the observed statistical association between implants and CTD is meaningful, "the roles of chance, bias, and confounding must be assessed as possible alternative explanations." 

The FDA indicates in their 1996 review of breast implants that the recent human studies "provide substantial--but not complete--reassurance about the possible link between breast implants and autoimmune disorders."³  They characterize the evidence of a connection between silicone gel breast implants and rheumatologic disorders as "unconvincing."

In October 1995, the American College of Rheumatology issued a statement which concluded:

Known risks

Known surgical risks of implants (both silicone gel and saline) include those common to any surgical procedure, including hematoma, infection, and anesthesia complications. 

Known risks of implants include rupture, deflation, and leakage. Saline implants are more vulnerable to damage and deflation than silicone gel implants. Rupture of saline implants results in rapid deflation and harmless reabsorption of the saline by the body. Surgical removal and/or replacement may then be recommended. 

Rupture of silicone gel implants can result in changes in breast size, breast appearance, pain, burning, or changes in sensation. Some women appear to be asymptomatic when their silicone gel implants rupture. The exact rate of rupture is unknown, but estimates have ranged between 5 percent and 51 percent.³ In most cases, silicone "bleed" of fluid and silicone gel ruptures is confined to the implant capsule or the immediate capsule area. Some reports of migration beyond the capsule, into breast tissue, lymph nodes, or chest wall exist, particularly with regard to some of the very early implant models (1960s and early 1970s). With the possible exception of a specific magnetic resonance imaging technique, there are no uniformly reliable tests for diagnosing rupture in patients with implants. Ultrasound studies and some specially tailored mammographic studies are of selective value for some women. Another known risk of implants is capsular contraction, which is a constriction of the scar tissue envelope around the implant. This contracture can result in pain, hardening, or changes in appearance. Historically, some contractures have been treated by closed capsulotomy, which ruptures the scar envelope using squeezing pressure to the breast. While this provides subjective relief for some women, it increases the risk of implant herniation beyond the capsule wall, and closed capsulotomy is now rarely performed. 

Additional effects experienced by some women with implants are changes in nipple or breast sensation, calcium deposits in surrounding tissues, shifting, and increased difficulty in lactation. There has been one report, based on a small number of case studies, in which children nursed by women with implants experienced gastrointestinal disturbances.¹¹ This report has not been replicated. A subsequent study showed no difference in autoantibody production in children with gastrointestinal disorders born to women with or without implants.¹²

Laboratory testing

Some individuals and companies are marketing tests to detect silicone in the bodies of women who have had implants. The FDA states, "There is no widely available, FDA-approved, standardized test to detect silicone in the body . . . Researchers have developed a test that can detect antibodies to silicone in blood. However, even if such antibodies were detected, the significance would be unclear."³

A position paper of the College of American Pathologists states:

Current FDA status

At present, silicone gel-filled breast implants are only available to women who are enrolled in an FDA-approved, manufacturer-sponsored clinical trial. These clinical trials are only open to women with special medical needs, including women who have had breast cancer surgery, severe traumatic injury to the breast, a birth defect that affects the breast, or a medical condition causing "a severe breast abnormality." Women are also eligible if they have an existing silicone gel-filled implant that must be replaced for medical reasons (e.g., rupture). There are also plans for limited studies on implants provided for cosmetic reasons. In 1996, the FDA wrote a letter to implant manufacturers, listing their requirements for additional data and encouraging them to begin the study necessary to submission of a Premarket Approval Application.

In January 1993, manufacturers of saline-filled breast implants were notified that they, too, would be required to submit proof of the safety and effectiveness of their products to the FDA. While these studies are being conducted, however, saline devices have remained available for cosmetic and reconstructive use without restriction.

Recommendations

The following statements, recommended by the Council on Scientific Affairs, were adopted by the AMA House of Delegates as AMA policy at the 1996 AMA Interim Meeting.

1. Policy 525.983 (AMA Policy Compendium) is amended to read as follows:

The AMA:

(a) continues to support the establishment of a registry of all patients with breast implants, so that data pertaining to health outcomes can be regularly reviewed and reported to physicians and patients; (b) supports the position that women have the right to choose silicone gel-filled or saline-filled breast implants for both augmentation and reconstruction after being fully informed about the risks and benefits; (c) urges physicians be informed of the current scientific data available in order to recognize and address the considerable public anxiety concerning the safety of breast implants. Patients can be reassured that, to date, there is no conclusive or convincing evidence that relates silicone breast implants to human autoimmune disease; (d) supports appropriate data collection and follow-up in all cases in which such implants are utilized, and that clinical trials as proposed by the FDA do not limit the woman's right to choose;(e) will monitor the process of decision-making by the FDA on the use of not only silicone gel breast implants but also all silicone-based devices, with particular attention to use of expert medical judgment and to issues of conflict of interest; and (f) requests that specific FDA policies regarding the process of evaluation of devices be developed and publicized to the medical profession and the public, and that the process be sensitive to the emotional impact on the patient. 

2. The AMA condemns the inappropriate use of laboratory tests that purport to measure the  dissemination of silicone through a patient's body and which are used to make unsubstantiated diagnoses of silicone-related illness.

Note: This report was published in Plastic Surgery News (March 1997).

References

1. Lilienfeld DE, Stolley PD. Foundations of Epidemiology. New York City, Oxford University Press, 1994.
2. Brody GS. Safety and effectiveness of the silicone breast implant. American Society of Plastic and Reconstructive Surgeons, Inc. September 1996.
3. Food and Drug Administration. Breast Implants. An Information Update. Food and Drug Administration. March, 1996.
4. Deapen D, et al. Augmentation mammoplasty and breast cancer: a five year update of the Los Angeles study. Plastic and Reconstructive Surgery. 1992;89:660-665.
5. Ford NF, Gale PJ, Hammett JL, Raymond RH, Shostack GR. Final report on the pilot study of urine and serum samples from women with Meme and Replicon breast implants. Presented by Bristol-Myers Squibb Company to the U.S. Food and Drug Administration, July 14, 1995.
6. Carlson GW. The detection of breast cancer after augmentation. Plastic Surgical Forum. 1991;14:10-11.
7. Gabriel SE, O Fallon WM, Kurland LT, Beard CM, Woods JE, Mellon LJ. Risk of connective tissue diseases and other disorders after breast implantation. NEJM. 1994;330:1697-1702.
8. Englert HJ, Brooks P. Scleroderma and augmentation mammoplasty--a causal relationship? Aust NZ J Me. 1994;24:74-80.
9. Sanchez-Guerrero J, Colditz GA, Karlson EW, Hunder DJ, Speizer FE, Liang MH. Silicone breast implants and the risk of connective-tissue diseases and symptoms. NEJM. 1995;322:1666-1670
10. Hennekens CH, Lee I-M, Cook NR, Hebert PR, Karlson EW, LaMotte F, Manson JE, Buring JE. Self-reported breast implants and connective-tissue diseases in female health professionals. JAMA. 1996;275:616-621.
11. Levine JJ, Ilowite T. Scleroderma esophageal diseases in children breast-fed by mothers with silicone breast implants. JAMA 1994;271:213-216.
12. Levine JJ, et al. Lack of autoantibody expression in children born to mothers with silicone breast implants. Pediatrics. 1996:97:243-245.
    

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