Amended Report 03/24/2005

Breast Implants: 

Status of Research at the National Institutes of Health (NIH)

Introduction 

In compliance with Section 215(a) of the Medical Device User Fee and 

Modernization Act of 2002 (P.L. 107-250), the NIH has prepared the following 

report to Congress describing the status of research on breast implants being 

conducted or supported by the agency.

Breast implants were first marketed in the early 1960s, before the 1976 Medical 

Device Amendments to the Food, Drug and Cosmetic Act required medical 

devices be shown to be safe and effective. Since 1962, an estimated 1.5 million 

to 2.5 million U.S. women have had breast implant surgery. Although implants 

were originally assumed to be biologically inactive and therefore safe, numerous 

concerns have arisen regarding possible biologic effects. Most of the concern

regarding long-term risks has focused on connective tissue disorders given a 

number of anectodal reports of these diseases being diagnosed among women 

with breast implants. In addition, there has been some concern expressed 

regarding possible effects on cancer risk, particularly breast cancer and cancers 

associated with immunologic disturbances. In 1992, the U.S. Food and Drug 

Administration decided to limit the availability of the implants to women who were 

undergoing breast reconstruction in controlled clinical trials, until the long-term 

safety of the implants for all women could be established. In addition, Congress 

charged NIH with conducting a follow-up study to examine the health effects of 

the implants. 

Background 

About 80 percent of breast implants in the United States are for cosmetic 

reasons and 20 percent for breast reconstruction after breast cancer surgery. 

The majority of previous studies have focused on women who received implants 

for cosmetic reasons. 

1. Breast Cancer Risk

A number of previous studies have evaluated the relationship between 

breast implants and subsequent breast cancer risk. Most have shown that 

the risk of developing breast cancer is less among women with implants 

compared to women without implants. In several of the studies, the size of 

the reduced risk was as much as 50 percent to 60 percent. However, the 

vast majority of studies did not have enough detailed information on 

patient characteristics that could affect the development of breast cancer, 

and had follow-up times of less than 10 years. The most recent studies, 

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which have been considerably larger than previous studies and have been 

able to assess long-term risks, do not support the notion that implants are 

related to breast cancer risk. 

2. Stage at Diagnosis of Breast Cancer

Some clinical studies have suggested women with breast implants have 

more advanced breast cancer at diagnosis than women without breast 

implants. This is because implants have been shown to interfere with the 

ability to detect breast lesions by mammography. However, several 

recent epidemiologic studies which compared the stage of disease at 

breast cancer diagnosis among women with breast implants with other 

women found no significant differences. 

3. Mortality 

Most of the attention regarding mortality of breast implant patients has 

focused on breast cancer mortality. These studies have generally shown 

no differences in breast cancer mortality for breast implant patients as 

compared with the general population. More recent studies have 

evaluated other causes of death. Several studies have noted an 

increased risk of suicide among breast implant patients. No other causes 

of death have been consistently linked with breast implants.

4. Types of Implant 

Because earlier reports did not include detailed information about the 

types of implants, an evaluation of the effect of the implant type on the 

health risks of the patients has not been possible. 

5. Connective Tissue Disorders

Anecdotal reports have suggested increased risks of certain connective 

tissue disorders, including scleroderma, systemic lupus erythematosus, 

rheumatoid arthritis, and Sjogren's syndrome. Attempts have been made 

in a number of epidemiologic studies to assess these relationships. 

However, given that these are all rare diseases, it has been difficult to 

draw conclusions regarding whether there are any alterations in risk 

among breast implant patients. A large meta-analysis that followed an 

Institute of Medicine review of the literature concluded that there was not 

sufficient evidence to support any relationships with these disorders. 

A recent NCI study emphasized the complexities of evaluating the effects 

of breast implants on the risk of developing connective tissue disorders 

(CTDs). Elevated risks associated with self reports of these conditions 

became statistically insignificant after attempts were made to confirm the 

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diagnoses through record retrieval and review by board-certified 

rheumatologists. Further research, including record linkage efforts, 

utilization of standardized diagnostic criteria for connective tissue 

disorders, and standardized clinical exams among women with implants, 

would be needed to understand if a relationship exists between CTDs and 

breast implants. 

6. Women who Receive Implants for Breast Reconstructive Surgery 

One small study reported no increase in the development of second 

primary breast cancer in women with silicone implants following 

mastectomy compared to women who received mastectomies without 

implants. The small size of the study, however, limits the conclusions. A 

large study reported in 2004 that women receiving implants after 

mastectomies for early-stage breast cancer experienced lower breast 

cancer mortality than women not receiving implants. Assessment of 

survival among these patients is complex, given unique patient 

characteristics, disease attributes, and treatment patterns. Interpretation 

of reduced mortality from breast cancer must be assessed in light of 

significantly reduced risks of death from most other causes, and the 

contrasting elevated rates of suicide, which are consistent with findings 

among women with cosmetic implants. 

Note: Any study of the risks of breast cancer or other cancers with women 

who receive reconstructive implants is more complicated than one 

involving women with cosmetic implants because it needs to take into 

account the effects of different breast cancer treatments. A study with 

breast cancer patients would best be done in the context of a clinical trial 

where comparisons can be made between women who choose to have 

reconstruction and those who do not, but who otherwise have received 

identical treatments. 

Current NIH Studies – National Cancer Institute (NCI) 

1. Follow-up of Women with Augmentation Mammoplasty

Project Funding Period: October 1, 1992 to present 

Project ID: Z01- CP10128 Study #42-92-00

Overview

FY1992 Senate Appropriations Report (102-104) asked NCI to develop a 

strategy for conducting longitudinal studies of women with various types of 

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silicone breast implants. In 1993, the NCI’s intramural Division of Cancer 

Etiology (now the Division of Cancer Epidemiology and Genetics) initiated a 

retrospective cohort study, to assess the long-term health effects of silicone 

breast implants. 

This is one of the longest and largest studies to date on the health effects of 

breast implants. Most previous investigations have looked at the effects of 

implants over a shorter time period, typically less than 10 years. Besides the 

short follow-up periods, previous studies have been too small to evaluate rare 

diseases. In addition, previous reports have not included information about types 

of devices implanted or risk factors affecting health, such as medical history, 

screening practices, and lifestyle behaviors. All of these factors are included in 

the current NCI study. 

Another unique feature of this study is that the investigators compared the breast 

cancer risks of the implant patients to both the general population and other 

plastic surgery patients. Previous studies have generally used only the general 

population for a comparison group, except for a recent Swedish study that 

compared women with implants to those with breast reduction procedures. 

Analyses of cancer risk and overall mortality in this study have been completed 

and published (See Appendix A). Analyses of the risk of connective tissue 

diseases related to breast implants are underway. 

Participants of the Study

The participants include 13,500 women who had implant surgery for cosmetic 

reasons in both breasts before 1989. For comparison, about 4,000 women 

similar in age who had some other type of plastic surgery, such as removal of fat 

from the abdomen or wrinkles from the face or neck, were identified. All 

participants were from 18 plastic surgery practices in six geographic areas 

(Atlanta, GA.; Birmingham, AL.; Charlotte, N.C.; Miami and Orlando, FL.; and 

Washington, D.C.). The practices were chosen because the plastic surgeons had 

performed large numbers of cosmetic breast implant surgeries prior to 1989 and 

were willing to give the investigators access to their records. 

Study Design 

The medical records from the plastic surgery practices were reviewed to identify 

patients who were eligible for the study. For eligible patients, trained medical 

records abstractors collected information about the surgical procedures, the type 

of implant, any complications, and factors which might affect health status, such 

as weight or medical history. 

Patients were then traced through a variety of sources. Living subjects were 

asked to complete a mailed questionnaire to collect information about their health 

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status, including whether they had subsequent plastic surgery as well as lifestyle 

factors that could affect their health (menstrual, pregnancy, and breast-feeding 

history, weight, hormone use, cigarette smoking, alcohol consumption, and 

medical history). Extensive data on the potential short-term (rupture) and longerterm complications (cancer, connective tissue diseases, symptoms of connective 

tissue disease) were also obtained through the questionnaire. 

No clinical examinations were done on the living patients for this study. Attempts 

were made to verify patient reports of cancer and connective tissue diseases by 

retrieving medical records from physicians who had diagnosed or treated these 

diseases. Death certificates were collected for the patients who had died to verify 

the causes of death. 

About 80 percent of the original 13,500 implant patients and 4,000 controls were 

successfully traced. About 70 percent of those traced as alive completed the 

questionnaires. These percentages are similar to other comparably designed 

epidemiological studies. 

Results 

• NCI researchers found no significant increase in breast cancer incidence 

or mortality among women with implants compared to controls. In fact, a 

slight decrease in breast cancer risk was found during the initial 10-year 

follow-up period, perhaps due to medical screening prior to implant 

surgery. 

• Patients in the study group experienced lower rates for nearly every 

cancer and for total mortality when compared to the general population, 

except for an elevation in mortality from brain cancer and suicide. When 

compared to other plastic surgery patients, implant patients had a slightly 

higher incidence of cancer, driven primarily by excess risks for brain and 

lung cancers. Considering the mortality and cancer incidence analyses, 

and comparison both with the general population and with other plastic 

surgery patients, excess risks of suicide and cancers of the lung and brain 

appear to warrant further scrutiny. While the reasons for these excesses 

are unclear, it is possible that the higher risks observed are due either to 

chance or to factors common to women who choose to have implants, 

such as smoking in relation to the lung cancer excesses. 

• Researchers at the NCI found no convincing evidence that breast implants 

have an effect on the development of subsequent connective tissue 

disorders (CTDs). While a large number of patients reported CTDs, when 

their records were examined by two board-certified rheumatologists, few 

cases of the major CTDS (rheumatoid arthritis, systemic lupus 

erythematosus, scleroderma, and Sjogren’s syndrome) were considered 

likely. Further, the small number of confirmed cases of scleroderm and 

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Sjogren’s syndrome made interpretations of the risks difficult. Given the 

rarity of these two conditions, a study would need to be very large to fully 

clarify an association. 

• The lower overall mortality rates of the implant population support

previous findings that people who undergo elective surgery are generally 

healthier than their peers.

Future Plans 

NCI researchers plan to continue to follow the cohort to update the mortality data 

over time, which may shed light on the observed excess risks of lung and brain 

cancers, and of suicide. The FDA has studied some of the women in the NCI’s 

study population for implant ruptures. 

2. Prophylactic Mastectomy in Hereditary Breast Cancer

Project Funding Period: September 30, 1999 to July 2003

Project ID: R01, CA80181 

In a study designed to evaluate the efficacy of prophylactic mastectomy (PM) in 

preventing breast cancer among high-risk women, investigators at the Mayo 

Clinic in Rochester, MN are collecting and analyzing data from women with 

hereditary breast cancer risk who have elected to undergo PM. The Mayo Clinic 

has served as a referral center for specialized surgeries, including PM, for many 

years. The investigators have access to two groups of high-risk women who 

elected PM: unaffected women who have elected PM and women treated for 

their first breast cancer who elected contralateral PM. For the study, the sisters of 

women electing PM serve as a reference group. 

Although the primary focus of the study is to clarify the magnitude of breast 

cancer risk reduction for high-risk women who undergo PM, the investigators 

have also collected clinical information on reconstructive surgery, breast 

implants, and complications. The additional data about reconstructive surgery 

and implant use collected by the researchers may provide information about 

long-term outcomes and effects of implant use in this highly selected group of 

women. 

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Current NIH Studies – National Institute of Biomedical Imaging and 

Bioengineering 

1. A Convertible PET Camera for Oncology

Project Funding Period: July 1, 1993- August 31, 2003 

Project ID: RO1, EB000217 

Researchers at the University of Texas are evaluating a positron emission 

tomography (PET) prototype scanner designed to improve the performance and 

lower the cost of PET for clinical and research applications. One of the proposed 

clinical applications is improved diagnosis of breast cancer in women with 

implants. Traditional x-ray mammography is not as useful in women with breast 

implants because the implant shows up on the x-ray as a dense shadow which 

may hide cancerous tumors. Alternatively, PET imaging could improve images 

that highlight cancerous breast tumors, particularly in women with implants. In 

addition, the prototype PET scanner may reduce unnecessary biopsy for women 

with false-positive mammograms. The PET scanner prototype has convertible 

modes of operation: (1) A high sensitivity brain and animal mode, (2) a wholebody tumor localization mode and (3) a breast mode with 8 times the sensitivity 

of standard PET scanners. The high-resolution, high-sensitivity brain mode 

would be useful for detecting small lesions, for a more sensitive differentiation of 

recurring tumors from necrosis, and for studies of small structures in the brain. 

The whole-body mode would be useful for tumor localization, cancer staging, and 

cardiac functional studies. The breast mode, with 8 times the detection 

sensitivity, can improve the specificity and sensitivity of breast cancer diagnosis. 

It is also useful for diagnosing small or early breast tumors, especially in younger, 

high-risk women and women with breast implants, which present difficulties for xray mammography. 

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Current NIH Studies – National Institute of Environmental Health Sciences

(NIEHS) 

NIEHS continued support for a project that was initiated in the Food & Drug 

Administration. This project has been overseen by the FDA Research in Human 

Subjects Committee and was assigned the FDA designation of Center for 

Biologics Evaluation and Research protocol #119. The title of the protocol is 

"EPIDEMIOLOGIC, IMMUNOLOGIC AND IMMUNOGENETIC FACTORS IN 

SILICONE-ASSOCIATED CONNECTIVE TISSUE DISEASES". This is a case 

control evaluation of the signs, symptoms, serology and genetic risk factors 

associated with the development of myositis in women who have had silicone 

implants or injections. The investigators have enrolled a total of 231 subjects into 

this protocol. The study, now complete, showed the following result: Women in 

whom inflammatory myopathy develops after they receive silicone implants 

constitute an immunogenetically distinct group of patients with myositis. These 

and other data suggest that autoimmune diseases as now defined may consist of 

multiple distinct entities, each of which is characterized by different genes and 

environmental exposures. 

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APPENDIX A 

Publications 

Brinton LA, Brown LS, Colton T, Burich MC, Lubin J. Mortality among 

Augmentation Mammoplasty Patients. Epidemiology May 2001; 12 (3): 321. 

Brinton LA, Brown LS, Colton T, Burich MC, Lubin J, Hoover RN. Cancer Risk at 

Sites Other than the Breast Following Augmentation Mammoplasty. Annals of 

Epidemiology May 2001; 11 (4): 248-256. 

Brinton LA, Brown LS, Colton T, Burich MC, Lubin J, Hoover RN. Breast Cancer 

Following Augmentation Mammoplasty (United States). Cancer Causes and 

Control 2000; Vol. 11(9): 819-827. 

Brinton LA, Brown LS, Colton T, Burich MC, Lubin J. Characteristics of a 

Population of Women with Breast Implants Compared with Women Seeking 

Other Types of Plastic Surgery. Plastic and Reconstructive Surgery 2000; 105(3): 

919-27. 

Brinton LA, Buckley LM, Dvorkina O, Jay H. Lubin, Theodore Colton, 

Mary Cay Murray, and Robert N. Hoover. Risk of Connective Tissue Disorders 

among Breast Implant Patients. American Journal of Epidemiology 

Copyright 2004; 60 (7): 620-627. 

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