What is Silicone? - From Inamed

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What is Silicone? H A T I I L I C O N E

CAUTION: Silicone-Filled breast implants are limited

distribution devices, and are only available by or on

the order of a licensed physician as part of a McGhan

Medical Clinical Study.

The purpose of this brochure is to provide answers to

some of your questions about silicones and breast

implants, and to provide an overview of silicones,

their common uses, and why they are chosen by medical

professionals. The reference numbers throughout the

text indicate the sources of information discussed in

this brochure.

Please refer to the " Reference " section for more

information. As with any medical device or drug, the

risk of possible adverse effects must always be

weighed against the ability to provide benefits. If

you have any questions, please be sure to ask your

physician. Please note, this brochure is not meant to

supplement or replace product labeling or medical

advice regarding risks and benefits associated with

implantable devices.

INTRODUCTION WHAT IS SILICONE?

Silicones are a family of chemical compounds. They are

made from silicon, a naturally occurring element found

in sand, quartz, and rock. Next to oxygen, silicon is

the most common element in the earth's crust, and

becomes silicone when it is combined with oxygen,

carbon, and hydrogen. Depending on the arrangement of

the molecules, silicones can be manufactured in a

variety of forms, including oils, gels, and solids.1

CONSUMER AND MEDICAL PRODUCTS

Silicones have been part of the consumer industry for

over 50 years. Because they can be manufactured in

various ways, silicones appear in a wide variety of

products that most of us use everyday. Hairsprays,

suntan lotions, and moisturizing creams are just some

of the consumer products that contain one form of

silicone called dimethicone. The applications of

silicone, whether used as an oil, gel, or solid, are

equally extensive in the medical field. For example,

the lubricating qualities of silicones make them ideal

for coating surgical needles and suture thread, as

well as the inside of syringes and bottles used for

the storage of blood and intravenous medicines.

Protective silicone coatings have also been used in

pacemakers and heart valves. Other medical devices

utilizing silicones include: artificial joints,

catheters, drainage systems, facial implants, tissue

expanders, and breast implants. Silicone products have

been shown to be biocompatible, reliable, flexible,

and easy to sterilize, making them an ideal choice for

both implantable and non-implantable medical devices.

SAFETY ISSUES

Safety issues concerning the use of silicone in

medical devices have primarily focused on the possible

link between breast implants (both saline-filled and

gel-filled) and certain illnesses, including breast

cancer and connective tissue disorders (also referred

to as autoimmune diseases such as lupus, scleroderma,

and rheumatoid arthritis).

Silicone materials have been tested extensively in

laboratory studies, as well as clinical studies (those

that study human health). Of the one to two million

women who have received breast implants, much

scientific evidence has already been gathered. The

following is a summary of current published scientific

information concerning silicone breast implants,

breast cancer, and connective tissue disorders (CTDs).

SILICONE BREAST IMPLANTS AND BREAST CANCER

Breast cancer occurs in tissues dense with ducts and

glands, and may spread throughout the body. About one

in every eight women in North America develops breast

cancer in her lifetime.2 Because of the safety issues

surrounding silicone in medical devices and the

incidence rate of breast cancer in the human

population, questions concerning increased risks of

developing breast cancer for women with breast

implants have been raised. As the following clinical

studies indicate, the likelihood of developing breast

cancer does not seem to increase with the use of

silicone breast implants.

A 1986 University of Southern California study

published in Plastic and Reconstructive Surgery

investigated over 3,000 women in the Los Angeles area

who received silicone breast implants between 1959 and

1980. Results found no increased risk of breast

cancer following breast implant surgery compared to

standard incidence ratios.3 A 1992 five year update of

this study followed the same group and confirmed the

original findings.4

A 1992 University of Calgary study published in the

New England Journal of Medicine investigated over

11,000 women in Alberta, Canada who received silicone

breast implants between 1973 and 1986. This study,

" did not find an increased risk of cancer among women

who had received breast implants, although the length

of follow-up, the completeness of follow-up, and the

size of the cohort would have allowed the detection of

such a risk. " 5

A 1996 Georgia, New Jersey, and Washington study

published in Plastic and Reconstructive Surgery,

investigated over 2,000 women with breast implants.

The results of this study are consistent with those of

the Los Angeles and Alberta studies, finding no

association between silicone breast implants and

breast cancer.6

A 2000 brochure published by the Institute of

Medicine, Information for Women About the Safety of

Silicone Breast Implants reports " Evidence clearly

shows that silicone breast implants do not cause

breast cancer or the recurrence of breast cancer. In

fact, some studies suggest that women with breast

implants have fewer new or recurring cancers. " 14

SILICONE BREAST IMPLANTS AND BREAST CANCER DETECTION

Most studies using standard mammography have shown no

difference in the average time to detect breast cancer

between women with and without breast implants, nor

have they shown a difference in the stage of disease

detected. However, because implants may interfere with

standard mammography by obscuring some underlying

tissue and/or by compressing overlying tissue, you

should inform your radiologist about your implants and

request diagnostic mammography. Specifically, your

radiologist should be experienced with current

mammographic displacement techniques (such as the

Eklund technique) for imaging the breast tissue around

the implants and should provide you with multiple

mammographic views. Diagnostic mammography may

facilitate early diagnosis of small masses that may be

difficult to see with standard mammography.3

SILICONE BREAST IMPLANTS AND CONNECTIVE TISSUE

DISORDERS

Connective tissue disorders (CTDs) are described as a

group of generalized disorders affecting the

connective tissues (i.e., fat, bone, and mucous). It

has been theorized that silicone breast implants may

increase the risk of developing a CTD. As the

following clinical studies indicate, actual

statistical information has provided no significant

evidence that silicone breast implants greatly

increase the risk of developing CTDs.

A 1993 University of Texas, Houston study published in

the ls of Plastic Surgery investigated 603 women

undergoing reconstructive breast surgery between 1986

and 1992. In this study 250 women had breast

reconstruction with silicone gel-filled breast

implants and 353 women had breast reconstruction

utilizing their own tissue. Results of this

preliminary report found that " the incidence of

autoimmune diseases in mastectomy patients receiving

silicone gel implants is not different than in

patients who had reconstruction with autogenous

[patient's own] tissue. " 7

A 1994 Mayo Clinic study published in the New England

Journal of Medicine compared 749 women who had breast

implant surgery between 1964 and 1991, with 1,498

women who did not have breast implantsurgery. Study

results showed " no association between breast implants

and the connective tissue diseases and other disorders

that were studied. " 8

A 1995 Harvard/Brigham's Hospital study published in

the New England Journal of Medicine analyzed 14 years

of follow-up data from the Nurses Health Study Cohort.

This resulted in the review of over 87,000 women, with

and without breast implants. Results found no

" association between silicone breast implants and

connective tissue diseases. " 9

A 1994 ish study published in Plastic and

Reconstructive Surgery compared 317 women with

silicone-filled breast implants over a 10 period with

women who did not have breast implants. The average

follow-up time was 68 months. This study concluded,

" no differences were found in the symptoms or physical

signs of connective tissue diseases between the study

patients and their controls. This study has failed to

find any case for a link between silicone gel-filled

breast implants and connective tissue diseases. " 10

A 1996 Canadian study published in The Journal of

Rheumatology was a retrospective study in Alberta that

recruited 1,576 women including 1,112 who had received

silicone breast implants between 1978 to 10 1986.

Post-surgical diagnoses of the principal targeted

conditions of rheumatoid arthritis, systemic lupus

erythematosus, scleroderma and

Sjögren's syndrome did not indicate an increased

incidence of typical or atypical CTD. " The results of

this study do not support the hypothesis that silicone

gel-filled implants induce or promote CTD. " 11

A 2000 brochure published by the Institute of

Medicine, Information for Women About the Safety of

Silicone Breast Implants states " there is no evidence

that silicone breast implants contribute to an

increase in autoimmune (connective tissue) diseases. A

review of 17 separate studies of the occurrence of

connective tissue disease in the population was

remarkable for the consistent finding of no elevated

risk or no indication of an association of implants

with disease. Evidence suggests that such diseases are

no more common in women with breast implants than in

women without them. " 14

A published statement prepared by the American College

of Rheumatology

(ACR) - a task force of plastic surgeons,

rheumatologist specialists, and the American Medical

Association - advises that while a theoretical risk

for CTDs might exist, especially for a patient with a

CTD, there is " no reason to discourage women from

considering breast [implant surgery] on the basis of

acquiring or exacerbating a connective tissue

disorder. " 12

TESTING FOR SILICONE IN THE BODY

Recently researchers have developed tests to detect

silicone in the body. These tests have become a factor

regarding the safety issues of silicone breast

implants and the human body & #8217;s response to the

silicone found in these products. The FDA, at this

time, has not approved any of these detection tests,

and has indicated that the results of these tests

should be viewed cautiously. Further, the FDA has

indicated that " determining silicone is present in

body fluids does not indicate whether a person is

sensitive to these substances or at risk for any

specific disease...[and] the significance [of silicone

detection] would be unclear. " 13

CONCLUSION

A number of clinical studies have indicated that there

is no conclusive scientific evidence that silicone

materials in breast implants greatly increase the risk

of developing breast cancer or CTDs. We hope this

brochure has given you a better understanding of the

issues surrounding silicones, especially silicone

breast implants.

If you have any further questions about silicones and

breast implants, ask your physician about the

following brochures: " Breast Implant Information

Package " provided by the FDA (1-888-INFO-FDA). " Making

an Informed Decision: Saline-Filled Breast Implant

Surgery - provided by INAMED Aesthetics

(800-624-4261). " Breast Augmentation: A Woman's

Choice " provided by INAMED Aesthetics

(800-624-4261). " Choices in Breast Reconstruction: A

Guide to Breast Implants and Surgical Options "

provided by INAMED Aesthetics (800-624-4261).