Summary of Studies of Saline and Connective Tissue Diseases

February 2000
By Diana Zuckerman, Ph.D

The following is a list of the major epidemiological studies that have evaluated the safety of breast implants pertaining to connective tissue diseases. The studies fall into two major categories; cohort studies and case-control studies. Cohort studies compare women who have received breast implants to those who have not and compare the incidence of illness in the two groups. Case-control studies compare women suffering from a particular disease to those who are healthy and determine whether breast implants are more common in the ill women.

These studies have been cited by the Institute of Medicine, Judge Pointer’s scientific panel, Marcia Angell, and others as evidence that breast implants are safe, even though they have a number of very serious shortcomings. In addition, these studies provide very little information about saline breast implants. Some of the limitations are listed below:

The studies don’t measure most health risks. They only study connective tissue disease, not other problems such as pain, hardening, fibromyalgia, or cancer.

Many of the studies do not include any women with saline breast implants. Others include a few women with saline implants. The studies that do include women who have received saline implants often do not analyze them separately from those that have silicone implants. As a result, it is impossible to draw conclusions about the safety of saline implants.

Many of the studies do not include any women (or only very few women) who received implants after mastectomy. That group of women probably faces different risks because of impaired immune systems and lack of breast tissue.

Sample sizes in most of the studies are too small to reveal a connection between breast implants and diseases that occur at a very low rate in the general population. Since many of the diseases studied are rare, such as scleroderma, it is impossible to conclude whether or not implants can cause these diseases.

Most of the studies include many women with implants for a few months or years. Since most of the diseases studied take many years to develop and be diagnosed (such as scleroderma), it is impossible to determine the long-term safety of implants from these studies.

Cohort Studies

Edworthy et al., 1998
Design: Cohort study of breast implant recipients.
Does study include saline implants? YES
If so, how many? 352 of 1576
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Friis et al., 1997
Design: Cohort study of breast implant recipients.
Does study include saline implants? unclear
If so, how many? 16% had unspecified types of implants
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Gabriel et al., 1994, “Mayo Clinic Study”
Design: Cohort study of breast implant recipients.
Does study include saline implants? YES
If so, how many? 95 (5.2%)
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Giltay et al., 1994
Design: Cohort study of breast implant recipients.
NO saline implants.

Hennekens et al., 1996, “Harvard Women’s Health Cohort Study”
Design: Cohort study of breast implant recipients.
Does study include saline implants? Probably
If so, how many? unknown
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Nyren et al., 1998
Design: Cohort study of breast implant recipients.
Does study include saline implants? YES
If so, how many? 24% of a random cohort within the study
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Park et al., 1998
Design: Cohort study of breast implant recipients.
NO saline implants.

Sanchez-Guerrero et al., 1995, “Harvard Nurses’ Study”
Design: Cohort study of breast implant recipients.
Does study include saline implants? YES
If so, how many? 170 of 1183
Were saline implants analyzed separately? YES
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Schusterman et al., 1993
Design: Cohort study of all breast cancer patients who had reconstruction.
NO saline implants.

Weisman et al., 1988
Design: Cohort study of cosmetic breast implant recipients.
NO saline implants.

Wells et al., 1994
Design: Cohort study of cosmetic breast implant recipients.
NO saline implants.

Case-Control Studies

Burns et al., 1996
Design: Case-control study of women with scleroderma.
Does study include saline implants? Only two subjects had implants – one had saline (both were controls without scleroderma).
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Goldman et al., 1995
Design: Case-control study of women with rheumatoid arthritis and connective tissue disease.
Does study include saline implants? YES
How many: 4% saline, 11% unspecified.
Were saline implants analyzed separately? NO
Does the study specifically analyze breast cancer patients receiving saline implants? NO

Hochberg et al., 1996
Design: Case-control study of women with scleroderma.
NO saline implants.

Strom et al., 1994
Design: Case-control study of women with lupus.
NO saline implants.

Williams et al., 1997
Design: Case-control study of women with connective tissue disease.
NO saline implants.