WASHINGTON -- Scientists within Dow Corning Co. urged company officials for years to conduct critical safety studies of its silicone gel breast implants, but the tests were put off for more than a decade, a review of hundreds of company documents shows.
The documents, made available to the New York Times from several sources, also suggest that the studies that were done were inadequate. They describe insertion of implants into women before they had been tested in animals and suggest that Dow Corning Wright breast implants might have been tested in animals but not in animal breast tissue.
In 1976, 16 months after a new type of implant was first put into women, an official in charge of its development was still expressing frustration over the lack of data about it.
"We are engulfed in unqualified speculation," wrote A. H. Rathjen, chairman of a task force working on the new implant at Dow Corning. "Nothing to date is truly quantitative. Is there something in the implant that migrates out or off the mammary prosthesis? Yes or no! Does it continue for the life of the implant or is it limited or controlled for a period of time? What is it?"
Officials of Dow Corning maintain that the implants are safe, that most women who have them are delighted with them and that the memorandums among the company documents challenging company practices paint an inaccurate and incomplete picture. Critics challenge that view.
"Dow Corning and the plastic surgeons have conducted a massive experiment on women, under the guise of selling a commercial product," said Thomas Talcott, a private consultant in California who quit Dow Corning in 1976 in what he said was a protest of its safety practices. Mr. Talcott, an engineer, was the head of the company's technical services and development group, which was responsible for testing the implant components.
The Food and Drug Administration called for a moratorium on the devices last week pending a review of safety data.
An agency panel will meet Feb. 11 to consider the matter.
"We cannot assure the safety of this product," FDA Commissioner David A. Kessler said in announcing the moratorium.
To Dr. Norman Anderson of the Johns Hopkins University, who hasbeen a consultant to the FDA on the issue, the lack of directly relevant scientific studies is astonishing.
In a letter he sent to Dr. Kessler three days ago, he noted that he had reviewed all 10,000 pages of Dow Corning's submissions to the FDA and found that none of the studies in animals put silicone or implants in or under breast tissue, as is done with women.
"Although I am only a clinician, I find this omission a peculiar phenomenon which must be unprecedented in the history of medical device evaluation," the letter said.
But the current chief of the health care business at Dow Corning, Robert T. Rylee, said the implants have been adequately tested and shown to be safe. He said the memorandums reflected disagreements within the company and said other documents might counter their assertions.
Mr. Rylee said of the memorandums, "This is a normal part of business activity, people voicing their opinions, to help guide and direct the company. Questions will be asked."
He said the questions were also answered ultimately.
The company says it is willing to carry out large, long-term studies to answer more questions but insists that the implants should remain on the market in the meantime.
The company acknowledges in its warning labels that formation of stiff scar tissue, known as capsular contracture, can be a side effect of the implants, but officials say problems with them are far less common than critics contend.
Dow Corning Wright, a joint venture of Dow Chemical Co. and Corning Inc., is the largest maker of breast implants and has dominated the market from the earliest days of their manufacture. It has done more testing than any other maker, the FDA, the company and its competitors say.
No one knows exactly how many American women have received implants; estimates range from 1 million to 2 million. About 20 percent of the implants are for reconstruction after cancer surgery. The rest are used to enlarge the breasts for cosmetic purposes.
Company officials in the 1960s were dazzled by silicone for implants, which seemed inert, did not react to acids or akalines and were flexible as a noodle. When plastic surgeons saw and felt the material, "their eyes got big as saucers," Mr. Talcott said.
"It was not that the people in the company were greedy and callous," he recalled. "They believed these things were safe."
It was not until 1988 that the federal government asked for rigorous safety data on implants. And meanwhile most women were delighted with their implants.
Nevertheless, safety questions were raised again and again.
A report dated Feb. 7, 1975, describes studies on rabbits showing "mild to occasionally moderate acute inflammatory reaction" that might be explained by the surgery itself on the rabbits, rather than leaks of silicone.
But even before these results were in, eight women in Vancouver had already received them in what the company described as a "clinical experiment."
The company says the women were informed that the devices were experimental.
In 1976, Mr. Rathjen received a series of complaints from doctors who had seen severe inflammatory reactions in women, as well as silicone migrating in women's bodies.
In 1987, 12 years after the new gel implants had been put in women, Dr. Robert R. Levier, technical director of Dow Corning's health care businesses, recommended tests "be designed and conducted to resolve such issues as in vivo material transport, local reaction, characteristics, and systemic effects."
The FDA finally demanded that Dow Corning produce all its best evidence that silicone gel breast implants are safe by last July.