ONE OF THE longest-running and most expensive taxpayer-funded projects at the National Cancer Institute in Bethesda, Maryland, has nothing to do with curing cancer.

Since the Bush administration, an epidemiologist named Louise Brinton has been quietly at work on a study of a product that dozens of scientific institutions from Harvard to the Mayo Clinic have confirmed does not cause illness -- the silicone breast implant.

Brinton, who is chief of the environmental epidemiology branch of the National Cancer Institute, has adopted an unorthodox approach that is raising scientific eyebrows. Although her study of the long-term health effects of silicone implants won't appear until later this fall, the concerns of her peers seem justified. Documents obtained through the Freedom of Information Act confirm that in drawing up procedures for her $ 4 million project and in recruiting some 13,500 women participants, Brinton collaborated with anti-implant activists, including plaintiffs' lawyers and their paid expert witnesses.

Of course, contact between a scientist and parties with a vested interest in the outcome of a study doesn't automatically slant the result. But the extensive nature of Brinton's associations is curious and ethically questionable, especially since Brinton, who refused several times to be interviewed for this story, is a government official.

One plaintiffs' lawyer with whom Brinton has been in contact is LeRoy Hersh of San Francisco, a member of the Plaintiffs' Steering Committee of top lawyers handling implant litigation. Hersh's firm won a $ 1.7 million settlement against Dow Corning in 1985 in one of the first significant breast implant cases. Since then, Hersh has been hoping new scientific findings would vindicate him and his approximately 400 implant clients. In 1995, Brinton agreed to be a consultant for Hersh, and he wrote to her about the medical condition of at least one of his clients. In one letter, he asked her about a possible "relationship" between implants and cancer. Now, Hersh says Brinton's forthcoming study represents a "chance to come up with a conclusion which we haven't heretofore had."

Brinton has had even more contact with Stephen Sheller, a tort lawyer in Philadelphia. He arranged for her to appear before two dozen of the most prominent plaintiffs' lawyers in the country in July 1995 at the Manhattan law firm of Weitz & Luxemberg. Brinton made a presentation and disseminated material about her government work. She later described the session as an opportunity to "consult w/ plaintiff lawyers and silicone victims." Her expense report shows that her travel was paid for by the government.

Brinton wrote to Sheller about the July meeting that it had been productive "for us to share ideas" about "how valid data on long-term effects of breast implants could be obtained." Brinton agreed with the attorney that earlier studies were inadequate and thanked him for help in "acquiring the data" needed to "address the full spectrum of diseases possibly associated" with implants. Brinton spent another weekend as a guest of the trial lawyers, in November 1995, this time in Miami, again traveling at government expense. Sheller told Brinton that he and the other lawyers would encourage their clients to cooperate with her study, adding, "I would appreciate your coordinating with me whatever you need us to do to see that a complete, unbiased, effective study is done." One thing is certain: What a plaintiffs' lawyer would consider an "unbiased, effective study" would surely run counter to the scientific findings of the past ten years.

Brinton's involvement with the attorneys extended to permitting them a significant role in shaping the 28-page research questionnaire she sent to the subjects of her study. When she showed them an early draft, the advocacy groups weren't "happy with the questionnaire," Sheller told Brinton. She ought to be more definite about her goal. So Brinton tried to rally the troops: "The study provides an opportunity for women who may be suffering as a result of implants to be heard. Now is your chance," she wrote in a two-page informational document printed on the Department of Health and Human Services letterhead.

For Kenneth Shine, president of the Institute of Medicine at the National Academy of Sciences, such language signifies an effort to "encourage women with symptoms and problems to enroll" in the study. He told Science magazine he believes Brinton should have assiduously sought out a sample that included women who were happy with their implants as well as those who weren't.

In addition to attorneys, Brinton has worked with anti-implant activists. She sent a copy of her scientific protocol to the president of American Silicone Implant Survivors, Inc., and asked for "any support [she] could provide" as well as advice on how best to recruit "implant survivors." In the spirit of their feminist assumptions, Brinton's questionnaire asks subjects whether husbands and boyfriends pressured them to have surgery. All in the line of cancer research.

An Internet Web site called God's Silicone Angels (fantasyrealm.net/honeyb/SiliconeAngels), which memorializes women who have allegedly died because of their implants, quotes longtime Naderite Dr. Sidney Wolfe touting Brinton's work as "designed to correct the deficiencies" of previous studies -- studies Brinton herself has characterized as corrupted by "special interest monies." And in a conference call with activists on August 15, 1995, Brinton showed her partisanship, describing other studies as "bad science." "We need your help in telling women," she said, "that this one is valid."

Dr. Marcia Angell, editor of the New England Journal of Medicine and the author of a book on the breast implant controversy, says that since Brinton has the imprimatur of the National Cancer Institute (where a "multidisciplinary" panel of "national experts" and "consumer representatives" advises her and oversees her work), her results may "open it all up again" -- "it" being the scientific and legal controversy that has simmered for a decade. Plaintiffs who haven't already settled their cases will be able to claim they have new evidence from the federal government on their side. LeRoy Hersh says this would be welcome news: "Women will finally know they aren't crazy." Lawyers on the manufacturers' side, meanwhile, are bracing for the worst. One predicts privately that Brinton's report will associate implants with amorphous symptoms like fatigue, dry eyes, depression, and sore knees. "That's the kind of thing any woman might have," says the attorney, which would be almost impossible to disprove.

Louise Brinton's work should give credence to those in Congress pushing for greater public access to internal documents relating to federally funded scientific research. But regardless of the outcome of Brinton's study, her style is clearly unique.

"It's a question of conflict of interest," says Dr. Robert Capizzi, chairman of the Department of Medicine at Thomas Jefferson Medical College. Capizzi, who is one of the top oncologists in the country, follows the work of the National Cancer Institute closely. "Plaintiffs' lawyers have an ax to grind," he says, "and what Brinton has done is very unusual."

John Meroney is associate editor of the American Enterprise.