It took Winston Churchill to popularize antibiotic medicine," says William Donald Kelley, 54, in a reference to penicillin curing the English leader's pneumonia. "Steve McQueen will do the same for metabolic therapy." While the outcome of McQueen's grim struggle with cancer (preceding story) is still unknown, there is little doubt that Kelley, a formerly obscure Fort Worth orthodontist, is fulfilling his own prophecy. Within days of leaking the news that he was treating the movie star with his unorthodox nutritional methods, Kelley flew to L.A., arranged a press conference and appeared on Tom Snyder's Tomorrow show. Millions heard Kelley advocate his "nonspecific metabolic therapy," which includes a computerized program of diet, nutritional supplements and "detoxification" by coffee enemas and fasts.

But while Kelley's theories may offer hope to the desperate, his background is less reassuring. He is not an M.D. Even his orthodontist's license was suspended in 1976 for five years after patients complained he was more interested in treating other health problems than in straightening teeth. Over the years he reportedly has been investigated by some 15 government organizations from the IRS to the Food and Drug Administration. "In their sincere efforts to weed out the real quacks," Kelley protests, "these agencies sometimes get overzealous."

Kelley claims he is a living testament to the merits of metabolic therapy. In 1962 he says he had cancer of the liver and pancreas and was given only eight weeks to live. "I freaked out," he remembers. "All your friends and relatives are ready to put you in a box when they hear the word 'cancer.' " Kelley says he cured himself by adhering to a strict diet of liver, pancreatic enzymes, exercise and positive thinking. He compiled his theories in a book, One Answer to Cancer, banned in Texas by court order in 1969 as an unlawful effort to practice medicine.

Undeterred, Kelley has since established the International Health Institute, a privately endowed consulting firm in Dallas that he says has programmed nutritional guidelines for some 20,000 persons. Kelley claims a 15 to 20 percent cure rate for last-stage cancer victims and 60 to 80 percent success with those less seriously ill. His figures are unsubstantiated, but Kelley says, "Our research meets all the requirements of a science."

Born in Arkansas City, Kans., Kelley was raised by a widowed mother who supported the family by delivering dairy products. He majored in physical sciences, earned a master's in education and then studied dentistry at Baylor University. Kelley set up practice in Fort Worth and later Grapevine, Texas, where he dabbled in holistic orthodontia and started a mail-order vitamin business. The four children from an early marriage were recipients of his nutritional practices. "I grew up on goat's milk, carrot brownies and black molasses," says his oldest daughter, Kim, 21, who now works as his administrative assistant.

In addition to the Dallas facility, Kelley also owns a 160-acre farm in Washington, where he met McQueen in late April. "When I first saw him I was horrified," admits Kelley's present wife, Suzi, 34. "He said the doctors gave him no hope." Kelley thinks otherwise. "His chances are excellent if he has the discipline to follow the program," Kelley says. "I believe with all my heart that this approach represents the future of cancer therapy."