The acting FDA commissioner's decision to keep his old job as the government's chief cancer researcher is being questioned by lawmakers and health experts. They say he cannot do both jobs effectively and may face conflicts of interest.

Dr. Andrew von Eschenbach (search), who is wearing two hats as the new FDA chief and the head of the National Cancer Institute, could face conflicts if the FDA must make a decision on a cancer treatment he helped to develop.

The National Cancer Institute (search), part of the National Institutes of Health, funds research into new cancer treatments, often in partnership with drug companies. The Food and Drug Administration, meanwhile, regulates the results of that research, deciding whether the new treatments are safe and effective enough to permit sales to the general public.

"It's a foot in both camps," said Marc Scheineson (search), a former FDA associate commissioner who is now a partner in the Alston and Bird law firm in Washington. "He's going to quickly have to decide where to put his foot. You have to be on one side or the other."

Arthur Caplan, professor of bioethics and the University of Pennsylvania, said von Eschenbach would have to recuse himself from any decisions related to the National Cancer Institute.

"It just won't wash otherwise," Caplan said.

A spokeswoman for the Department of Health and Human Services, which oversees the FDA, said she was researching the issue but had no immediate comment.

Caplan and others said a greater issue facing Von Eschenbach will be his having to split time between two senior positions.

Von Eschenbach said in a recent interview that he could handle both roles. "From the point of view of commitment, it's 100 percent to both," he said.

But some aren't so sure.

"I don't know how he's going to do it. Maybe he doesn't realize how big a job it is," said Abbey Meyers, president of the National Organization for Rare Disorders. She called von Eschenbach a devoted researcher, although she also questioned the wisdom of his stated goal of eliminating suffering and death due to cancer, turning it into a manageable disease by 2015.

"I hope he's right," she said. "I don't know if he should be so optimistic."

In a letter to White House Chief of Staff Andrew Card, Sen. Charles E. Grassley, R-Iowa, said, "I expect that whoever is named commissioner, either acting or confirmed, will know that it's not possible to give the FDA the kind of strong new leadership that is needed to reinvigorate the agency on a part-time basis."

Grassley, who has spent 18 months investigating the FDA, made the letter public Monday.

Rep. Rosa DeLauro (search) of Connecticut, the top Democrat of the House subcommittee with jurisdiction over the FDA budget, called for the Bush administration to lay out a timeline for selecting a permanent commissioner.

"Now is clearly not the time for a part-time director at FDA with another prolonged period of temporary leadership," she said in a statement. "Irrespective of Dr. Von Eschenbach's qualifications, such an arrangement would undoubtedly compromise the distinct missions of both the FDA and the NCI. We cannot afford to weaken these two agencies."

Von Eschenbach has given no indication whether he expected to be nominated as permanent chief of the FDA.

He replaces Lester Crawford (search), who resigned only two months after the Senate confirmed him for the post. Crawford had functioned as acting head for more than year before that, and his surprise resignation Friday gave no specific reason for his departure.

Crawford's tenure was marked by increasing criticism of the agency by those who contended it had become more interested in politics or benefiting drug companies than in its mission to protect consumers.

Between all the criticism and turnover, the FDA needs a strong leader who can provide some stability and direction, several experts said.