Dr. Arthur C. Upton, the new director of the National Cancer Institute, said yesterday that he will discuss with federal officials the possibility of using medically pure heroin on terminally ill cancer patients to alleviate suffering.

The British government licenses hospital doctors to administer heroin to such patients when other drugs, such as morphine, are insufficient to relieve pain. Few public officials in this country have advocated such a course in the belief that it would be politically impossible.

But Upton, was appeared yesterday on "Meet the Press" (NBC, WRC), said after the program that where it is possible to relieve unnecessary suffering, he would like to do so. Some 375,000 Americans will die of cancer this year, or about, 1,000 a day.

Upton, whose institute controls 90 per cent of the federal funds used in cancer research, said he is "optimistic" that the coming decade will bring advances in the fight against common forms of cancer, such as acute leukemia in children and Hodgkins disease, he said, the medical advances "border on the miraculous," with survival rates after five years approaching 50 per cent and 80 per cent respectively.

"We have not seen such dramatic advances in the treatment of most solid tumors, those that occur most commonly in adults," Upton said. "I don't think myself that this is cause for pessimism."

Upton also told a reporter that he is concerned about conflicts of interest and relationships between companies and institutions that get cancer research grants and the people who make them.

"I'll be looking into this question very carefully," he said.

Upton said there will be a meeting at the institute next month to examine evidence of whether radiation from Xrays to diagnose cancer may present a risk of cancer, particularly for women under 50 who get their breasts examined.

Upton said scientists until recently have been skeptical that such a risk exists with "these very small levels of radiation," but added that there has been a reassessment.

"We can't say the risks actually do exist," "but it would seem prudent to assume that they may exist . . . the profession, radiologists, the medical educators, are now preaching the gospel that the [X-ray] dosebly be made consistent with good technique."

Upton called the federal ban on sacharin "good basic public policy." He said there is a close correlation between carcinogenic activity in animals and in people. High doses of the artificial sweetener were administered to laboratory rats and caused cancer of the bladder. Upton said it appears likely that as the dose of saccharin is lowered, the risk of cancer also goes down, "but we cannot be sure that it ever goes to zero."

He said he personally feels saccharin should be made available over the counter to people who feel they need it, but not generally available at the grocery store in soft drinks and other diet products.

Upton also said he will be meeting in the next few weeks with the Food and Drug Administration and other federal officials to determine whether the controversial substance laetrile should be tested on animals. The FDA says it is not cancer cure.

He said there is no data on the efficacy of laetrile on animals, and the only evidence on how well it works on people is "anecdotal," evidence he called "inconclusive."