At the Carter administration's urging, federal health officials are about to consider the use of heroin and marijuana to relieve the pain and suffering sometimes associated with terminal cancer.

National Cancer Institute doctor are to confer next Wednesday with Dr. Peter Bourne, special assistant to President Carter, as the result of a request from Bourne to Dr. Julius Richmond, assistant secretary of health, educational and welfare.

Bourne asked Richmond in a Sept. 21 letter to assess these drugs' medical potential uninfluenced by "bias" because of "public prejudice" against them or their illegal status.

In an unrelated development, doctors at Memorial Sloan-Kettering Cancer Center in New York already expect to start a federally funded heroin trial in advanced cancer patients "within a few months."

Financed by a $200,000 start-up grant from HEW's National Institute on Drug Abuse and using confiscated heroin supplied by the Food and Drug Administration - Memorial's Dr. Raymond Houde will conduct what is planned as a five-year, $1 million study of heroin and several other substances.

Bourne's letter made it clear that he is not sure that heroin will be superior to its chemical cousin, morphine, which is already a legal pain reliever.

Bourne in fact said he was concerned by articles implying that severely suffering individuals are being denied relief by insensitive and uncaring bureaucrats." He said one recent study at the noted St. Christopher's Hospice in London had found heroin no better than morphine for terminally ill cancer patients.

Nonethesess, he asked Richmond to investigate the inactive - from a purely medical standpeict, he emphasized, to avoid any "erroneous accusation" that the Carter administrations "soft" on abusive drug.

Doctors in Britain and some other countries are using heroin for man relief, with some reports saying it is of value to suppress cough in late-stage lung cance.

Three years ago doctors at the Medical College of Virginia and Hichmond said a one-year test indicated that THC, marijuana's active chemical helped cancer patients overcome fear and depression.