Two Harvard doctors have developed a treatment based on a new protein agent which they believe is a potential cure for lung cancer and possibly for many types of deadly tumors.

The doctors, whose pioneering work was conducted over the last two years at the Harvard-affiliated Massachusetts General Hospital, will announce today in Copenhagen that they have discovered a process, using a protein, to enhance the body's natural ability to slow and reverse tumor growth.

The treatment, according to the doctors, increases the number of the body's lymphocytes, or disease-fighting white blood cells, present in the area of a cancer. Using a wellknown protein substance, the doctors said they were able to artificially stimulate the growth of lymphocytes and then inject the cells back into the blood stream to fight the tumor.

After testing the process on mice, the doctors completed experiments with three lung cancer patients. In two cases, the lung cancer was reduced by 25 percent, and in one case, the new treatment completely defeated the tumor. None of the patients experienced any side effects, according to the doctors.

They cautioned, however, that at least one more year of experiments and about 10 more patients would have to receive the treatment before they could claim success in fighting lung cancers. It could be longer, according to officials, before the treatment could be tried and applied to other forms of cancers.

Optimistic

"We have measured reduction in tumor size in some patients," Dr. Richard L. Kradin, an instructor in pathology at the Medical School and a developer of the treatment, said in an interview yesterday. "We are encouraged, but it is much to early to say if those results will translate into improved and prolonged life for these patients."

"There does appear to be some relationship between the number of lymphocytes at the tumor site and the patients's prognosis," Dr. James T. Kurnick, assistant professor of pathology at the Medical School and the other researcher of the treatment, said in a statement.

"Generally, the prognosis will be better if there are large numbers of lymphocytes present, provided they are shown to be reactive against the tumor," he said.

According to the American Cancer Society, lung cancer is the leading form of cancer among men and one of the leading forms among women. Some 144,000 new cases are diagnosed annually.

A complete study of the doctors' treatment will be released in the Journal of Clinical Immunology and Immunopathology at the end of this year.

The Study

The study, funded by a grant from the Upjohn Company, began by extracting a portion of live tumor in a patient suffering from adenocarcinoma, a type of lung cancer common to emphysema patients. The doctors mixed the removed tumor with a protein called Interleukin 2, which stimulates the growth of the lymphocytes normally present in the extracted tumor.

They then removed the lymphocytes from the mixture and injected them back into the bloodstream, helping the body to destroy the disease.

Cancers, considered one of the fastest and most uncontrollable of all growths, have proved so deadly since doctors have not yet perfected agents either to inhibit the unrestricted growth or to destroy an existing tumor.