ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Thursday, August 29, 1996 TAG: 9608290057
SECTION: NATIONAL/INTERNATIONAL PAGE: A-9 EDITION: METRO
DATELINE: NEW YORK
SOURCE: Associated Press
Scientists have destroyed or shrunk tumors in lung cancer patients by injecting the cancers with a gene that acts like a brake on the disease. The approach might work with other kinds of tumors, too.
The gene wiped out a tumor in one patient, shrank tumors in two others and made cancers stop growing in three more.
The work is preliminary, but it does show that the treatment is safe and that the gene can kill cancer cells, said researcher Dr. Jack Roth of the University of Texas M.D. Anderson Cancer Center.
Bigger studies will be needed to figure out how much good the treatment does for patients, he said.
The nine patients in the study had very advanced cancer that could not be helped by conventional treatments, Roth and colleagues reported in the September issue of the journal Nature Medicine. All of the patients are now dead because the cancer had spread beyond the treated tumors.
Colon and breast cancers might also respond to injections of the gene, said Dr. John Minna of the University of Texas Southwestern Medical Center in Dallas, who wrote an accompanying commentary on Roth's work.
``I was quite excited by the result,'' Minna said.
The gene is called p53. In its normal state, it keeps cells from turning cancerous. When it is missing or mutated, this brake is lost. That's often what happens in cancer of the colon, breast and lung.
Prior studies have shown if cancer cells lack a working version of p53, an injection of the gene can make the cells commit suicide. Roth and colleagues found signs that this happened in the patients they treated.
Researchers used a virus to carry the p53 gene into tumor cells. They delivered it to the tumor by either slipping a tube down the patient's throat or inserting a needle through the skin. Patients got one treatment a day for five days.
One patient died four months after the treatment because of cancer elsewhere in his body. An autopsy found no sign of cancer where the treated tumor had been.
In another patient, the tumor shrank and tissue samples from the treated area showed no evidence of cancer. But Roth said the area could not be examined as completely as in the patient with the autopsy.
A third patient had tumor shrinkage of more than 50 percent when he died, a month after treatment, of cancer elsewhere and pneumonia.
In the three other patients whose tumors stopped growing for at least eight weeks, untreated cancer elsewhere in the body continued to grow.
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