NEW YORK, Jan 28 (Reuters Health) -- A combination of gene therapy and a
traditional cancer-fighting drug appear to be of some help to lung cancer
patients who have failed all other treatments, results of a new study suggest.
The treatment was attempted in 24 lung cancer patients who had tumors with
a mutation in the p53 gene. The p53 gene is a powerful tumor suppressor that is
mutated in 40% to 74% of non-small-cell lung cancers, the most common type of
lung cancer.
Dr. John Nemunaitis of Physicians Reliance Network Research in Dallas,
Texas, and colleagues linked a functioning copy of the p53 gene to an
adenovirus, a relatively harmless cold virus.
According to their report, published in the January 28th issue of the
Journal of Clinical Oncology, the researchers gave the non-small-cell lung
cancer patients the chemotherapy drug cisplatin and then injected the
p53-carrying virus into a single tumor site several days later. The treatment
was repeated up to six times a month.
Overall, cancer progression remained stable in 17 patients and 2 patients
achieved a partial response, according to the authors. Four patients had their
disease progress and one patient could not be evaluated. The treatment was most
effective in six patients who had received the highest dose of adenovirus and
had previously failed chemotherapy with cisplatin or carboplatin, another
cancer-fighting drug.
Samples of tumors taken from near the injection site showed more death in
the tumors than before treatment. Expression of p53 from the adenovirus could be
detected in 43% of 14 tumors.
However, 22 of the patients have died since the study was conducted, with
an average survival time of 164 days. That result was not surprising given the
advanced nature of the patients' disease, the researchers explain.
Since most of the patients had extensive disease and had adenovirus
injections in only one tumor site, tumors located elsewhere in the body tended
to progress and limit survival, noted Nemunaitis in a statement issued by the
journal.
"This should be looked at as a strategy that can be used on single solid
tumors earlier in the disease process," he said.
However, p53 gene therapy offers future promise, according to the Texas
researcher. "The science that has for so long been looked at in lab is finally
showing that it can work in people," Nemunaitis said. "It can be delivered to a
cancer cell and it can kill that cancer."
