TUESDAY, Feb. 19 (HealthDay News) -- The lack of a chromosome actually helps people with a rare, aggressive brain tumor respond better to a new treatment, new findings show.

Gliomatosis cerebri is a type of inoperable brain tumor that is difficult to diagnosis and has an extremely variable prognosis. A study of 25 people with the condition showed that those missing chromosomes 1p and 19q did vastly better on the chemotherapy drug temozolomide, living an average of four years longer than those without the genetic abnormality.

The study is published in the Feb. 19 issue of Neurology.

"Temozolomide is now our first choice of treatment for patients with gliomatosis cerebri, especially when missing chromosomes 1p and 19q," Dr. Marc Sanson of INSERM, the French government health agency in Paris, said in a prepared statement.

Those in the study underwent genetic testing and received monthly treatments of temozolomide for up to two years. The drug had only recently been proposed as a new treatment for gliomatosis cerebri, Sanson said.

Eighty-eight percent of those missing the chromosomes responded well to the drug compared with only 25 percent of those with the chromosomes, Sanson said. Those without it also survived an average of 5.5 years compared with only 15 months for the group with the chromosomes intact. Those missing 1p and 19q also had more months without the tumor progressing, he added.

"Before now, we weren't sure which factors influenced how well a person with this type of brain tumor would respond to the treatment," Sanson said.

More information

The National Institute of Neurological Disorders and Stroke has more about brain tumors.

-- Kevin McKeever

SOURCE: American Academy of Neurology, news release, Feb. 18, 2008

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