Thursday June 10 1:26 AM ET
By JANET McCONNAUGHEY Associated Press Writer
Testicular cancer can lead to seizures, memory loss and dementia long before the cancer is detected, researchers reported today in the hird study to link brain damage to an immune system attack on cancer. The brain damage apparently is caused not by the cancer itself, but by an overly aggressive attack by body's own immune system on a protein produced by tumors, the researchers said.
In today's New England Journal of Medicine, researchers said men with testicular cancer and damage to one of the brain's emotional centers had a particular type of antibody in their blood.
The antibody was found in most of the men's blood long before the cancer was detected, suggesting the antibodies could be used to give patients an early warning of testicular cancer.
Dr. Robert Darnell of Rockefeller University, who has performed similar research but was not involved in this study, said these rare brain disorders could provide clues necessary to develop tumor vaccines and treatments for other degenerative brain diseases.
"They're very important models for how an immune response in the body can get into the brain and cause degeneration," he said. "This is very important for multiple sclerosis and maybe other degenerative diseases."
Researchers think the biological double-whammy happens because a tumor sometimes creates a protein normally found only in the brain.
Since the immune system ordinarily doesn't come across those proteins, it attacks them as invaders. But since the same protein is in the brain, the brain also is attacked.
Dr. Raymond Voltz and colleagues at Memorial Sloan-Kettering Cancer Center in New York tested samples from 986 cancer patients for antibodies to brain proteins.
One was a man who had testicular cancer and brain problems caused by inflammation in the limbic system, a part of the brain important in regulating emotions.
They found an antibody they had never seen before, and checked it against serum from 12 other men. All 12 had both testicular cancer and a related inflammation in either the limbic system or the brain stem. Nine of them also had the antibodies.
Eight of the 10 men with the antibodies didn't have any symptoms of cancer when they went to the doctor for brain problems. The cancer was found six months later, on average, and as long as three years later. Voltz and his colleagues compared the study group with several other types of patients, including those with tumor-related brain damage and people who had cancer but no brain damage. The antibody was unique to the combination of testicular cancer and inflammation of the limbic system or the brain stem.
This suggests that patients, especially young men, who have symptoms of this type of inflammation should be tested for the antibodies as an early check for testicular cancer, the doctors said.
Darnell reported a similar link to brain damage among breast and ovarian cancer patients last fall. A third study reported the link in patients with small-cell lung cancer.
In the study with breast and ovarian cancer, the patients' blood contained immune system T-cells that had attacked both the tumor and the cerebellum, the part of the brain that controls movement. The patients couldn't walk because their legs and arms jerked as if they were being shocked, and they had trouble controlling their eye movements.
The researchers in the new study said they did not know whether the
brain damage is caused by the antibody, a similar killer T-cell response,