Testicular cancer can lead to seizures, memory loss and dementia long before the cancer is detected, researchers reported in the third 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 the body's own immune system on a protein produced by tumors, the researchers said.In Wednesday'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, it also is attacked.