TUESDAY, May 31, 2005 (HealthDay News) -- Cancer survivors have an increased risk of long-term cognitive dysfunction and dementia, says a University of Southern California study in the June 1 issue of the Journal of the National Cancer Institute.
The study looked at 702 cancer survivors and their cancer-free twins. It found that all cancer survivors and those who had survived cancer for at least five years were twice as likely as their cancer-free twins to have cognitive dysfunction.
Cancer survivors were also twice as likely to be diagnosed with dementia, but the researchers said this finding was not statistically significant.
"Our data suggest that cancer and its treatments may lower survivors' cognitive reserve and thus increase their long-term risk of cognitive dysfunction and dementia, a serious clinical concern for physicians treating cancer survivors," the study authors wrote.
"Further research should identify mechanisms that mediate the relationship between cancer and cognitive dysfunction, and explore whether specific treatments are associated with long-term cognitive effects. This knowledge will help health-care providers and patients make informed decisions about treatments," the authors added.
An accompanying editorial in the same issue urged caution when interpreting the findings.
"Recent studies have demonstrated that cognitive dysfunction may be present before treatment, may worsen acutely secondary to treatment-related neurotoxicity, and may continue after cessation of therapy," Jeffrey S. Wefel and Christina A Myers of the University of Texas M. D. Anderson Cancer Center, wrote in the editorial.
They said more research is needed to determine which cancer treatments are the most neurotoxic, how and which cognitive and behavioral domains are most affected, and the risk factors for this neurotoxicity.
More information
The U.S. National Cancer Institute has information about life after cancer treatment.
