Study casts doubt on notion of 'chemobrain'.(News)

CHICAGO -- There was no association between the use of chemotherapy in women with breast cancer and a subsequent dementia diagnosis in the first study to rely on a large, retrospective population-based claims database.

Several studies have reported an increase in cognitive impairment, or "chemobrain," among cancer survivors who have undergone adjuvant chemotherapy. But those studies have been critiqued for their small size, lack of an independent control group, poor measures of premorbid function, and inadequate control for cancer stage or hormone receptor status, Sherri Sheinfeld Gorin, Ph.D., and Julia Heck, Ph.D., reported in a poster at the annual meeting of the American Geriatrics Society.

The current study included 49,312 Medicare enrollees age 65 years and older who were diagnosed with breast cancer between 1992 and 1999, and identified by the Surveillance, Epidemiology, and End Results (SEER) Medicare database. Administrative codes for dementia diagnoses and chemotherapy were taken from Medicare claims.

Logistic regression analysis was used to evaluate the relationship between adjuvant therapy use and later dementia diagnosis. Propensity score analysis was used to control for cofactors including ...