Patterns of dementia diagnosis in surveillance, epidemiology, and end results breast cancer survivors who use chemotherapy.
OBJECTIVE
To determine patterns of dementia diagnosis seen after chemotherapy treatment.


METHODS
Using the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database, International Classification of Diseases, Ninth Revision (ICD-9) diagnoses of dementia occurring in the years after breast cancer diagnosis were examined.


METHODS
The SEER program collects information from population-based tumor registries in seven metropolitan areas (San Francisco and Oakland, Detroit, Atlanta, Seattle, Los Angeles County, San Jose and Monterey Counties, and the greater California area) and eight states (Connecticut, Iowa, New Mexico, Utah, Hawaii, Kentucky, New Jersey, and Louisiana).


METHODS
Eighteen thousand three hundred sixty women diagnosed with Stage II, III, or IV breast cancer.


METHODS
Using validated ICD-9 diagnoses of dementia, the occurrence of dementia and other cognitive impairment in the years after breast cancer diagnosis in women who received chemotherapy was compared with that of women who did not. To account for group differences, propensity score analysis was used to balance the differences in groups before treatment. Risk of dementia was calculated using Cox proportional hazards modeling.


RESULTS
There were significant differences at baseline between individuals who received and did not receive chemotherapy. In the first few years after breast cancer diagnosis, dementia was more common in women who had not had chemotherapy, probably reflecting group differences at baseline. In the longer term, diagnoses of dementia were more common in women who had chemotherapy treatment (hazard ratio=1.20, 95% confidence interval=1.08-1.33).


CONCLUSIONS
These findings suggest the possibility of severe cognitive changes associated with chemotherapy, particularly over the long term.
Heck
Julia E
JE
Department of Epidemiology, Columbia University, New York, New York 10027, USA.
Albert
Steven M
SM
Franco
Rebeca
R
Gorin
Sherri Sheinfeld
SS
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology* / Q000473:pathology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003704:Dementia / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012306:Risk; D018426:SEER Program; D012959:Socioeconomic Factors; D017741:Survivors / Q000706:statistics & numerical data*; D014481:United States
D000970:Antineoplastic Agents