P4-15-01: High Prevalence of Prospective Memory (PM) Impairment in Early Breast Cancer (EBC) Survivors within 1 Year of Adjuvant Chemotherapy Completion: Novel Findings Concerning Post Chemotherapy Cognitive Effects.

Abstract

Abstract Background Numerous studies have demonstrated that EBC survivors report more memory problems than healthy controls. However, evidence of impairment on objective tests of memory remains inconclusive. Past research has focussed exclusively on retrospective memory (remembering information from the past when asked to do so), but the complaints of EBC patients appear better described as “prospective memory” failures defined as forgetting to carry out in the future previously formed intentions. The effective performance of many day-to-day activities relies on PM and its impairment has negative consequences in everyday life. Despite its high ecological relevance, no study has evaluated PM functioning in EBC survivors. Consequently, we assessed the prevalence of PM impairment among EBC survivors in the year following completion of chemotherapy. Methods We undertook a cross sectional quantitative case-control study aiming to recruit 80 patients from the Ottawa Hospital Regional Cancer Centre and 80 matched healthy controls from the community. Patients were within 1 year of having completed a first course of chemotherapy. A standardized test of prospective memory (Memory for Intention Screening Test) was administered to both groups. Following the International Cognition and Cancer Task Force recommendation (2008), impairment was defined as a score that fell one standard deviation below the mean performance of the control group. Standardized measures of depression (CESD), anxiety (STAI) and fatigue (Fact-F) were also completed. Results Data are available on 36 patients and 18 controls. Age was well balanced between the groups (case-control mean age 54y vs. 51y, respectively, p=.204). Overall PM impairment was observed in 41% of the participants. More importantly, the rate of PM impairment was significantly higher in the EBC group than controls (53% vs 17%; p < 0.005; odds ratio = 5.588; 95% CI=1.376 to 22.7). Multivariate logistic regression showed that PM performance was unaffected by age (p=0.459), depression (p=0.358), anxiety (p=0.512) or fatigue (p=0.595). Conclusions These preliminary findings provide further support for the hypothesis that breast cancer treatment can impair cognitive processes and yield new and important insights into the type of memory problems experienced by EBC survivors. They suggest that a significant proportion of patients exhibit deficits in PM, an aspect of memory involved in effective daily functioning. Our results also suggest that emotional distress and fatigue do not contribute to PM functioning. Further studies in this area should be directed at understanding the severity and duration of PM impairment. Acknowledging and studying this vexing problem in EBC survivors will aid in developing appropriate rehabilitation strategies. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-15-01.