Aim: Previous reports suggest that psychological distress, rather than chemotherapy, is the main predictor of self-reported cognitive problems following cancer treatment. Our aim was to compare the associations of distress and cancer treatment with self-reported cognitive failures in breast cancer survivors.
Methods: All breast cancer patients treated during 2009 at Aarhus University Hospital were asked to complete the Cognitive Failures Questionnaire (CFQ) and the Symptoms Checklist-90-R in the fall of 2011.
Results: Of 992 eligible survivors, a total of 683 (68.8%) (mean age: 60.5 years) agreed to participate, with 301 (49.8%) having received chemotherapy. Significant differences between the chemotherapy and non-chemotherapy group were observed for age, education, psychological distress, and somatic symptoms (p<0.001). CFQ total score was significantly correlated with age, psychological distress, and somatic symptoms (r= -0.26 - 0.54, all p<0.001), but not education. When adjusting for these variables, a significant difference was found between CFQ scores of the chemotherapy (mean=33.7; SD=16.5) and the non-chemotherapy group (mean=23.8, SD=13.6), (F(1,535)=8.37, p<0.01). A multiple linear regression with age, psychological distress, somatic symptoms, and chemotherapy vs. no chemotherapy entered as predictors explained a significant proportion of the variance in CFQ scores (R2=0.37; F(4,535)= 79.37; p<0.001). Psychological distress was the best predictor (β= 0.36; p<0.001; 95% CI(B): 0.47-0.73), followed by somatic symptoms (β= 0.25; p<0.001; 95% CI(B): 0.26-0.52). Chemotherapy remained a significant predictor when adjusting for the remaining variables (β= 0.12; p<0.01; 95% CI: 1.19-6.23), yielding a small, yet significant improvement of the overall model (∆R2= 0.010).
Conclusions: Breast cancer survivors who had received chemotherapy reported higher levels of cognitive failures than other survivors. Our results supported previous findings that psychological distress is the main predictor of self-reported cognitive problems. However, our results also indicated that having received chemotherapy remained a small, but significant, predictor of self-reported cognitive failures.