Cognitive training for improving executive function in chemotherapy-treated breast cancer survivors

Abstract

Background: A majority of breast cancer (BC) survivors, particularly those treated with chemotherapy, experience long-term cognitive deficits that significantly reduce quality of life. Among the cognitive domains most commonly affected include executive functions (EF), such as working memory, cognitive flexibility, multitasking, planning, and attention. Previous studies in other populations have shown that cognitive training, a behavioral method for treating cognitive deficits, can result in significant improvements in a number of cognitive skills, including EF.

Materials and methods: In this study, we conducted a randomized controlled trial to investigate the feasibility and preliminary effectiveness of a novel, online EF training program in long-term BC survivors. A total of 41 BC survivors (21 active, 20 wait list) completed the 48 session training program over 12 weeks. The participants were, on average, 6 years after therapy.

Results: Cognitive training led to significant improvements in cognitive flexibility, verbal fluency and processing speed, with marginally significant downstream improvements in verbal memory as assessed via standardized measures. Self-ratings of EF skills, including planning, organizing, and task monitoring, also were improved in the active group compared with the wait list group.

Conclusions: Our findings suggest that EF skills may be improved even in long-term survivors by using a computerized, home-based intervention program. These improvements may potentially include subjective EF skills, which suggest a transfer of the training program to real-world behaviors.

Keywords: Chemotherapy; Cognitive flexibility; Memory; Processing speed; Rehabilitation.

Figure 1

Study Schema

Figure 2

Mean Change Scores for Cognitive Outcome Measures. The Active Cognitive Training Group Showed Significantly (P < 05) Increased Scores on Measures of EF Outcome, Including WCST, Letter Fluency, Sym Search, and BRIEF Subscales (denoted by asterisks). HVLT-R Was Marginally Improved (P = 07) Abbreviations: BRIEF = behavioral rating inventory of executive function; EF = executive function; GEC = global executive composite; HVLT-R = Hopkins verbal learning test revised; Ltr Fluency = letter fluency; Sym Search = symbol search; WSCT = Wisconsin card sorting test.