Therapies for Cognitive Deficits Associated with Chemotherapy for Breast Cancer: A Systematic Review of Objective Outcomes

Objective To systematically review evidence of treatments for cognitive impairments experienced by at least 20% of all women who undergo chemotherapy for breast cancer. Data Sources Searches of 5 databases (PubMed, Embase, Cochrane CENTRAL, PsycINFO, CINAHL), with no date or language restrictions, identified 1701 unique results. Search terms included breast cancer, chemotherapy, chemobrain, chemofog, and terms on cognition and language deficits. Study Selection Included only peer-reviewed journal articles that described therapies for cognitive dysfunction in women undergoing (or who had undergone) chemotherapy for breast cancer and provided objective measurements of cognition or language. Data Extraction Data were extracted according to Cochrane recommendations, including characteristics of participants, interventions, outcomes, and studies. Quality assessment of all 12 eligible studies was performed using the Physiotherapy Evidence Database scale and treatment fidelity criteria. Screening, data extraction, and quality assessment reliability were performed. Data Synthesis Six articles described interventions for cognition that took place during cancer treatment; 6, afterward. Five interventions were medical (including a strength-training program), 2 were restorative, and 5 were cognitive. Medicinal treatments were ineffective; restorative and exercise treatments had mixed results; cognitive therapy had success in varying cognitive domains. The domains most tested and most successfully treated were verbal memory, attention, and processing speed. Conclusions Cognitive therapy protocols delivered after chemotherapy and aimed at improving verbal memory, attention, and processing speed hold the most promise. Future research is needed to clarify whether computerized cognitive training can be effective in treating this population, and to identify objective assessment tools that are sensitive to this disorder.