A meta-analysis of the effects of chemotherapy on cognition in patients with cancer

Objective: The aim of this meta-analysis was to assess whether chemotherapy-related cognitive impairment is consistently observed in cancer patients and to identify the areas of cognition affected. Methods: The meta-analysis included 13 studies and examined the effects of chemotherapy on seven different cognitive domains, across five cancer types. It was the intention of this meta-analysis to stringently exclude many studies, allowing for examination of cognition in carefully selected studies of chemotherapy recipients who do not have current mood or anxiety diagnoses (or psychiatric or substance abuse histories), without brain cancer and who have not had radiotherapy or hormone treatment. A moderator analysis examined whether patient age, treatment duration and time since treatment end significantly contributed to chemotherapy-related cognitive impairment. Results: Evidence for the presence of cognitive impairment following cancer treatment was established for executive function and memory. No relationship was found between cognitive impairment and time since treatment cessation but a significant negative relationship was found for treatment duration. Age had no impact on treatment-related cognitive impairment. Conclusions: Future research must be conducted on chemotherapy-related cognitive impairment in cancer types such as lymphoma and leukaemia, which have received a moderate amount of attention and colorectal cancer, which has received little attention. This would enable us to determine the extent to which chemotherapy-related cognitive impairment is a universal phenomenon associated with the cancer experience and its treatment regardless of cancer type. (C) 2012 Elsevier Ltd. All rights reserved.