Impact of Lung Cancer Treatment on Cognitive Functioning

The impact of oncologic treatment for (non)-small-cell lung cancer (NSCLC and SCLC, respectively) on cognition is relevant when deciding which treatment is the most preferable option, especially when curation is not possible. A systematic search of Medline and EMBASE for studies on the effect of treatment on cognition in patients with lung cancer was performed. A total of 39 longitudinal articles were included. Study populations were heterogeneous with regards to stage and treatment type. In the 7 studies concerning SCLC, the median age of patients was between 59 and 68 years. Eighty-six percent of these studies had a loss to follow-up > 10%. Six studies used objective tests to assess cognition. Objective measurements showed a negative effect on attention, memory, and fluency after treatment. Thirty-three studies concerning NSCLC were included. The mean age of patients was between 53 and 77 years. Seventy percent of these studies included patients with stage III and IV NSCLC. Over one-half of the studies had a high rate of loss to follow-up. Eighty-eight percent used objective scales to assess cognitive functioning. Subjective decline of cognitive functioning up to 11.1% was experienced, with recovery at 4 to 6 months. Objective measurement of attention showed improvement over the course of chemotherapy. In SCLC, there is a significant negative effect on attention, memory, and fluency. In NSCLC, the longer term impact of treatment on both subjective and objective cognitive functioning appears limited. Thus, there is no evidence directing treatment choice for NSCLC based on longer term cognitive deficits. Further research is needed to precisely assess the impact of lung cancer treatment on cognition.