Among cancer patients, higher baseline BDNF levels predicted better self-perceived cognitive abilities (PCA: β = 0.19, 95% CI 0.03 to 0.34, p = 0.020), and improved attention scores (β = 0.04, 95% CI 0.004 to 0.08, p = 0.029) and memory scores (β = 0.05, 95% CI 0.01 to 0.09, p = 0.018) at 3- and 6-months post-baseline. Here, BDNF is linked to cancer.