Cognitive problems of breast cancer survivors on proton pump inhibitors

Purpose Proton pump inhibitors (PPIs) are used in cancer patients to manage treatment-related gastrointestinal symptoms and to prevent damage to the gastric mucosal lining during treatment. However, PPI use may contribute to cognitive problems. To compare PPI-users and non-users, breast cancer survivors reported cognitive problems in three studies. Methods In Study 1, breast cancer survivors (N = 209; n = 173 non-users, n = 36 PPI-users; stages 0-IIIC) rated their cognitive function on the Kohli scale prior to cancer treatment, as well as one and two years later. In Study 2, women (N = 200; n = 169 non-users, n = 31 PPI-users, stages 0-IIIa, M = 11 months post-treatment) rated their cognitive function on the Kohli scale and BCPT checklist at three visits over a six-month period. In Study 3, participants (N = 142; n = 121 non-users, n = 21 PPI-users; stages I-IIIa, M = 4 years post-treatment) rated their cognitive function on the Kohli scale, BCPT checklist, and Functional Assessment of Cancer Therapy cognitive scale (FACT-cog). Results In Study 1, PPI-users reported more severe concentration problems (p = 0.039) but not memory problems (p = 0.17) than non-users. In Study 2, PPI-users reported more severe concentration problems (p = 0.022) than non-users, but not memory problems or symptoms on the BCPT (ps = 0.11). Study 3's PPI-users reported more severe memory problems (p = 0.002), poorer overall cognitive function (p = 0.006), lower quality of life related to cognitive problems (p = 0.005), greater perceived cognitive impairment (p = 0.013), and poorer cognitive abilities (p = 0.046), but not more severe concentration problems (p = 0.16), compared to non-users. Conclusions/implications PPI use may impair breast cancer survivors' memory, concentration, and quality of life.