Effects of tamoxifen on cognition and language in women with breast cancer: A systematic search and a scoping review.

OBJECTIVE: Breast cancer treatments bring adverse consequences that interfere with everyday functioning. Importantly, some of these treatments are associated with cognitive and language changes. Tamoxifen is a selective estrogen receptor modulator and is a common endocrine therapy treatment for breast cancer. The current review examines the specific domains of cognition and language affected by the use of tamoxifen in women with breast cancer. METHODS: We conducted a systematic search that examined cognitive and/or language functions in chemotherapy-naïve women with breast cancer taking tamoxifen. PubMed, Cochrane CENTRAL, CINAHL Complete, PsycINFO, Scopus, EMBASE, and the Grey Literature Report (greylit.org) were searched. Covidence Systematic Review software (covidence.org) was used to manage the screening process of study titles and abstracts as well as full texts. A total of 17 studies were included in the review. RESULTS: A range of cognitive and language domains were reported. These were grouped into seven broad domains: attention, memory, speed, executive functioning, verbal abilities, visual abilities, and language abilities. Results showed that there is compelling evidence that specific domains of memory and speed are negatively affected by the use of tamoxifen. In addition, there was a pattern of change in domains of executive functions and verbal abilities. CONCLUSIONS: Tamoxifen affects specific cognitive and language domains. Language domains beyond semantics have not been studied and thus conclusions related to these domains, and language in general, could not be made. Studies exploring the effects of tamoxifen on the different domains of language are recommended.

When Manual Analysis of 12-Lead ECG Holter Plays a Critical Role in Discovering Unknown Patterns of Increased Arrhythmogenic Risk: A Case Report of a Patient Treated with Tamoxifen and Subsequent Pneumonia in COVID-19.

Several medicines, including cancer therapies, are known to alter the electrophysiological function of ventricular myocytes resulting in abnormal prolongation and dispersion of ventricular repolarization (quantified by multi-lead QTc measurement). This effect could be amplified by other concomitant factors (e.g., combination with other drugs affecting the QT, and/or electrolyte abnormalities, such as especially hypokalemia, hypomagnesaemia, and hypocalcemia). Usually, this condition results in higher risk of torsade de point and other life-threatening arrhythmias, related to unrecognized unpaired cardiac ventricular repolarization reserve (VRR). Being VRR a dynamic phenomenon, QT prolongation might often not be identified during the 10-s standard 12-lead ECG recording at rest, leaving the patient at increased risk for life-threatening event. We report the case of a 49-year woman, undergoing tamoxifen therapy for breast cancer, which alteration of ventricular repolarization reserve, persisting also after correction of concomitant recurrent hypokalemia, was evidenced only after manual measurements of the corrected QT (QTc) interval from selected intervals of the 12-lead ECG Holter monitoring. This otherwise missed finding was fundamental to drive the discontinuation of tamoxifen, shifting to another "safer" therapeutic option, and to avoid the use of potentially arrhythmogenic antibiotics when treating a bilateral pneumonia in recent COVID-19.