Antecedentes: Las personas con cáncer presentan quejas cognitivas subjetivas durante o después del tratamiento oncológico que pueden afectar su calidad de vida. La evaluación de estas por medio de instrumentos de autorreporte permite su canalización a atención neuropsicológica. Objetivo: Determinar las propiedades psicométricas del PROMIS® v2.0 Función Cognitiva Forma Breve (SF-8) en una muestra de personas mexicanas con cáncer. Método: 200 personas con promedio de edad de 46.34, mayoritariamente en estadios II y III, en tratamiento activo o seguimiento. Diseño: Instrumental, no experimental transversal.

Background: People with cancer present subjective cognitive complaints during or after cancer treatment that can affect their quality of life. The evaluation of these through self-report instruments allows their referral to neuropsychological care. Objective: To determine the psychometric properties of PROMIS ® v2.0 Cognitive Function Brief Form in a sample of Mexican patients with cancer. Method: A total of 200 people with an average age of 46.34, mostly in Stages II and III, in active treatment or follow-up. Design: Instrumental, non-experimental cross-sectional. Instruments: SF-8 and effects on quality of life subscale of the Cancer Therapy Functional Assessment Instrument-Cognitive Function. Analysis: Factor structure, confirmatory factor analysis, and concurrent validity test.Results: An unifactorial model was obtained that explained 73.27% of the variance, internal consistency index α = 0.99, with high factorial loads (0.69, -0.92), which was corroborated with the confirmatory analysis, with excellent adjustment indexes. The correlation between instruments was r: 0.69 (p < 0.01). Conclusion: The Mexican version of the SF-8 is a valid and reliable instrument for the measurement of subjective cognitive complaints, so its use in the clinical and research field is recommended.