RESUMO
BACKGROUND: Diarrhea is one of the most frequent class adverse events associated with targeted oral antineoplastic agents (OAAs). Our objective was to analyze the incidence, characteristics, and severity of diarrhea in cancer patients in clinical practice. METHODS: An observational, longitudinal, and prospective study of cancer outpatients treated with targeted OAAs was carried out in a tertiary hospital. Targed OAAs analyzed were anaplastic lymphoma kinase inhibitors, BCR-ABL inhibitors, cyclin-dependent kinase inhibitors, epidermal growth factor receptor inhibitors, mTOR inhibitors, poly (ADP-ribose) polymerase inhibitors, and vascular endothelial growth factor receptor inhibitors. Patients were given a data collection form to record daily the number, severity (CTCAE version 5.0), and characteristics of stools during the first 30 days of treatment with OAAs. Multivariate analysis was performed to identify risk factors associated with the incidence of diarrhea. RESULTS: We analyzed 240 patients, of whom 28.7% experienced diarrhea (25.4% grades 1-2 and 3.3% grades 3-4). Patients treated with EGFR and VEGFR inhibitors had a higher incidence of diarrhea. The multivariate analysis revealed that taking the OAA with food was associated with a lower risk of diarrhea (OR = 0.404 [0.205-0.956], p = 0.038). CONCLUSIONS: More than a third of patients in treatment with OAAs presented diarrhea (any grade), and 22.1% of stools were semi-liquid/liquid. In multivariate analysis, taking the OAA on an empty stomach was associated with a statistically significant increase in the incidence of diarrhea.