RESUMO
PURPOSE: Chemotherapy-induced nausea and vomiting (CINV) is a common adverse event with cancer chemotherapy, despite the availability of effective antiemetic agents. This is a prospective observational study of Italian breast cancer patients treated with anthracycline plus cyclophosphamide (AC), assessed CINV incidence, adherence to national antiemetic guidelines (AIOM 2012), and the relationship with CINV outcomes. METHODS: Patients with breast cancer scheduled to receive their first cycle of an AC-based regimen were enrolled at 12 Italian centers and their clinical data prospectively recorded. CINV incidence was assessed from patient diaries after the first chemotherapy cycle. The relationship between guideline adherence and CINV outcomes was examined using multiple logistic regression. RESULTS: The overall incidence rates of nausea and vomiting among 246 evaluable patients were 63.0 and 25.4%, respectively. Most patients received a 5-HT3-RA agent and dexamethasone for acute phase CINV prophylaxis, whereas a triple combination including aprepitant (NK1-RA), consistent with national guidelines, was used in only 45.5% of cases. In the delayed phase, the guideline adherence was 48.8%, while the overall adherence was 43.5%. After adjusting for confounding factors, adherence to antiemetic prophylaxis guidelines was associated with a significant reduction in the odds of three endpoints, namely any nausea, "significant nausea," and vomiting (OR = 0.49, OR = 0.54, and OR = 0.48, respectively), and a 90% increase in the odds of overall complete protection (OR = 1.90). CONCLUSIONS: CINV is still a critical issue in AC-treated patients, despite antiemetic treatment. Non-adherence to antiemetic guidelines may lead to poorer outcomes and indicates the need for strategies to enhance the use of guidelines in clinical practice.