423PEffectiveness of first-generation 5HT3 receptor antagonist plus dexamethasone plus aprepitant in controlling delayed chemotherapy-induced nausea and vomiting in patients with colorectal cancer: A propensity score-matched analysis

Abstract Background Delayed chemotherapy-induced nausea and vomiting (CINV) is not well controlled in patients with colorectal cancer (CRC) treated with oxaliplatin (L-OHP)-based chemotherapy. Whether adding a neurokinin-1 receptor antagonist to a first-generation 5HT3 antagonist (1st-5HT3RA) and dexamethasone (DEX) is beneficial in patients on L-OHP-based chemotherapy is controversial. It is unclear whether palonosetron (PALO) or aprepitant (APR) is more effective in controlling delayed CINV. We, therefore, investigated whether PALO+DEX (PALO group) or 1st-5HT3RA+DEX+APR (APR group) was more effective in controlling delayed CINV, as well as risk factors for delayed CINV, in patients with CRC treated with L-OHP-based chemotherapy. Methods We pooled data from two prospective observational studies in Japan and one phase III clinical trial and compared the incidence of CINV between the PALO and APR groups using propensity score-matched analysis. Risk factors for CINV were identified using logistic regression models. Results Among the 404 eligible patients, those in the PALO group showed a higher incidence of delayed CINV than those in the APR group (nausea: 43.4% vs. 32.4%, P = 0.061; vomiting: 12.5% vs. 4.4%, P = 0.017). The logistic regression analysis identified alcohol consumption, motion sickness, and PALO+DEX regimen as independent risk factors for delayed nausea, and female sex and PALO+DEX regimen as those for delayed vomiting. Conclusions Treatment with the three antiemetics, including APR, was more effective in controlling delayed CINV than prophylactic treatment with the two antiemetics, including PALO. Thus, patients with CRC receiving L-OHP-based chemotherapy should be treated with three antiemetics, including APR. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.