Antiemetic Efficacy of Adding Olanzapine 5 mg to Aprepitant, Palonosetron and Dexamethasone-Sparing After Day Two for Cancer Patients Receiving Anthracycline and Cyclophosphamide

Purpose Chemotherapy-induced nausea and vomiting (CINV) decrease patient quality of life (QOL). We evaluated the efficacy of adding 5 mg Olz to a three-drug steroid-sparing antiemetic regimen (aprepitant, palonosetron, and dexamethasone-sparing after day two) for breast cancer (BC) patients receiving anthracycline plus cyclophosphamide (AC) chemotherapy. Patients and methods We retrospectively reviewed the records of 177 BC patients with no previous highly emetogenic chemotherapy history receiving AC plus the steroid-sparing three-drug regimen or the steroid-sparing four-drug regimen including Olz 5mg at our hospital between January 2012 and December 2018. The primary endpoint was complete response (CR), defined as no vomiting and no usage of rescue medication during the first AC cycle. We analyzed the odds ratio (OR) of the CR with 95% confidence interval (CI) in the three-drug group against the four-drug group. The OR was adjusted for types of anticancer drugs by the Cochran-Mantel-Haenszel (CMH) test. Secondary endpoints were incidences of nausea, anorexia, fatigue, and somnolence during the first cycle. Results Compared to the three-drug group, the four-drug group demonstrated high incidence of no vomiting (71% vs 95%), a similar incidence of no rescue medication usage (50% vs 51%), and a similar CR rate (45% vs 49%). The OR of the CR rate in the three-drug group against the four-drug group after CMH adjustment for drug type was 0.958 (95% CI, 0.46-1.98). Compared to the three-drug group, the four-drug group demonstrated identical incidence of nausea (66%), but lower incidences of anorexia (78% vs 35%) and fatigue (86% vs 73%). The incidence of somnolence in the four-drug group was 49%. We did not have data of somnolence for the three-drug group in the records. Conclusion Adding 5 mg Olz to the steroid-sparing three-drug combination can reduce vomiting, anorexia, and fatigue, although there was no difference in CR rate.