Abstract PS9-61: Incidence of intravenous (IV) hydration post anthracycline-cyclophosphamide (AC) chemotherapy in breast cancer patients
Authors: Navari Rudolph M. , Mosier Michael C. 
Published: February 2021

Background: Managing delayed chemotherapy-induced nausea and vomiting (CINV) associated with highly emetogenic chemotherapy (HEC) is an unmet need. AC-based HEC is often administered to breast cancer patients. The National Comprehensive Cancer Network and American Society of Clinical Oncology antiemetic guidelines recommend that if breakthrough CINV occurs, treatment should include an antiemetic agent from a different class not used in prophylaxis, as well as intravenous hydration and/or dexamethasone. The primary objective of this study is to retrospectively determine the incidence of IV hydration in post AC chemotherapy in breast cancer patients.

Methods: The charts of 270 breast cancer patients receiving AC chemotherapy at University of Alabama at Birmingham (UAB) and on initial 3-drug prophylactic antiemetic regimens were retrospectively reviewed to determine the frequency, incidence, and timing of IV hydration. The hydration incidence was determined for 4 consecutive cycles of AC chemotherapy. The need for hydration was recorded post chemotherapy (e.g., nausea, vomiting, anorexia, loss of appetite, decreased oral intake). Physician and nurse chart notes were reviewed, including documented hydration visits post AC chemotherapy to outpatient infusion areas, local hospital emergency departments, or local hospital inpatient admissions. This report focuses on the patients who were on a guideline-recommended 3-drug regimen (palonosetron [Palo] + Neurokinin-1 [NK1] + dexamethasone [Dex], or ondansetron [Ond] + NK1 + Dex). These patients were followed and monitored for 4 consecutive cycles of AC chemotherapy, and the incidence of hydrations in different cycles was evaluated.

Results: 270 patients were included in this analysis; 179 patients received Palo + NK1 + Dex (Group 1) and 91 patients received Ond + NK1 + Dex (Group 2) antiemetic regimens. Of the 179 patients in Group 1, 28 (16%) received hydration post chemotherapy, and 20 (22%) of the 91 patients in Group 2 received hydration (P=0.198, Chi-square test). Demographics and clinical characteristics of the 48 patients receiving hydration are presented in the Table. 28 patients in Group 1 had a total of 36 hydrations, the majority (20 [56%]) of which were in Cycle 1. 26/28 patients received rescue antiemetic treatment at the time of hydration, and 11 had a change in their prophylactic antiemetic regimen after hydration in subsequent chemotherapy cycles. Similarly, in Group 2, 20 patients had a total of 25 hydrations, with the majority (13 [52%]) in Cycle 1. 19 patients received rescue antiemetic treatment at the time of hydration, and 10 had a change in their prophylactic antiemetic regimen in subsequent chemotherapy cycles.

Conclusions: The incidence of IV hydration post chemotherapy in breast cancer patients following AC-based HEC regimens occurred predominantly in the first cycle. Unscheduled hydrations, which occur when patients require evaluation in the clinic, and/or emergency department, may be complementary events for breakthrough measurement in CINV and could serve as a surrogate of associated healthcare utilization costs. Further clinical trials may consider evaluating unscheduled hydrations rates as part of a composite complete response endpoint (no breakthrough, no rescue medication, no unscheduled hydration).

Table: Demographic and Antiemetic Regimens for Patients Requiring Post-chemo HydrationGroup 1Group 2Palo + NK1 + DexOnd + NK1 + Dex(n=179)(n=91)Post-chemo hydration, n (%)28 (16)20 (22)Demographics and Clinical Characteristics of Patients with Post-chemo Hydration (n=48)Median age, years (range)s56 (35-73)58 (33-70)Sex, n (%)Female27 (96)20 (100)Male1 (4)0ECOG Performance Status, n (%)015 (53)12 (60)112 (43)7 (35)201 (5)Unknown1 (4)0IV access, n (%)Central26 (93)20 (100)Peripheral2 (7)0Antiemetic Regimens Prior to Chemotherapy and Hydration RequirementsTotal number of patients requiring hydration, n (%)28 (16)20 (22)Total number of hydrations, n3625Number of hydrations in Cycle 1, n (%)20 (56)13 (52)Visits, n (%)Office16 (57)12 (60)Emergency department12 (43)8 (40)Rescue antiemetic(s) at time of hydration, n (%)26 (93)19 (95)Prophylactic antiemetic regimen switched, n (%)11 (39)10 (50)Dex = dexamethasone; ECOG = Eastern Cooperative Oncology Group; IV = intravenous;NK1 = Neurokinin-1; Ond = ondansetron; Palo = palonosetron.

Citation Format: Rudolph M. Navari, Michael C. Mosier. Incidence of intravenous (IV) hydration post anthracycline-cyclophosphamide (AC) chemotherapy in breast cancer patients [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-61.