Abstract PO1-11-12: Factors associated with treatment failure for chemotherapy-induced nausea and vomiting (CINV) among breast cancer patients receiving adjuvant chemotherapy
Authors: Yeo Winnie , Ngai Nicole , Yeo Horatio , Lai Dong , Pang Elizabeth , Kwok Carol , Lau Thomas , Mo Frankie 
Published: May 2024

Abstract
Background Cancer patients often consider CINV as one of the most disturbing side effects of cytotoxic chemotherapy. Adriamycin and cyclophosphamide (AC), considered by many to be part of the standard adjuvant regimen for breast cancer patients, is highly emetogenic. Despite adopting optimal antiemetic prophylaxis, the control of CINV remains modest for some patients. Among Chinese breast cancer patients receiving adjuvant AC chemotherapy, the present analysis aims to determine the association of the number of risk factors for CINV with (i) likelihood of antiemetic treatment failure; (ii) time to first vomiting in 1st AC cycle. Methods: We retrieved data from three previously reported prospective antiemetic studies on patients who received AC, in whom different antiemetic regimens were administered. Treatment failure was defined as (i) not achieving CR (CR= no vomiting and no use of rescue medication over 120 hours after start of AC), or (ii) experiencing nausea (nausea VAS &gt;/= 5mm during the 120 hours). Multivariate logistic regression models were applied to identify potential factors associated with the development of CINV. The Cochran–Armitage trend test was utilized to assess possible trends in the relationship between treatment failure and number of identified risk factors. The time-to-treatment failure curves, as classified by the number of identified factors in each subgroup, were evaluated using the Kaplan–Meier method. Results: Based on multivariate analysis of 303 breast cancer patients, not achieving CR was more likely among non-obese patients, not receiving guideline recommended prophylactic antiemetic regimens, history of motion sickness and history of vomiting in pregnancy. Experience of nausea was more likely in non-obese patients, not receiving guideline recommended prophylactic antiemetic regimens, and history of motion sickness. Treatment failure in terms of ‘no CR’ was associated with increased number of risk factors that an individual patient displayed; the figures increased from 18.8% for those with 0 risk factor to 94.1% for those with 4 risk factors (p &lt; 0.0001). Treatment failure in terms of nausea was associated also with increased number of risk factors; the figures increased from 25.9% for those with 0 risk factor to 83.3% for patients with 3 risk factors (p &lt; 0.0001).
Time to first vomiting was significantly related to number of identified factors (p &lt; 0.0001). Among patients who had 0, 1, 2 and 3 risk factors, the 24-hour rate of ‘no vomiting’ were 81.3%, 80.3%, 66.7%, 53.7% and 17.7%, respectively; similar trends were observed for analyses on 48-hour and 72-hour rates. Conclusions: The present study confirmed that reported risk factors for CINV in the literature were important in Chinese breast cancer patients receiving AC chemotherapy. Furthermore, patients who had more risk factors had increased likelihood of treatment failure and shorter time to first vomiting. Funding: Madam Diana Hon Fun Kong Donation for Cancer Research
Citation Format: Winnie Yeo, Nicole Ngai, Horatio Yeo, Dong Lai, Elizabeth Pang, Carol Kwok, Thomas Lau, Frankie Mo. Factors associated with treatment failure for chemotherapy-induced nausea and vomiting (CINV) among breast cancer patients receiving adjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-11-12.