Abstract P4-12-07: Patients' preferences for postmenopausal hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer treatments in Japan

Abstract

Abstract Background: The objective of this study was to identify factors that affect preferences for treatment of breast cancer (BC) patients in Japan and understand their relative importance. Also this study explored whether patients' sociodemographic and clinical characteristics would affect patient preference in choice of treatment. Methods: A questionnaire for discrete choice experiment (DCE) was developed with five attributes, progression free survival (PFS), incidence of diarrhea (IOD), frequency of diarrhea (FOD) which represents the increase in the number of stools per day than usual, duration of diarrhea (DOD) and route and frequency of administration (RFA) referring MONARCH 2, a global phase III study for abemaciclib plus fulvestrant versus placebo plus fulvestrant in patients with HR+/HER2− advanced BC. Each questionnaire was composed of nine choice sets and each choice set contained those five attributes with different levels. Postmenopausal and HR+ BC patients in Japan who recruited from a patient panel were asked to choose one treatment alternative in each choice set. Conditional logit model was used to identify relative preferences of each attribute. The preference weights were evaluated with βcoefficient and standard error. In addition, conditional logit model including patient-specific covariates, such as patient characteristics (age, employment status, age of children and marital status) and clinical characteristics (experience of relapse or metastasis and with/without hormone sensitivity), was used to identify factors that affect patient preference in choice of treatment. Results: Of 302 respondents recruited, 258 had valid responses and the rest had inappropriate answers for the validity testing choice set. The mean age (SD) was 56.7(6.7), 47.7% had paid employment, median duration since diagnosis was 5.1 years and 98.1% had experienced hormonal therapy. According to the absolute magnitude of coefficients, when the FOD is 6, the order of attributes' relative importance was the following: PFS, DOD, FOD, IOD, RFA. However when the FOD becomes 9, FOD was the most important attribute for patients. All tested attributes were statistically significant (p<.0001) on their preference in choice of treatment. When patient-specific covariates were included in the model, the patients who have had experience of relapse or metastasis showed the strongest preference for the longest PFS of 16 months and the patients who were 45 to 59 years old showed the weakest preference for the highest FOD of 9. Conclusions: Postmenopausal and HR+ BC patients in Japan showed preference for treatments which can extend PFS even with the potentiality of Grade 2 diarrhea by the grading of Common Terminology Criteria for Adverse Events v4.0. Prevention of diarrhea to make it Grade 2 or lower may maintain patients' motivation for the treatment which can extend PFS. This study also showed that patients' sociodemographic and clinical characteristics tend to affect patients' treatment choices. It will be important to choose treatments with considering patients' characteristics such as their life style, age and therapeutic experience. Citation Format: Omori Y, Enatsu S, Cai Z, Ishiguro H. Patients' preferences for postmenopausal hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer treatments in Japan [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-12-07.