Abstract P1-21-01: Factors affecting enrolment in randomised controlled trials of Japanese patients with metastatic breast cancer
Authors: Hozumi Yasuo , Ohsumi Shozo , Mukai Hirofumi , Takahashi Masato , Akabane Hiromitsu , Park Youngjin , Tokunaga Eriko , Takashima Tsutomu , Watanabe Takanori , Sagara Yoshiaki , Kaneko Tetsuji , Ohashi Yasuo 
Published: March 2020

Background: It is critical that a large proportion of eligible patients should participate in clinical trials. However, recruitment into clinical trials requires informed consent and involves some difficult and complex problems. Therefore, it is important to know what factors affect the participation of eligible patients in clinical trials.

Patients and Methods: Patients with metastatic breast cancer (MBC) who were eligible to participate in the SELECT BC or SELECT BC-CONFIRM trials were recruited to a prospective study accompanying them named SELECT BCFEEL. The SELECT BC and SELECT BC-CONFIRM trials were randomised controlled trials (RCTs) that compared taxanes or anthracyclines, respectively, with the oral regimen of S-1 in the first line setting for Japanese patients with MBC. The SELECT BC FEEL was conducted to identify factors affecting the rates at which informed consent was obtained, using a self-administered questionnaire we developed. The questionnaire included the following items: Physician recommendation, family or friend recommendation, satisfaction with the explanation about the trial, both from the doctor or clinical research coordinator and from printed matter, regimens used, understanding of the concept of the trial, benefit to future patients, relationship with the doctor, attitude toward random assignment, concerns about privacy, burden on the patient, and potential adverse effects. We also asked the patients their age, whether they received prior chemotherapy, and about the time needed to decide whether or not to participate, communication with their doctor or other patients, potential adverse effects they were concerned about, and other people's opinions that affected their decision. The patients were asked to answer most of the questions in 5-point Likert scales. To investigate the associations between patients’ decision regarding whether or not to participate in the RCTs and their responses to each question, the Chi-square test, the Mann-Whitney U test, and the t-test were used. P values of &lt; 0.05 were considered statistically significant.

Results: Two hundred and thirty-two patients participated in the present study. Data were missing for 3 patients, and they were excluded from the analyses. One hundred and eighty five participated in the RCT, but 44 did not. The patients who chose to participate in these RCTs were more likely to answer that they decided to participate because "My doctor wanted me to participate in this trial" (69.2% vs. 25.6%; P &lt;0.001), "My family or friends wanted me to participate in this trial" (46.7% vs. 9.3%; P&lt; 0.001), "Both treatment regimens used in the trial are suitable for me" (48.4% vs. 23.8%; P = 0.004), "I know that the trial is conducted to determine which is a better treatment" (91.9% vs. 76.8%; P = 0.012), and "I think that my participation in the trial will contribute to the benefit of future patients with the same disease" (96.2% vs. 84.1%; P = 0.008), and spent fewer days making a decision (P =0.017) in comparison with those who declined to participate. The answering direction was reversed in only one question: those who answered "I am worried about the fact that I cannot choose which treatment to receive if I participate in the trial" were less likely to participate (46.4% vs. 67.4%; P = 0.010). The persons who had the greatest influence on the decision also differed significantly between the two groups (P = 0.005). Those who chose to participate were more likely to answer that "their doctors" were most influential (66.1% vs. 39.5%), but those who declined answered "their family" (22.8% vs. 46.5%) more frequently than the participants.

Conclusions: To enhance the consent rate in randomised trials of Japanese breast cancer patients, the concepts of the trials must be considered important and acceptable by the doctors and families of the patients.

Citation Format: Yasuo Hozumi, Shozo Ohsumi, Hirofumi Mukai, Masato Takahashi, Hiromitsu Akabane, Youngjin Park, Eriko Tokunaga, Tsutomu Takashima, Takanori Watanabe, Yoshiaki Sagara, Tetsuji Kaneko, Yasuo Ohashi. Factors affecting enrolment in randomised controlled trials of Japanese patients with metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-21-01.