Characteristics and Outcomes of Patients With Advanced Gastric Cancer Who Declined to Participate in a Randomized Clinical Chemotherapy Trial

Copyright © 2011 by American Society of Clinical Oncology
Characteristics and Outcomes of Patients With Advanced Gastric Cancer Who Declined to Participate in a Randomized Clinical Chemotherapy Trial

Chiharu Tanai, MD, Takako Eguchi Nakajima, MD, PhD⇓, Kengo Nagashima, Ken Kato, MD, PhD, Tetsuya Hamaguchi, MD, PhD, Yasuhide Yamada, MD, PhD, FACP, Kei Muro, MD, Kuniaki Shirao, MD, PhD, Hideo Kunitoh, MD, Yasuhiro Matsumura, MD, PhD, Seiichiro Yamamoto, PhD and Yasuhiro Shimada, MD+

Author Affiliations

Medical Oncology Division, National Cancer Center Hospital, Tokyo; Faculty of Pharmaceutical Science, Josai University, Saitama; Medical Oncology Division, Aichi Cancer Central, Aichi; Medical Oncology Division, Oita University, Oita; Investigative Treatment Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Chiba; Cancer Information Services and Surveillance Division, Center for Cancer Control and Information Services, National Cancer Center, Tokyo, Japan

Corresponding author: Takako Eguchi Nakajima, MD, PhD, Gastrointestinal Oncology Division, National Cancer Center Hospital, Tokyo, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan; e-mail: tnakajima@marianna-u.ac.jp.


Abstract
Purpose:There is insufficient data to verify whether participation in clinical trials in itself can lead to better clinical outcomes. We have analyzed the characteristics and outcomes of patients who declined to participate in a randomized trial in comparison with those who participated in the trial.

Patients and Methods:A randomized trial for naive advanced gastric cancer was offered to 286 patients. The trial investigated the superiority of irinotecan plus cisplatin and the noninferiority of S-1 compared with continuous fluorouracil infusion. We retrospectively reviewed the characteristics and outcomes for both participants and nonparticipants in this trial.

Results:Of the 286 patients, 98 (34%) declined to participate in the trial. The rate of declining was significantly higher among younger patients (P = .003), and it varied significantly between attending physicians (range, 23% to 58%; P = .004). There were no other significant correlations between rate of declining and patient characteristics. No significant differences were observed in the clinical outcomes between the participants and nonparticipants, for whom the median survival times were 367 versus 347 days, respectively. The hazard ratio for overall survival, adjusted for other confounding variables, was 1.21 (95% CI, 0.91 to 1.60). No interaction was observed between participation and the various regimens.

Conclusion:There was no difference in clinical outcomes between participants and nonparticipants. However, the patient's age and the doctor-patient relationship may have an effect on patient accrual to randomized trials.

Accepted September 28, 2010.
Characteristics and Outcomes of Patients With Advanced Gastric Cancer Who Declined to Participate in a Randomized Clinical Chemotherapy Trial