Placebo-controlled trials (PCT) in cancer research: Patient and oncologist perspectives.

Abstract

e19626 Background: The ethics involving PCT is controversial, with placebo being perceived as an important barrier to patient enrollment in many countries. Here we have evaluated the perceptions of oncologists and cancer patients living in Brazil on this matter. Methods: Twenty-five research-oriented oncologists from across the country and 100 ambulatory patients with advanced cancer from a single public and academic institution completed two different questionnaires about their understanding and perceptions of placebo use in cancer clinical trials, whether patients would participate in PCT, and when and whether oncologists would offer such trials to their patients. The definitions of placebo and its utilization in cancer trials were based on a recommendation article recently published (Dagherty et al. J Clin Oncol 2008), and consisted of the following statements to endorse cancer trials controlled by placebo: (1) when the existing therapies are minimally effective or may potentially offer serious adverse events, (2) or in the absence of proven effective therapy. A pre-determined brief explanation on placebo and its use in cancer research was provided to patients before they answered the study questionnaire. Results: Among 104 cancer patients, 102 (98%) had never heard of or knew what a PCT was. After the brief explanation, 61 (59%) patients agreed to participate in a PCT, with the main reasons for participating being “to obtain any treatment” or “to help medicine.” The main reasons for not participating were “because I do not want to be treated anymore” or “due to the placebo.” Nearly half (48%) of oncologists had objections to offer a PCT to patients, with the main reasons being “feeling that the patients would not accept it” and “I feel uncomfortable about not offering any treatment to my patients.” None of the tested variables (educational level, gender, prior knowledge about clinical trials) was associated with patients' acceptance to enroll in a PCT. Conclusions: PCT trials are perceived as an important barrier to trial participation by both Brazilian cancer patients and their oncologists. New cancer trials should develop alternative designs to fulfill patients and physicians preferences. No significant financial relationships to disclose.