Factors affecting the offering and enrollment of patients on clinical trials in radiation oncology.

Abstract

e17571 Background: Improvements in cancer treatment require significant patient involvement in research, which may be particularly limited for new technologies such as proton radiation therapy. Studies with biased referrals or enrollment may not be generalizable to a general population. This study examines the reasons why patients were not offered or refused enrollment in clinical trials at the University of Florida Proton Therapy Institute (UFPTI). Methods: All patients seen at UFPTI between April-October 2012 for proton therapy for tumor sites with a clinical trial available (N=463) had information collected prospectively regarding whether they were offered enrollment and consented for clinical trials, and the reasons for each decision. The majority of patients had already secured funding for proton therapy. Results: Seven percent (34/463) of patients were ineligible for an available clinical trial, due to study exclusion criteria, concerns for patient safety based on comorbidity, or concerns for data integrity (e.g., other non-skin cancer within five years). Only 3% (9/275) of eligible patients were not offered a clinical trial. Forty-four percent (99/226) of patients offered a clinical trial refused. The most common reasons for refusal included: discomfort with lack of mature data, dislike of protocol, fear that protocol is not best option for disease control, and fear of side effects. Although UFPTI treats a variety of malignancies, the overwhelming majority of those who refused consent were prostate adenocarcinoma patients, who often self-referred for proton therapy. Conclusions: Despite near universal availability of clinical trials at UFPTI, less than half of patients enroll in clinical trials. The greatest factor for non-enrollment appears to be patient acceptance. Despite the availability of non-randomized trials with fairly standard treatment approaches, 44% refused to enroll on clinical trials, suggesting discomfort for less well documented treatment approaches. Further studies should examine whether findings are similar among all US cancer patients, as patients seeking proton therapy may not resemble the general population.