Barriers to clinical trial recruitment in head and neck cancer.

Despite substantial improvements in the treatment of head and neck cancer (HNC) over the last two decades, overall survival rates remain unsatisfactory. The need for improved therapeutic approaches for HNC patients is hampered by low patient recruitment rates in HNC clinical trials, particularly Phase III studies. Based on an analysis of ClinicalTrials.gov, this article identified several potential barriers to patient recruitment in Phase I-III clinical trials of treatments for HNC. Of 694 HNC trials identified on ClinicalTrials.gov from multiple sites worldwide, 91 (13.1%) were identified as either terminated, suspended or withdrawn; 27.5% (n=25) of these did not provide an additional reason for stopping recruitment early. Insufficient accrual was the most common reason provided for trial closure (n=23, 25.3%). Possible reasons for the insufficient accrual rates include the inappropriate designs of these studies given the change in HNC tumour biology in the last 20years, the low incidence of the disease, and the diversity of treatment standards and referral processes across countries. Given the low numbers of drugs approved for HNC, it is important that barriers to recruitment in this field are addressed to allow new therapies to be successfully validated in completed clinical trials. This review discusses how these accrual challenges may be overcome with changes to clinical trial designs, including their adaptation to specific subgroups, such as human papillomavirus-positive patients.