Abstract
PURPOSE: Many improvements in head and neck cancer (HNC) outcomes are related to optimization of radiation therapy (RT) dose, fractionation, normal-tissue sparing, and technology. However, prior work has shown that the literature of randomized controlled trials is dominated by industry-sponsored trials that have lower rates of incorporating RT. We characterized HNC clinical trials, hypothesizing that RT-specific research questions may be relatively underrepresented among HNC randomized controlled trials. METHODS AND MATERIALS: A web query of all open interventional trials on www.ClinicalTrials.gov was performed using search terms "head and neck cancer" and specific HNC subsites. Trial details were captured including the modality used, principal investigator (PI) specialty, funding, and whether the study tested a RT-modality specific hypothesis. Chi-square testing and logistic regression were used to compare groups. RESULTS: There were 841 open HNC trials, including definitive (47.6%) and recurrent/metastatic (41.9%) populations. Most trials (71.7%) were phase I or nonrandomized phase II studies, rather than phase III or randomized phase II (28.3%). Among single-arm studies, most (79.6%) incorporated systemic therapy (ST), and fewer (25.2%) incorporated RT. Even fewer phase III and randomized phase II trials tested an RT-specific hypothesis (11.1%), compared with ST-related hypotheses (77.1%; P < .001); trials were more likely to test an RT-hypothesis if the study PI was a radiation oncologist (20.9% vs 6.0%; P < .001). Among RT trials, most early-phase studies tested novel modalities (eg, stereotactic body radiation therapy, proton therapy), whereas most later-phase studies tested dose and fractionation. RT-focused trials had low rates of federal (10.4%) or industry (2.6%) funding. CONCLUSIONS: RT-specific research hypotheses are a minority of phase II-III HNC trials, which mostly focus on incorporating ST in the definitive or recurrent/metastatic setting and have higher rates of industry funding. Radiation oncologist PI leadership and increased nonindustry funding access may ensure that RT-specific hypotheses are incorporated into trial design.