News article

29 May, 2018

Xu Liu, MD1; Yuan Zhang, MD1; Ling-Long Tang, MD1; et al

Source of this article: JAMA network

Key Points

Question  How does a climate of expanding targeted and immune therapies but declining funding from the National Institutes of Health affect the conduct of radiotherapy trials compared with other oncological trials?

Findings  In a cross-sectional analysis of 25 907 interventional oncological trials registered in from 2007 to 2017, only 1378 (5.3%) were radiotherapy trials. Sponsorship or funding for radiotherapy trials was significantly less than that for other oncological studies, and the proportion of radiotherapy trials with a sample size of more than 100 patients has decreased in the past decade.

Meaning  The decline of radiotherapy trials warrants discussion and collaboration among oncologists, funding agencies, industry leaders, and other concerned parties across multiple geographic regions.


Importance  Modern precision radiotherapy is an innovative and effective treatment of cancer, yet it is unclear how radiotherapy trials are affected by expanding targeted and immune therapies and declining National Institutes of Health funding.

Objective  To analyze and compare the characteristics of radiotherapy trials with other oncological trials registered on

Design, Setting, and Participants  This is a cross-sectional analysis of trials registered on between June 1, 2007, and May 8, 2017. Records of all 243 758 clinical studies registered by May 8, 2017, were downloaded, but only 25 907 interventional oncological trials registered between June 1, 2007, and May 8, 2017, and whose primary purpose was “treatment” were included in the final analysis. Trials were categorized according to cancer type and other registration information.

Main Outcomes and Measures  Characteristics of radiotherapy trials were compared with characteristics of other oncological trials. Chronological shifts in radiotherapy trials were also analyzed.

Results  Of the 25 907 trials selected, 1378 (5.3%) were radiotherapy trials and 24 529 (94.7%) were other oncological studies. The number of radiotherapy trials increased gradually from 94 (June 1, 2007, through May 31, 2008) to 192 (June 1, 2015, through May 31, 2016). Radiotherapy trials were less likely than other oncological studies to be registered before participant enrollment (763 of 1370 [55.7%] vs 16 105 of 24 434 [65.9%]; P P P P P P P P 

Conclusions and Relevance  The limited number of and the scarcity of funding for radiotherapy trials is concerning given the integral role of radiotherapy in the clinical management of patients with cancer worldwide. A multidisciplinary collaboration to promote and fund more radiotherapy research is warranted.

« Go back