NEW YORK (Reuters Health) – The limited number of radiation therapy trials and lack of funding for such studies is “concerning,” given that radiation is a cornerstone of cancer management worldwide, researchers in China say.
“In this era of precision medicine, radiation oncologists are being left behind,” Dr. Jun Ma of Sun Yat-sen University Cancer Center in Guangzhou told Reuters Health by email.
Dr. Ma and colleagues downloaded records of all 243,758 interventional oncology studies registered at ClinicalTrials.gov from June 2007 to May 2017 and included 25,907 in a cross-sectional analysis.
Only 5.3% were radiation therapy trials, Dr. Ma and colleagues reported in JAMA Oncology, online May 17.
Radiation trials were less likely than other oncology studies to be registered before enrolling participants (55.7% vs 65.9%). They were also less likely to be blinded (3.3% vs. 11.3%), to involve multiple geographic regions (2.4% vs. 9.5%), or to be industry-sponsored (5.8% vs 43.4%).
By contrast, radiation trials were more likely than other cancer trials to be phase 2 to 3 (68.8% vs. 57.9%) and to have a data-monitoring committee (66.4% vs. 55.7%).
The number of radiotherapy trials sponsored by the U.S. National Institutes of Health decreased from 80 of 544 trials (14.7%) in 2007-2012 to 72 of 834 trials (8.6%) in 2012-2017.
Further, in that same period, the proportion of radiation trials involving more than 100 patients fell from 28.5% to 18.8%.
“Although advanced techniques have allowed radiation oncologists to give precise doses to different areas of the body – a strategy called ‘dose painting’ – the radiation fields, doses, or fractionations that are being used in the clinic are still mostly empiric,” Dr. Ma said. “It is like Jedis (in Star Wars movies) using lightsabers like knights used swords in the Middle Ages.”
“To change this situation, more clinical trials need to be conducted, and we also need a deeper understanding of radiation biology,” he said.
Dr. Kevin Du, a radiation oncologist at NYU Langone Health’s Perlmutter Cancer Center in New York City, told Reuters Health the study “shows that there is an enormous and under-explored clinical trial space (for radiotherapy) with the potential to improve patient outcomes and increase cancer cure rates.”
“There is a wealth of data that radiotherapy synergizes with new cancer treatments, including immunotherapies and other targeted therapies, and this should be (investigated in) clinical trials,” he said by email.
“In fact,” he added, “the American Society for Radiation Oncology recently issued a position statement advocating for the development of such combination trials (http://bit.ly/2kcEad3), and there is a real and immediate opportunity for industry and academic partnership on this important work.”
JAMA Oncol 2018.