Over the past 40 years, people in the US diagnosed with cancer gained 14 million years of additional life thanks to the results of cancer clinical trials conducted by the National Cancer Institute’s (NCI’s) publicly funded National Clinical Trials Network (NCTN), according to an analysis reported September 20, 2021, at the annual meeting of the European Society for Medical Oncology (ESMO).

The work, which analyzed the results and impact of 163 randomized, phase III studies published from 1980 through 2019, also found the published results of these NCTN studies have been cited more than 166,000 times, and that more than 80% of the studies influenced treatment guideline recommendations, demonstrating the profound scientific impact of these trials on cancer research and care over the decades.

The analysis was supported by the NCI, part of the National Institutes of Health (NIH), and was designed and led by the SWOG Cancer Research Network, which is part of the NCTN.

SWOG biostatistician and health services researcher Joseph Unger, PhD, of the Fred Hutchinson Cancer Research Center, led the analysis. “Our study illustrates the many ways in which federally sponsored trials have benefitted the lives of cancer patients and the scientific field,” Unger said. “There are many, many new commonly used treatments available to patients that may never have come into practice without NCTN trials.” 

SWOG Group Chair Dr. Charles Blanke is senior author on the abstract. “We have always known NCTN research profoundly benefited the lives of people affected by cancer,” Blanke said. “Dr. Unger’s work quantifies that benefit and demonstrates cooperative research is an incredibly low-cost, high-impact investment.” 

The NCTN comprises four groups that research cancers in adults (Alliance for Clinical Trials in Oncology, ECOG-ACRIN Cancer Research Group, NRG Oncology, and SWOG Cancer Research Network) and one group that performs research into childhood cancers (Children’s Oncology Group). These groups are the core of a network that runs clinical trials at more than 2,000 academic and community treatment sites across the U.S. and beyond, and they have conducted publicly funded research into effective new cancer treatments for more than half a century.

The current study looked at randomized, phase III treatment trials conducted by the adult NCTN groups. The authors identified 163 trials that had, from 1980 through 2019, reported statistically significant findings in favor of the experimental treatment for at least one clinical, time-dependent outcome. They then estimated life-year gains for the 128 trials that found either statistically significant improvement in overall survival time (91 trials) or a trend to improved overall survival (37 trials) for patients, and they mapped these gains onto the U.S. population of people with cancer. The analysis finds that through 2020 these trial results gave an additional 14.0 million years of life to people with cancer in the U.S. 

“Dr Unger’s findings are all the more important in this time of increasing costs of clinical research,” said Peter J. O’Dwyer, MD, group co-chair of the ECOG-ACRIN Cancer Research Group and a co-author of the work. “The return to the American people of government-funded investment in better cancer care has been remarkably solid – a huge impact.”  

And benefits from these NCTN trials are expected to continue to accrue.

“When we project estimates into the future, the estimates get larger very quickly,” Unger noted. In fact, the authors projected that by 2030, 23.4 million life years will have been gained based on the same set of trials.  

"The results from these cancer clinical trials reflect the experience of participants from both community and academic sites and show a dramatic gain in years of life," said Dr. Meg Mooney, associate director of NCI's Cancer Therapy Evaluation Program. "This work demonstrates the impact that cancer clinical trials conducted broadly on a national scale have on the field of cancer research and on people with cancer." 

Results from most of the studies were published in either the New England Journal of Medicine (49 trials) or the Journal of Clinical Oncology (72 trials). Those published results have been cited 166,711 times in later publications, an average of 64 citations per year for each trial, influencing subsequent cancer research and guidelines for treating patients with cancer. In fact, more than 80% of the trials were cited in cancer treatment guidelines in favor of recommended treatments. 

“When we think about reinvigorating the infrastructure of the U.S.,” Unger added, “it’s important to remember that the NCTN provides critical infrastructure to help prolong the lives of cancer patients.”  

The work was funded by the NIH/NCI through grants CA189974, CA180888, CA180819, CA180820, CA180821, and CA180868.

In addition to Unger, Blanke, and O’Dwyer, coauthors on the abstract include Michael LeBlanc, PhD, of SWOG Cancer Research Network; Monica M. Bertagnolli, MD, of Alliance for Clinical Trials in Oncology; Norman Wolmark, MD, of NRG Oncology; Walter J. Curran, MD, of GenesisCare; Mitchell D. Schnall, MD, PhD, of ECOG-ACRIN Cancer Research Group; Robert Mannel, MD, of NRG Oncology; Sumithra J. Mandrekar, PhD, of Alliance for Clinical Trials in Oncology; Joseph P. Costantino, DrPH, of NRG Oncology; Robert Gray, PhD, Fengmin Zhao, PhD, and Fangxin Hong, PhD, all of ECOG-ACRIN Cancer Research Group; and Mariama Bah, BA, and Riha Vaidya, PhD, both of SWOG Cancer Research Network.

Reference: ESMO Congress 2021 abstract 1503O - "Clinical and scientific impact of National Cancer Institute-sponsored clinical trial network group treatment trials," Annals of Oncology (2021) 32 (suppl_5): S1102-S1110. 10.1016/annonc/annonc711

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