Global Cancer Trial Network Saves 3.34 Million Years of Life

Since the creation of SWOG—–a worldwide cancer clinical trials network, funded by the National Cancer Institute (NCI)––more than 200,000 adults have been enrolled in its trials, with approximately 20,000 individuals enrolled at any given time. The efforts of this network led to 14 new cancer drug approvals and more than 100 changes to the standards of care.

Following last year’s 60th anniversary, SWOG biostatistician Joseph Unger, PhD, sought to quantify its long-term impact. To his delight, he found 3.34 million years of life gained.

“The NCI’s investment in SWOG and our network has resulted in a significant benefit to the American public,” Dr Unger said in a press release. “A lot of people with cancer have lived longer because of the therapies tested in our publicly-funded trials. At the same time, the cost of this research is relatively low. So, with high impact and low cost, it’s a great value for taxpayers.”

For the study—–published in JAMA Oncology and presented at the 2017 ASCO annual meeting in Chicago—–Unger examined SWOG data between 1956 and 2016.

He identified 193 phase 3 randomized trials for analysis, all of which tested new drugs or procedures against current therapies to determine if they improved overall survival.

Of the 193 trials, 23 showed a statistically significant increase in overall survival due to novel treatments. A total of 12,361 patients were enrolled in the trial who were diagnosed with different cancer types such as breast, lung, prostate, and skin cancer, as well as leukemia, lymphoma, and myeloma.

A statistical model was devised using an analytical framework that assumed the new trial-proven treatments would become the standard of care, that the effects would last for 5 years, and all future patients diagnosed with those types of cancers would benefit from the treatment.

To estimate the number of patients the new treatment would apply to, Unger used the NCI’s Surveillance, Epidemiology, and End Results Program. He also estimated how long the patients were likely to live, and the period of post-treatment benefit.

Next, Unger calculated the cumulative life years gained from each trial and the number of gains from all 23 studies through the end of 2015.

In total, 3.34 million years of life were gained, even when the model was adjusted to account for patients who may not have received treatment. Unger also lowered the effect of new treatments from 5 years to 3. Despite this, the model still showed a benefit of at least 2 million years in nearly every simulation.

“This collection of data combining years of research shows a dramatic extension of life gained by participation in, or as a result of, clinical trials,” said Dr Jeff Abrams, associate director of Cancer Therapy Evaluation Program, NCI. “This provides a new metric for assessing the value of publicly supported cancer research.”

Unger also calculated the dollar return on investment from federal funding. He used federal budget data to create an inflation-adjusted estimate of $418 million in NCI funding to SWOG over its 60-year history in 2015 dollars, equating to $125 for each life year gained.

“Time is the most priceless gift we have, and the ability to give people with cancer more time with their loved ones is a major achievement,” said senior author Dr Charles Blanke, SWOG group chair. “To put the numbers in context, the most conservative estimate of 2 million years is equivalent of giving about 3 extra years of life to every one of the estimated 600,000 Americans expected to die of cancer this year. This is an exceptional benefit to come out of federally-funded cancer research.”