One IMRT advocate said the results provide him with a “weapon” to use in arguing with insurance companies over his treatment decisions.
The researchers who conducted the study, however, acknowledge they reached a “unique, and controversial, finding.” Led by Dr. Beth Beadle, the researchers examined Medicare records from between 1999 and 2007 and compared the survival rates for 3,172 head-and-neck-cancer patients for those treated with IMRT and those receiving conventional radiation treatments.
Using a “cause-specific survival” measurement, which calculated the chances of dying from head and neck cancer after 40 months, Beadle and colleagues found a 38.9% rate for patients treated with IMRT and a 18.9% rate for those receiving traditional treatment.
Rather than declaring they had found iron-clad proof of IMRT's superiority, they cautioned that “the analysis and conclusions here should be considered hypothesis-generating.”
The study was published this month in Cancer, a journal of the American Cancer Society.
At the very least, its findings start off 2014 with a bit of positive news for IMRT, which was the subject of much negative press in 2013. Last June, a report
in the Annals of Internal Medicine found that men at low risk of dying from prostate cancer but at high risk of dying of other causes were being treated with IMRT and other high-cost methods “unnecessarily at substantial personal and societal cost.”
In August, the U.S. Government Accountability Office
issued a report
finding a massive increase between 2006 and 2010 in IMRT conducted at facilities owned by self-referring physicians and a decrease in IMRT referrals among doctors who didn't own such facilities. A similar report
was published by the New England Journal of Medicine in October, and it widened a rift between the radiation oncologists who funded the study and the urologists who came under fire because of its findings.
“It's certainly an interesting report,” said Dr. Bhadrasain Vikram, chief of the clinical oncology branch of the National Cancer Institute. “I hope they are right—that it improves outcomes—but we still need to do a randomized trial.”
The authors cited American Cancer Society estimates
that 54,000 patients in the U.S. were diagnosed with head and neck cancers last year and that head and neck cancers caused 12,000 deaths. Head and neck cancers are becoming less related to smoking and more associated with viral causes such as the human papillomavirus, or HPV, and HPV-positive cancers respond better
to chemotherapy and radiation. Also, positive emission tomography, or PET, scans—which use radioactive tracers to detect disease—have helped better identify patients who could benefit from IMRT.
Vikram said a shortcoming of the MD Anderson retrospective study was that it didn't include data on patients' HPV status, which the study's source—the Surveillance, Epidemiology, and End Results (or SEER) Medicare database—doesn't provide. Another weakness was that the study didn't provide information on whether patients had received a PET scan, which Vikram said should be available through SEER, a National Cancer Institute database which includes tumor registries from 17 regions accounting for 25% of the U.S. population.
Having this data would help explain whether the findings were a result of IMRT's effectiveness or were the reflection of a selection bias. In their report, the MD Anderson researchers noted that they looked for patients who had begun treatment within four to six months of diagnosis, and whose tumor was pathologically confirmed—and not diagnosed at death or autopsy.
Of this cohort, 1,056 (32.1%) were treated with IMRT and 2,116 (66.7%) received other therapies. A total of 888 patients died from head and neck cancers. After adjusting for factors such as age, income, race, and marital status, the IMRT patients had a cause-specific survival rate of 38.9%, and the non-IMRT patients had a 18.9% rate.
“From a scientific perspective, the findings support the use of IMRT and suggests we can provide excellent care while optimizing cancer outcomes and reducing toxicities,” Beadle, an assistant professor in the MD Anderson radiation oncology division, said in a news release
. “At a more global level, with concerns about healthcare financing and resource allocation, IMRT is more expensive than conventional radiation therapy, but the data suggest it's worth it.”
Vikram noted that the evaluation of cost effectiveness is more the purview of the CMS and the Agency for Healthcare Research and Quality, while National Institutes of Health's focus is clinical effectiveness.
On that score, he said, “I'm still not convinced the effectiveness has been shown.”
But Dr. Daniel Haraf, medical director of radiation oncology at University of Chicago Medicine, argues otherwise.
“There is always a question with new technology: Doctors and insurers wonder whether newer, more expensive technology is any better,” said Haraf, an early adopter of IMRT who specializes in cancers of the lungs, esophagus, head and neck. “I think this paper provides evidence to help answer that question for head and neck cancer.”
He agreed that a randomized control trial would be the “gold standard,” but also wondered whether such a test would be ethical.
“You can't intentionally give someone something you know is worse,” Haraf said, explaining that the benefits of a trial's experimental and standard “arms” have to be seen as being near equal.
Haraf said he hoped this report will have a positive impact on the debate over IMRT's cost and effectiveness.
“As healthcare dollars get to be more and more precious, I find myself spending more and more time with insurance companies defending everything I do,” Haraf said, adding that this report now gives him a “weapon” to use in these arguments.
Dr. Austin King, an otolaryngologist and head and neck surgeon based in Abilene, Texas, acknowledged that IMRT gives doctors better control of radiation doses and patients have fewer side effects. But he questioned whether head and neck cancer patients were the best beneficiaries of this treatment.
“I am still unconvinced that this will lead to significant improvement in cure rates for head and neck cancer since many people die of spread of the disease to the lymph nodes in the neck rather than the primary tumor,” said King, president-elect of the Texas Medical Association. “After visiting with my radiation colleagues here, they believe one of the main benefits is in treatment of prostate cancer since they can minimize the effects on the surrounding tissue.”Follow Andis Robeznieks on Twitter: @MHARobeznieks