Knight Cancer clinicians at Tuality/OHSU Cancer Center are the first in Oregon to offer a treatment option that will improve outcomes for patients with bladder cancer who cannot tolerate surgery or chemotherapy.
It involves giving carbogen gas, an inhaled mixture of oxygen and carbon dioxide, immediately before and during radiation therapy to minimize resistance due to tumor hypoxia.
“In bladder cancer, radiotherapy with concurrent chemotherapy is an accepted alternative to surgery. It is used to cure patients with bladder cancer without removing the bladder,” said Timur Mitin, M.D., Ph.D., medical director of the Tuality/OHSU Cancer Center.
But some patients can’t tolerate the chemotherapy. The carbogen gas regimen, combined with oral doses of the B vitamin nicotinamide, enables such patients to achieve high rates of survival without chemotherapy. The 5-year overall survival was 50% for radiotherapy plus carbogen and nicotinamide compared with 39% for radiotherapy alone in a clinical trial completed in the UK in 2010.
“In Europe and especially, England, it is the standard of care,” Mitin said. “In the U.S. not many people are using it.”
Mitin, an associate professor of radiation medicine in the OHSU School of Medicine and nationally recognized thought leader in the management of bladder cancer, was motivated to introduce the treatment after taking care of some prior patients with bladder cancer who couldn’t handle concurrent chemo.
“It felt bad knowing that there is high quality data showing that their outcomes would be better if we gave them carbogen and nicotinamide,” he said. “We weren’t set up to do it. We decided to change that and get the carbogen gas into our clinic.”
Tuality/OHSU Cancer Center might be the only clinic in the Pacific Northwest using carbogen and nicotinamide. Mitin knows of no other centers offering it.
The slow uptake in the U.S. probably reflects the predominance of radical cystectomy, surgical removal of the bladder, as a treatment for cancers that have invaded the muscular layer of the bladder wall. Many people with muscle-invasive bladder cancer who can’t tolerate surgery because of advanced age and/or other medical co-morbidities, receive no curative treatment. In one U.S. study, more than 25% of those aged 70-79 were treated with observation alone. Among those aged 80-89, nearly 40% were treated with observation alone.
That’s changing as demand for bladder preservation therapy increases. But radiation therapy remains an underused option for people with muscle-invasive bladder cancer who are unfit or unwilling to undergo surgical removal of the bladder.
“If there was greater recognition, greater realization that radiotherapy is a curative treatment option, I think we would see more of those patients,” Mitin said.