Using tiny but powerful bursts of electricity to make holes in pancreatic cancer cells may improve survival rates for some patients, new research suggests.
Using zaps of electricity in certain patients can "nearly double the survival rate with the best new chemotherapy and chemo-radiotherapy," said study authour Dr. Robert Martin II, director of surgical oncology at the University of Louisville.
Surgeons can use the short electrical bursts to kill cancerous cells in delicate areas without destroying noncancerous tissue nearby, such as nerves. The electrical bursts make permanent holes, or pores, in the cells, eventually killing them, the researchers said.
The procedure is called irreversible electroporation, or IRE.
However, Martin said the next step for his team is to test the treatment in a clinical trial with a larger group of patients.
The people in the current study all had a pancreatic tumour that had extended into nearby organs, making complete surgical removal impossible. The zapping technique is intended to corral the cancer cells and extend the patient's survival.
One pancreatic cancer expert called the approach another potential treatment opportunity.
"The goal is to eliminate as many cancer cells as possible that linger after other treatment types, like surgery, chemotherapy or chemo radiation," said Lynn Matrisian, vice president of scientific and medical affairs at the Pancreatic Cancer Action Network. "The more opportunities presented to pancreatic cancer patients, the more hope for improved outcomes."
Such opportunities are critical for those with pancreatic cancer because the disease is among the deadliest of all cancers. By 2020, this cancer is expected to be second only to lung cancer as a cause of cancer-related death, according to the Pancreatic Cancer Action Network.
All of the 200 adults with stage 3 pancreatic cancer included in the current study underwent electrical IRE treatment after completing chemotherapy.
About half of the patients in the study experienced complications. But the side effects related to IRE were minimal, according to Martin. Any side effects were "directly related to the surgical procedure" required to make the tumor area accessible, he said.
The average survival was two years, the study found. The study authors followed some patients for as long as seven years.
The improvement in survival with the procedure is good news for patients whose pancreatic cancer cells haven't yet escaped the initial tumor, Martin said. Even some patients with an earlier-stage cancer might be good candidates for it if they can't have the usual surgery to remove a tumor, he said.
Unfortunately, patients whose cancerous cells have escaped the original tumor probably won't benefit from the procedure, said Martin. "For stage 4 cancers, we do not recommend IRE since it is a local therapy," he said. Cancers that have traveled beyond their original location require a body-wide treatment.
Matrisian agreed that the procedure would likely be best suited for patients with advanced cancer that hasn't spread elsewhere. That's a substantial number of patients with the disease, about 30 percent of pancreatic cancer cases, she said.
"There is currently a lack of consensus in the field on how to treat patients with [this stage of pancreatic cancer], underscoring the importance of novel and effective approaches to improve patient outcomes," she said.
The electric IRE approach also has been used to treat other types of cancer, including prostate cancer, said Matrisian, and other studies are also in progress in pancreatic cancer patients.
Matrisian added that her organisation recommends "that all patients consider clinical trials when exploring treatment options."
Results of the current study were published in Annals of Surgery.