Electric Pulses May Help in Pancreatic Cancer
A minimally invasive procedure that uses electrical pulses to target cancer cells may help make surgery an option for unresectable, locally advanced pancreatic cancer patients, researchers said here.
In a small trial, about a quarter of patients who had percutaneous irreversible electroporation (IRE) had their disease downstaged and were able to have surgery, Govindarajan Narayanan, MD, of the University of Miami, and colleagues reported during a press briefing at the Society of Interventional Radiology meeting here.
“This could be a new [therapeutic] option, with the potential to downstage patients to surgery,” Narayanan said.
Patients with locally advanced disease aren’t often candidates for surgery because their tumors are surrounded by pancreatic blood vessels. Chemoradiation can convert some patients to candidates for resection, but not all.
Clinicians also have tried ablative therapies, but these also run the risk of collateral damage to blood vessels, Narayanan explained.
Instead, irreversible electroporation delivers high-voltage, low-energy direct current pulses to tumor cells via CT-guided electrode needles. The bursts of energy perforate individual cells, ultimately leading to apoptosis, while sparing surrounding blood vessels.
PANCREATIC CANCER FACTS
- An estimated 44,030 Americans will be diagnosed with pancreatic cancer in the U.S., and over 37,660 will die from the disease.
- Pancreatic cancer is one of the few cancers for which survival has not improved substantially over nearly 40 years.
- Pancreatic cancer is the 4th leading cause of cancer-related death in the United States.
- Pancreatic cancer has the highest mortality rate of all major cancers. 94% of pancreatic cancer patients will die within five years of diagnosis – only 6% will survive more than five years. 74% of patients die within the first year of diagnosis.
- The average life expectancy after diagnosis with metastatic disease is just three to six months.
- Few risk factors for developing pancreatic cancer are defined. Family history of the disease, smoking, age, and diabetes are risk factors.
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- Source for statistics: American Cancer Society: Cancer Facts & Figures 2011 and NCI Funded Research Portfolio
The device used in this study, the NanoKnife, is FDA-approved for use in soft tissue. Use in organs is off-label, Narayanan noted, though it has been investigated in primary and metastatic liver cancer.
For their study, Narayanan and colleagues reviewed the records of eight pancreatic cancer patients who weren’t eligible for surgery and had irreversible electroporation at their facility between December 2010 and September 2011.
The median patient age was 53, median time from diagnosis to irreversible electroporation was about nine months, and median tumor size was 8.8 cm.
All patients had had prior chemotherapy and seven had had prior radiation.
Overall, two patients became candidates for surgery, and were resected 4 and 5 months after the electrical procedure, the researchers said. Both patients had margin-negative resections and one had a pathologic complete response.