Irreversible Electroporation Boosts Soft-Tissue Cancer Survival, but with Significant Morbidity and Cost

July 2016, Vol 7, No 6

A new article by a New York surgical team confirms that there is a survival benefit from an emerging therapy for difficult-to-treat soft-tissue tumors, but that it is not without a steep price for some patients (Kluger MD, et al. Ann Surg Oncol. 2016;23:1736-1743).

Michael D. Kluger, MD, MPH, Assistant Professor of Gastrointestinal and Endocrine Surgery, New York-Presby­terian Hospital, Columbia University, New York, NY, and colleagues summarized the results for their first 50 patients with T4 pancreatic cancer who received treatment with irreversible electroporation (IRE; NanoKnife; AngioDynamics). This is the largest single-institution series ever published. Overall, 6 (12%) patients died in the first 90 days after the procedure, and another 10 (20%) experienced other major complications.

An earlier article examined the outcomes from 200 patients with stage III (T4) pancreatic cancer who received treatment at 6 centers (Martin RCG II, et al. Ann Surg. 2015;262:486-494). There was a 37% complication rate. However, there are some inconsistencies in the article, which makes it more difficult to interpret the data. For example, a table in the article on complications lists 2 grade 5 complications (ie, death), but the investigators state in the text that there were 3 deaths. The researchers reported a 3% local recurrence rate at a median follow-up of 29 months. The median overall survival was 24.9 months.

“We feel in our center, based on our results, that there is benefit from the treatment, either used alone or in combination with resection or formal pancreatectomy,” Dr Kluger said in a telephone interview. “So I agree with everyone about that, but we need to parse out what the survival benefit is, because it is also coming at a time when we have more effective chemotherapy than we have ever had for pancreatic cancer. I see the NanoKnife as an adjunct treatment in the most difficult cases that have the highest complication rate in general.”

IRE is used for the curative-intent treatment of patients with advanced-­stage pancreatic cancer, as well as for those with renal, liver, prostate, or lung cancer. A very high current is passed between probes across the tumor tissue for brief bursts of approximately 90 millionths of a second, interspersed with 2- to 5-second breaks, and repeated up to 180 times. This punches tiny holes in the cell walls and leads to cell death, but not to tissue necrosis.

The NanoKnife is the only device on the market for IRE. It costs between $250,000 and $300,000, plus approximately $2000 for each probe, according to Robert C. G. Martin, II, MD, PhD, University of Louisville School of Medicine, KY, in a question and answer section at the end of his article. Dr Martin reported a total hospital charge per procedure of between $75,000 and $80,000.

Dr Kluger and colleagues reported that 5 of the 6 patients who died had IRE ablation of the primary tumor, whereas 1 patient had IRE of only the tumor margins after pancreatectomy. Another 5 patients had grade 3 or 4 complications. The median overall survival after IRE was 7.71 months in the primary tumor IRE group and >8.7 months in the margin IRE group. However, as Dr Kluger told Value-Based Cancer Care, these patients were followed for only 33% of the time that the patients in the study by Dr Martin and colleagues were followed. Some of the patients continued receiving chemotherapy after IRE treatment.

Dr Kluger and colleagues are now mostly performing IRE for margin extension rather than for unresectable tumors. The researchers also use IRE for some cases of liver metastases from colo­rectal cancer. Other centers use IRE for renal, liver, prostate, and lung cancers.

Related Articles