Zap those tumours away!

Author:  Charley Wang

Institution:  University of Toronto
Date:  August 2007

It's not a magic wand, but it could be the next best thing. Researchers at Virginia Tech and the University of California at Berkeley recently developed a new way to treat cancer: with a zap. The treatment uses a process called electroporation to selectively eliminate tumours with minimal surgery.

True to its name, electroporation uses an electric field to open small pores in cell membranes. If done in moderation, the pores will be quickly resealed by the cell's repair mechanisms. This is called reversible electroporation, and it has been used for decades in gene transfer and drug intake.

On the other hand, irreversible electroporation (IRE) arises from prolonged exposure to an electric field. It is the cellular equivalent to being struck by lightning. The heat alone is a big problem: when left active, electrodes can cause irreversible thermal damage to everything in the vicinity. For that reason, IRE has been conscientiously avoided in vivo, until now.

First, Dr. Rubinsky and Dr. Onik tested the limits of IRE. In this earlier study, they showed that cells could be killed with low power electric fields that don't pose a thermal threat. In the present study, they aimed to verify the feasibility of IRE in a large animal.

Irreversible electroporation was performed on fourteen female pigs to test the effects of IRE on a target area and the surrounding tissue. The results were immensely positive. To summarize, the target area was destroyed with no collateral damage.

According to Dr. Onik, "[T]his is about as good as it gets. We've been using other techniques for a long time. This provides significant improvements over other treatments."

IRE has been approved by the US Food and Drug Administration and is undergoing human clinical trials this summer.

- By Charley Wang.