BY PASSING current through surgically implanted electrodes, a team of
Australian and British surgeons may be able to offer hope for patients with
inoperable liver cancer.
When bowel cancer spreads to the liver, the tumours are often widely
dispersed. This can make it impossible to simply cut them out, because the
surgery is likely to damage major blood vessels or destroy so much healthy
tissue that liver failure results. In electrolysis, surgeons pass an electric
current through electrodes implanted in each tumour. The current creates local
changes in pH that kill cells over a very precise area without damaging
blood vessels.
Existing techniques for killing liver tumours with radio waves or liquid
nitrogen are less effective around big blood vessels, which damp down changes in
temperature. 鈥淭he big advantage of electrolysis is that blood vessels don鈥檛
appear to alter the effectiveness of the process,鈥� says Robert Padbury, a senior
surgeon at Flinders Medical Centre in Adelaide. Led by Guy Maddern, at the Queen
Elizabeth Hospital in Adelaide, and Ashley Dennison of Leicester General
Hospital, the team will show in an upcoming issue of Digestive Diseases
that electrolysis completely destroyed tumours implanted into rats鈥� livers. The
surgeons have also tested the technique in eight patients. Five of the patients
had the type of tumours that could be successfully removed by surgery. The team
applied electrolysis before removing the tumours. In each case, the tumour
tissue was destroyed.
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In the other patients, the team surgically removed as many of the tumours as
possible, and then used electrolysis to treat those that remained. These three
people have survived for between one and two years without showing any evidence
of more liver tumours. With standard treatment they might have expected to live
for no more than one year鈥攁lthough the researchers note that the study was
too small to draw firm conclusions.
鈥淲e may be being too optimistic,鈥� says Maddern, 鈥渂ut we鈥檙e happy that we have
controlled the disease in all the cases.鈥� A larger, five-year clinical trial is
about to begin.