The surgical team, led by Professor Guy Maddern from Adelaide University's Department of Surgery, developed the technique of inserting electrodes into the tumours and surrounding liver tissue, and then passing small electric currents through them.
This process, termed electrolysis, destroys tumour and liver tissue in much the same way as electrolysis destroys the follicles of unwanted hair. It affects much less normal liver tissue than surgery of a more conventional kind, in which tumours are cut from the liver.
The ten patients treated so far in the ongoing trial at the Queen Elizabeth Hospital had all been evaluated as unsuitable for conventional surgical treatment due to the extent of their tumours. Nine were patients whose colonic cancers had spread to the liver, while one was treated for cancer of the liver itself.
The average follow-up time for the patients was 9 months; the shortest time being 6 months and the longest 43 months. 8 of the 10 patients showed no evidence of residual tumour at the treatment site. 5 of these 8 patients had developed new areas of tumour spread, but 3 showed no evidence of tumour recurrence.
There has been considerable worldwide interest in the trials following the initial release of the story. The Department is continuing to treat new patients using the technique, but Dr Benjamin Teague, Research Registrar in the Department of Surgery, cautions that patients must meet a number of criteria to be considered for treatment.
"They must be fit for major surgery," said Dr Teague," which means having no significant medical conditions that would make them unsuitable for a general anaesthetic and abdominal surgery. They must also have no untreatable tumour outside the liver," he said.
If patients appear to meet the first two criteria, then further details, including scans of their tumours and reports are used to determine whether they meet the third criterion.
"Various kinds of scans can be used; MRI, ultrasound, PET or CT scans, but they need to show that the tumours that they have in the liver must be of a size, number and distribution that makes them suitable for electrolytic treatment," said Dr Teague.
If a patient's scans are promising, the team makes arrangements for further. These may include additional scans, a consultation and a preliminary 'keyhole' inspection, in which a small opening is made in the abdominal wall and a laparoscopic instrument used to make a visual inspection of the liver.
"If all of these procedures suggest that a patient is suitable for treatment, then we can perform the definitive procedure," said Dr Teague. "In many cases, the electrolysis is performed along with surgery to remove affected sections of the liver," he said.
Dr Teague cautions that, despite the promising trials, it is not yet possible to say whether the procedure is of long-term benefit.
"We can only determine that by evaluating the future progress of the patients who undergo this treatment, said Dr Teague. "However we do hope that by aiming to destroy the tumours in this way we may offer the possibility of a long-term cure to some patients."
Contact:
Professor Guy Maddern:
Department of Surgery, Queen Elizabeth Hospital
tel.+618 8222 6000 fax.+618 8222 6028 email. guy.maddern@adelaide.edu.au