In articles appearing this weekend in News Corp media/AAP, a $4.8 million National Health and Medical Research Council grant has been provided by the Federal Government to conduct a study to determine if iv propofol is a safer anaesthetic choice for cancer surgery than the more typically used inhaled gases. Over 300,000 patients in Australia undergo cancer surgery with the use of anaesthetic each year.
The 5 year study of 5700 patients undergoing cancer surgery will be led by Prof. Bernhard Riedel from Melbourne’s Peter MacCallum Cancer Centre and will involve anaesthetists, surgeons, oncologists and research scientists from across the globe.
The study has been prompted by mounting evidence that cancer surgery patients sedated with inhaled gases have higher rates of cancer recurrence. A previous retrospective analysis of more than 7000 patients who had undergone cancer surgery, which was published in 2016, found that mortality was approximately 50% greater with volatile than with IV anaesthesia. Additionally, a Melbourne study conducted in mice found that those treated with gas anaesthetic had a much greater chance of their cancer returning than those sedated via an iv drip. It is believed that the properties of the volatile gases, being pro-inflammatory, pro-anogenic and immune-suppressant, may act like fuel to the fire of cancer.
According to Prof. Riedel, 80 percent of Australian and New Zealand anaesthetists still prefer to use the old “volatile” gases rather than the relatively new iv drug propofol. Although previous studies have shown a spike in cancer recurrence among patients anaesthetised with gas, these findings are not yet strong enough to change official guidelines. Prof. Riedel said that he has altered his clinical practise but that the greater community’s practise had not.
The study will also examine the use of iv lidocaine to determine if its use with propofol can reduce cancer progression after surgery.