Common medicines could lead to cancer patients’ deaths
Cancer patients are more likely to die of their disease if they use common antacids at the same time as immunotherapies a groundbreaking Australian study has found.
Flinders University researchers found bladder cancer patients using antacids called proton pump inhibitors (PPIs) were more likely to have their cancer progress and were less likely to respond to the breakthrough immunotherapy cancer treatment atezolizumab than those not using antacids.
The reason is the antacids change the patients gut bacteria researcher Dr Ashley Hopkins told News Corp.
The startling findings about the impact of the drugs goes some way to explaining the mystery about why one in three cancer patients respond so well to immunotherapies but others don't get the same benefit.
"The gut microbiota is linked to the immune system and regulating the immune systems natural anti-cancer responses," Dr Hopkins said.
Immunotherapies aim to boost the immune system to fight cancer but when antacids are used it impairs the ability for immunotherapies to work, he said.
"There is growing concern that an altered gut microbiome could negatively impact the efficacy of immune checkpoint inhibitors," researcher Dr Ashley Hopkins said.
Up to one in three cancer patients are using the antacid treatments to treat acid reflux, heartburn, and ulcers and Dr Hopkins said doctors should now be more cautious in prescribing them.
Examples of the antacids include Nexium, Zoton, Zopral, Losec, Maxor, Somac, Ozpan, Parbezol and Pariet.
The discovery was made by reviewing results of a clinical trial of immunotherapy atezolizumab in 429 people with bladder cancer.
The data review found patients using antacids had a 68 per cent greater risk of death, a 47 per cent greater risk of disease progression, and a 54 per cent lower response rate to the cancer treatment than those who did not use antacids.
However patients who received chemotherapy treatment for their cancer and who also used antacids did not see any significantly worse outcomes in their survival, progression-free survival, or the response rate to their cancer drugs.
"PPIs are overused, or inappropriately used, in patients with cancer by up to 50 per cent, seemingly from a perspective that they will cause no harm," said Hopkins.
"The findings from this study suggest that non-critical PPI use needs to be approached very cautiously, particularly when an immune checkpoint inhibitor is being used to treat urothelial cancer."
Previous work by Dr Hopkins has found the use of antibiotics can also impact on outcomes for cancer patients using immunotherapies.
This is because antibiotics also alter the gut bacteria.
However because antibiotics are used for a shorter period of time than antacids the effect on cancer outcomes was not as great, he said.
The researchers are now analysing other clinical trial data for other immunotherapies in other cancers to check whether antacid use impacted cancer outcomes.
It is the combination of the cancer treatment and the antacid that leads to poorer outcomes in cancer patients rather than the antacid alone.
News Corp is seeking comment from manufacturers of antacids medications.
Originally published as Common medicines could lead to cancer patients' deaths