Doctors have said there is a risk that weight loss jabs such as Ozempic and Mounjaro could raise the risk of being diagnosed with kidney cancer.
A new major study has suggested the risk of getting kidney cancer could be slightly elevated for those who are using the weight loss medication.
But medical experts say the risk of catching other obesity-related cancers is still lowered by using the jabs, meaning that for many, the benefits of taking the medication may still outweigh the risk.
The statistics have come as a result of the world's largest study of weight-loss drug users, with experts studying a total of 86,000 obese or overweight patients and tracking their progress for up to a decade.
See also: What are the most concerning effects of Ozempic?
Researchers found users had a 17 per cent lower risk of being diagnosed with a total of 16 cancers when taking weight loss medication.
This was compared to people of similar weight who did not take the drugs.
The risk of being diagnosed with endometrial cancers was reduced by 15 per cent and ovary cancer was reduced by 47 per cent.
But the findings revealed that patients who took weight loss medications were in fact a third more likely to be diagnosed with kidney cancer.
One of the experts in the study, Dr Hao Dai, a health data scientist at Indiana University who led the research, has since stressed that the study was observational and did not prove that weight loss drugs like Ozempic cause kidney cancer.
Kidney cancer is often called a 'silent' cancer because it can grow without causing obvious symptoms in its early stages.
The scientists in the study recruited 43,000 patients who were on weight loss drugs, and matched them to 43,000 control patients who were not put on the medication.
The participants had an average age of 52 and nearly seven in 10 were female.
None of those involved had a cancer diagnosis at the start of the study and half of the 43,000 patients given the drugs were being treated for type 2 diabetes, while half took them purely for weight loss.
Over an average of three years, researchers recorded 1,900 cases of 16 different cancers in the group.
For kidney cancer specifically, there were 83 cases recorded among patients on GLP-1 drugs compared to 58 cases in the control group.
Researchers said they plan to keep tracking the patients for longer to confirm the data and will be reliving further into analysing the results to look for trends.
Researcher Dr Dai continued: “We need to do another observational study to confirm that these drugs increase the risk. But from my point of view, it might be that the drugs raise the risk of some types of kidney cancer. We don't know, however, and need to do more research.”
Other doctors have also said these results do not provide a stable link to an increase in kidney cancer just yet.
Dr Neil Iyengar, an onoclogist at Memorial Sloan Kettering Cancer Center in New York who was not involved in the latest study, told the Daily Mail that he 'didn't fully buy' the potential link with kidney cancers, highlighting that other research has shown GLP-1 drugs actually protect against kidney cancer.
He said: “The issue is that we're still at a very early stage gathering GLP-1 data which will give us mixed result.
“We do need more data to address this potential kidney cancer issue, however.'
The findings were laid bare at the American Clinical Society of Oncology's annual conference in Chicago, Illinois, the largest cancer conference in the world.
