Scientists have discovered that a marker in the blood could help predict the risk that a person will develop kidney cancer, according to research published in the journal Clinical Cancer Research.

Supported by Cancer Research UK, the IARC and the NIH, the work used samples taken as part of the EPIC* study to examine the blood of 190 people who went on to develop kidney cancer, compared to 190 controls who did not.

“This work is a big step forward; KIM-1 is the only blood biomarker shown prospectively to distinguish between people at high and low risk of kidney cancer.” – Dr David Muller, Cancer Research UK-funded co-first author.

They found that measuring levels of a protein molecule in the blood, called KIM-1, could indicate whether a person was more likely to develop kidney cancer over the following 5 years.

The data also showed that the greater the concentration of KIM-1, the higher their risk** of developing kidney cancer.

In people with kidney cancer, KIM-1 levels were also found to be linked with poor survival, as those with the highest levels in their blood were less likely to survive.

In the future, the scientists think that testing for blood KIM-1 levels could be used alongside imaging to confirm suspicions of kidney cancer, or help to rule out the disease.

Dr David Muller, Cancer Research UK-funded co-first author based at Imperial College London, said: “This work is a big step forward; KIM-1 is the only blood biomarker shown prospectively to distinguish between people at high and low risk of kidney cancer. But there’s a lot more work to do before we could envisage this in the clinic.

“The next steps are to look more closely at whether KIM-1 levels can help detect tumours that have a good prognosis, so those at an early stage, and to find out if it could be used as a tool to track whether a patient’s treatment is working.”

Kidney cancer is the 7th most common cancer in the UK and cases are on the rise. When diagnosed at its earliest stage, more than 8 in 10 people will survive their disease for 5 years or more. More than 4 in 10 cases in England are diagnosed at a late stage, however, and just 1 in 10 people survive kidney cancer when diagnosed at the latest stage.

Diagnosing the disease earlier therefore has the potential to boost survival, but the majority of early-stage tumours do not present symptoms and many cases are picked up incidentally during imaging for a range of other health conditions.

Professor Charles Swanton, Cancer Research UK’s Chief Clinician, said: “The potential of blood tests for the detection and monitoring of cancers is becoming increasingly apparent, and this work offers further evidence that they could become powerful tools in the clinic.

“There is a pressing need to shift kidney cancer diagnoses towards earlier stages, when treatment is more likely to be successful, and this promising research is progress towards that goal. This work is still in early stages, so prospective studies of larger populations are needed before this approach could be widely adopted.”

Dr Rupal Bhatt, NIH-funded senior author based at Harvard Medical School, said: “It’s now crucial to understand more about how KIM-1 could be incorporated into patients’ treatment.

“We’re excited about progressing this important work further and testing whether KIM-1 levels could help identify patients who may benefit from additional treatment after surgery, and therefore potentially improve their outlook.