Share this Page:
Currently, the search for a reliable test to identify patients who are at risk of their kidney cancer coming back after nephrectomy has had limited success. A protein, called kidney injury molecule-1 (KIM-1), has been found in the blood of patients with kidney cancer. Studies have been testing KIM-1 as a potential biomarker to predict the recurrence of kidney cancer after nephrectomy.
Kidney tumours produce a lot of KIM-1, which enters the blood stream. Studies have shown that KIM-1 blood levels can be high for up to 5 years before kidney cancer is diagnosed. Researchers are looking at whether KIM-1 can be used as a potential biomarker to detect kidney cancer, to determine the risk of the kidney cancer coming back after surgery, and to give an indication of how the patient will respond to treatment.
Studies have assessed KIM-1 as a potential biomarker for many subtypes of kidney cancer, including clear cell and papillary renal cell carcinoma (RCC). Blood levels of KIM-1 before nephrectomy can predict the difference between a benign tumour and a cancerous tumour.
Other studies have shown that high levels of KIM-1 in the blood are associated with poor survival. Patients with high KIM-1 levels in their blood were more likely to have an aggressive cancer after nephrectomy.
Also, the presence of persistent KIM-1 following nephrectomy has been associated with disease recurrence and is an indiction of survival.
Blood samples from immunotherapy trials were analysed for KIM-1 levels. In one study, patients with high KIM-1 levels had a disease-free survival benefit with adjuvant immunotherapy compared with those who were treated with placebo.
The KIM-1 ratio is the percentage change in KIM-1 from baseline to 3 weeks. Studies have shown that the KIM-1 ratio at 3 weeks has been shown be able to predict response to immunotherapy in patients with advanced kidney cancer. Patients who were treated with the nivolumab plus ipilimumab combination and who had more than 30% rise in the KIM-1 ratio at 3 weeks had a significantly worse survival compared to patients who did not have more than 30% rise in KIM-1.
The KIM-1 ratio was a strong predictor of response to immunotherapy. Patients with a KIM-1 decrease at 3 weeks were exceptional responders to immunotherapy, and patients who did not have a good KIM-1 ratio at 3 weeks after one dose of nivolumab/ipilimumab did not have a good response to nivolumab/ipilimumab and had quite poor outcomes.
Perhaps by assessing the KIM-1 ratio, poor responders can be predicted and put on a more effective treatment ahead of time.
Currently KIM-1 is not in routine use as a biomarker to predict response to treatment. More work is needed to prove it’s effectiveness as a reliable biomarker.
