Validated diagnostic markers are key to the early detection and treatment of cancer. Moreover, if these biomarkers can be readily extracted and detected in bodily fluids, a simple, clinical diagnostic test can be developed that would be of extreme value to patients and physicians. For kidney cancer, investigators at Brigham and Women's Hospital (BWH) and Beth-Israel Deaconess Medical Center believe they have found such a biomarker. In a new study, the researchers showed that kidney-injury-molecule-1 (KIM-1)—which can be detected in the urine and blood—substantially helped distinguish between those who went on to develop kidney cancer from those who did not.
Findings from the new study were published recently in Clinical Cancer Research through a study titled “KIM-1 as a blood-based marker for early detection of kidney cancer: a prospective nested case-control study.”
While KIM-1 is generally present at low levels in healthy individuals, prior research showed that KIM-1 is an important and highly predictive marker for kidney injury. In the current study, the authors noted that they “aimed to test whether plasma KIM-1 could represent a means of detecting renal cell carcinoma (RCC) prior to clinical diagnosis.”
“Early detection of kidney cancer can be lifesaving. We can cure kidney cancer when we detect it at an early stage, but patients with advanced kidney cancer have a very high death rate,” explained co-senior study investigator Venkata Sabbisetti, Ph.D., a research faculty member in the BWH renal division. “However, kidney cancer is asymptomatic, and many patients present with advanced kidney cancer at the time of diagnosis. Our results suggest that with further refinement, KIM-1 has the potential to identify patients with early, curable kidney cancer.”
The research team measured KIM-1 concentrations in samples from patients enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC). The team compared KIM-1 levels from 190 participants who went on to develop RCC within the next five years to 190 matched participants (same age, body mass index, smoking status, etc.) who remained healthy. In samples with detectable levels of KIM-1, the average concentration was double in those who would develop kidney cancer.
Interestingly, the investigators reported that adding KIM-1 to a model for predicting kidney cancer risk approximately doubled the accuracy of that model. KIM-1 was substantially more sensitive for kidney cancer detection than prostate-specific antigen is for prostate cancer. However, given how much rarer RCC is, the researchers noted that KIM-1 should be measured along with another kidney disease-specific markers to be useful for early detection in the general population.
“We envision that KIM-1 will be useful in settings where the risk of kidney cancer is higher, such as patients undergoing abdominal CT scanning, where KIM-1 could be used to stratify risk of RCC,” the authors concluded. “This will be particularly important given the rise of routine CT scans and the strong association between the number of CT scans and number of nephrectomies performed at the regional level in the U.S., indicating a substantial burden of overdiagnosis.”
