Kidney cancer is one of the 10 most common cancers for both men and women (although for women, it’s number 10, for men, number 7). More than 60,000 Americans (2/3 are men) are diagnosed with kidney cancer every year, and 14,000 (again, 2/3 are men) will die. The good news is that, caught early, about 80% of patients survive. The bad news is that catching it early is a challenge. “The most common way that we find kidney cancer is as an incidental, fortuitous finding when someone has a CT or MRI scan,” said Evan D.Kharasch, the Russell D. and Mary B. Shelden Professor of Anesthesiology at Washington University School of Medicine in St. Louis. “It’s not affordable to use such scans as a screening method, so our goal has been to develop a urine test to identify kidney cancer early.” And it seems that Kharasch and his team did just that.
They analyzed urine samples from more than 700 patients who were going in to have abdominal CT scans having nothing to do with kidney cancer. They measured the levels of two proteins in the urine—aquaporin-1 (AQP1) and perlipin-2 (PLIN2). “Each protein, or biomarker, individually pointed to patients who were likely to have kidney cancer, but the two together were more sensitive and specific than either by itself,” says Jeremiah J. Morrissey, professor of anesthesiology and co-author with Kharasch of a study published in the journal JAMA Oncology. When they put the two biomarkers together, they correctly identified the patients with kidney cancer and didn’t haves any false positives.
Now here’s the best part: “[In] addition to being able to detect kidney cancer early, another advantage of using these biomarkers may be to show who doesn’t have the disease.”
“By and large, patients don’t know they have kidney cancer until they get symptoms, such a blood in the urine, a lump or pain in the side or the abdomen, swelling in the ankles, or extreme fatigue,” Morrissey says. When a patient presents with any of these symptoms, the doctor will probably order a CT scan. But by then, it’s often too late.
Plus, “a CT scan can only tell you whether there is a mass in the kidney, not whether it’s cancer,” Kharasch says. “Currently, the only way to know for sure is to have surgery, and unfortunately, 10 to 15 percent of kidneys removed surgically turn out not to be cancerous.”
Morrissey and Kharasch are hard at work trying to develop a simple screening test for kidney cancer.
