The study, led by researchers at the Duke Cancer Institute, is the first and largest to compare the effectiveness of treatments used for metastatic non-clear cell kidney cancers, a group of malignancies that account for about 20 percent of kidney cancers. “We have had very little evidence to guide clinical decision-making and drug choice for patients with non-clear cell renal cancer,” said Andrew Armstrong, M.D., co-director of the genitourinary oncology research program at Duke Cancer Institute and lead author of a study presented at the American Society of Clinical Oncology annual meeting. “These cancers are actually very different diseases, with different genetics, so we cannot have a one-size-fits all approach.”
In their study of 108 patients, Armstrong and colleagues focused on three forms of non-clear cell kidney cancers: metastatic papillary, chromophobe or unclassified. The patients were randomly assigned to receive one of the two approved treatments that are typically used, everolimus or sunitinib, until their tumors progressed.
The researchers found that sunitinib was superior overall compared with everolimus at prolonging the amount of time before tumors regrew, but at a higher rate of severe toxicity. Sunitinib was more effective for papillary-type kidney cancers and for better prognosis patients. Patients with chromophobe and poor-risk tumors treated with everolimus had a longer median progression free survival than patients treated with sunitinib.
“These drugs have different mechanisms of action, so it makes sense that they would have different response rates for these tumors, which are essentially different diseases genetically,” Armstrong said. “This information provides physicians sound data to guide treatment for their patients based on the kind of cancer identified.”
More than 100 study patients also donated tumor tissue, establishing the largest repository of non-clear cell kidney cancer tissue to aid development of new drugs and biomarkers for the disease.