Pre-Nephrectomy Sorafenib Shrinks Renal Cancer Tumors
Administering sorafenib prior to nephrectomy for renal cell carcinoma (RCC) can reduce the size of the primary tumor with adding to the risk of surgery, according to researchers at the University of North Carolina at Chapel Hill.
“We found that primary kidney tumors responded to this therapy, shrinking up to 40% prior to surgery,” said principal investigator Kimryn Rathmell, MD, PhD, Assistant Professor of Medicine. “What this means for kidney cancer patients is that their surgery may be less extensive.”
Sorafenib is used to treat advanced-stage RCC as well as for a type of liver cancer. This agent prevents the growth of new blood vessels that enable tumor growth. Sorafenib is one member of a class of new targeted agents approved by the FDA for treating patients with metastatic kidney cancer.
The new study is the first to explore the possibility that pre-nephrectomy treatment might benefit patients who do not have metastatic disease.
In this prospective trial, 30 patients with clinical stage II or higher renal masses were selected based on their candidacy for nephrectomy. All patients underwent preoperative treatment with sorafenib, taking oral doses between four to eight weeks prior to surgery. The investigators monitored toxicities, surgical complications, and tumor responses. Of the 30 patients, 17 had localized disease and 13 had metastatic disease.
The primary tumor size decreased by a median of 9.6%, and the researchers observed radiographic evidence of loss of intratumoral enhancement, according to a report in the Journal of Clinical Oncology (2010; published online ahead of print).
Among the 28 patients evaluable for response, two had a partial response and 26 had stable disease. No patients progressed while on therapy, and the investigators observed no unexpected toxicities from sorafenib.
“The side effects were similar what we see with patients treated for late stage disease,” Dr. Rathmell told Renal & Urology News. “The side effects included hypertension, rashes, diarrhea and nausea. However, the side effects were mild and manageable. All the patients were able to get to surgery, and it [sorafenib] did not delay surgery for anyone. Before this approach can become standard of care it will require a much bigger study. Do we reduce recurrence with this approach? We just don't know that yet.”
“This study is a major contribution to the field, demonstrating that sorafenib is well-tolerated for pre-surgery use with no increase in the rates of complications or difficulties recovering from surgical removal of the kidney,” said study coauthor Matthew Nielsen, MD, Assistant Professor of Surgery.
“We are optimistic that this and future similar studies will ultimately allow us to offer individualized treatment strategies for patients with this common and dangerous disease.”
The investigators pointed out that their study findings are limited by the small sample size and the inclusion of patients with localized and metastatic disease. In addition, the varied histologies precluded a robust analysis of significant clinical endpoints, but they provide an early opportunity to explore how sorafenib might effect non-clear cell histology renal tumors.