BETHESDA, MD USA (UroToday.com) - Dr. Jose Karam opened his session by defining neoadjuvant therapy (NAT) as preoperative targeted therapy in the non-metastatic setting, as opposed to pseudo-NAT, which is given in the metastatic setting. He then went on to highlight the first study showing that some patients actually have tumor shrinkage after NAT. A second study highlighted the safety of NAT comparing 70 patients on preoperative bevacizumab to 103 who did not undergo NAT. All patients had metastases at the time of study. There were no significant Clavien grade 3 complication rate differences, but wound and fascial complications were statistically greater. This was not surprising given the known side effect profile of the drug. Regarding efficacy, he reviewed several prospective studies which showed between 0 and 46% response to a variety of drugs, although most studies had small cohorts. All studies treated mostly or exclusively clear cell RCC patients. In combining studies, TKI therapy showed greater response than bevacizumab, with sunitinib only having a 7% response rate. He also showed some data suggesting that unresectable patients may convert to resectable on TKI therapy. Again the cohorts were small, but up to 30-40% of patients may become resectable after NAT.
The next area where NAT has been studied is in determining if surgical procedure can be changed from radical to partial nephrectomy. Although most showed feasibility, these studies were fraught with confounding factors as most did not report how many patients may have had a partial pre-NAT. Only one prospective study of preoperative pazopanib from CCF and FCCC had conversion from planned radical to partial nephrectomy in 21 of 23 patients. There are limited data studying IVC thrombus shrinkage to reduce the extent of surgery. These studies are retrospective and showed poor efficacy in reducing the level of tumor thrombus.
He concluded by highlighting 2 cases from his institute’s axitinib NAT study who had disparate responses (vigorous vs no response). The patients on this trial had imaging as well as tissue and body fluid collection prior to, while on, and after therapy -- as well as in follow up. These samples will be mined for markers to predict response to therapy.
He closed by giving his opinions and stating that NAT for RCC patients should be used selectively and that identification of response predictors will be important going forward.
Presented by:
Jose A. Karam, MD
University of Texas MD Anderson Cancer Center
Reported by:
Philip Abbosh, MD, PhD* from the 2014 Winter Meeting of the Society of Urologic Oncology (SUO) "Defining Excellence in Urologic Oncology" - December 3 - 5, 2014 - Bethesda, MD USA
*Fox Chase Cancer Center, Philadelphia, PA USA