Targeted therapy has an association with improved progression-free survival and overall survival benefits, although it is rarely associated with a long-term response. The study evaluated the National Cancer Database (NCDB) and identified patients between 2006 and 2012, who had metastatic clear cell RCC, who received cytoreductive nephrectomy and targeted therapy. The study team specifically excluded patients who had brain metastases at diagnosing, as they believed that these patients were predisposed to have worse outcomes due to this location. The study team also categorized patients into four groups: (1) early treatment group: < 2 months, after surgery, (2) moderately delayed: 2-4 months post-surgery, (3) delayed: 4-6 months, and (4) late, > 6 months, after surgery.
The study identified 2,716 patients that met their criteria. Median time to initiation of targeted therapy was about 2.1 months, with 46% of patients receiving targeted therapy within the early time point, 40% in the moderately delayed time point, and 14% in the delayed and late. When evaluating patient demographic information, the study team found that the lack of insurance coverage and surgery on metastatic sites were the main predictor of delayed targeted therapy (p=0.03). Median overall survival for patients was 20.6 months. Using a Kaplan Meier analysis, no differences were found between initiation of targeted therapy in the different time groups.
Using a cox regression model, the study tried to identify predictors of mortality. They found that a Charlson Comorbidity Index > 2, being of African American descent, having Medicaid insurance, and being treated at a community center were all significant predictors of increased rate of mortality. They found no differences in mortality between the early versus moderately delayed, delayed, or late groups.
In conclusion, delaying targeted therapy in metastatic RCC was not associated with worse overall survival. This finding is in stark contrast to other analysis on other types of cancers, where delaying chemotherapy is often associated with worse outcomes. The study believes that this is possibly due to a difference in biology between the different types of cancer.
Presented by: Solomon Woldu
Co-Authors: Justin Matulay, New York, NY, Timothy Clinton, Nirmish Singla, Yuval Freifeld, Oner Sanli, Laura-Maria Krabbe, Ryan Hutchinson, Yair Lotan, Hans Hammers, Raquibul Hannan, James Brugarolas, Aditya Bagrodia, Vitaly Margulis, Dallas, TX
Written by: Anthony Warner, AS, Department of Urology, University of California-Irvine, medical writer for UroToday.com at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA