Paired primary and metastatic samples from 45 ccRCC patients were included in this analysis. Only areas with predominant and highest Fuhrman nuclear grade (FNG) were selected. c-Met expression was evaluated by IHC using an anti-Met monoclonal antibody (MET4 Ab, VARI). PD-L1 expression was assessed by IHC. c-Met expression (average c-Met CS) between paired primary and metastatic samples were compared. Associations of c-Met expression with PD-L1 expression (+/-) and other clinical features were assessed as well.
The final cohort included 45 primary ccRCCs and 54 corresponding metastases. c-Met expression was higher in metastatic sites compared to primary (c-Met CS: 55 vs. 28, p=0.0003) and was numerically-greater in PD-L1+ vs. PD-L1- tumors. Higher c-Met expression was associated with higher FNG and T-stage in both primary and metastatic sites, as shown in the table below.
In summary, higher c-Met expression was demonstrated in metastases compared to paired primary tumors in our cohort of ccRCC. Although the observation that higher c-Met expression was shown in PD-L1+ tumors, it still requires further investigation.
Presented By: Aly-Khan A. Lalani, Dana-Farber Cancer Institute, Boston, MA
Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre
at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 - Chicago, Illinois, USA