Key clinical point: PD-L1 positive status in the tumor and negative status in the thrombus is linked to aggressive behavior in clear cell renal cell carcinoma.
Major finding: PD-L1 immunostaining was positive in at least one of the three samples of the main tumor in 22 of 39 advanced clear cell renal cell carcinomas. Cases that lost PD-L1 positivity in the thrombus (18 cases), were of higher grade (Fisher's exact test, P = 0.01) and higher AJCC pT category (Cochran Armitage, P = 0.02) than the cases that were positive both in tumor and thrombus (4 cases). A high variability in PD-L1 positivity was noted across three different areas of the main tumor tested. This variability should be kept in mind when selecting the tumor samples to be tested for determining immunotherapy.
Study details: An analysis of PD-L1 (SP142) expression in three different areas of the tumor and in two areas of the renal vein/caval thrombi in 39 advanced clear cell renal cell carcinomas.
Disclosures: The researchers reported no relevant financial disclosures.
Source: Lopez J et al. Annals of Diagnostic Pathology June 2018, Pages 89-93 https://doi.org/10.1016/j.anndiagpath.2018.03.007
Lopez J et al. Annals of Diagnostic Pathology June 2018, Pages 89-93 https://doi.org/10.1016/j.anndiagpath.2018.03.007