Programmed death-ligand 1 expression in pheochromocytoma

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

320

Programmed death-ligand 1 expression in pheochromocytoma Eur Urol Suppl 2017; 16(3);e552

Yasuhiro H., Tanaka T., Imai A., Hatakeyama S., Yoneyama T., Koie T., Ohyama C. Hirosaki University Graduate School of Medicine, Dept. of Urology, Hirosaki, Japan INTRODUCTION & OBJECTIVES: Programmed death ligand-1 (PD-L1), a key target molecule for immunotherapy, is frequently overexpressed in several neoplasms. In the present study, we examined PD-L1 expression in pheochromocytoma because very few reports on this subject are available. MATERIAL & METHODS: PD-L1 mRNA expression was compared across 184 pheochromocytoma, 492 prostate cancer, and 404 bladder cancer cases based on The Cancer Genome Atlas (TCGA). Furthermore, we enrolled 32 pheochromocytoma patients who were surgically treated at our hospital between June 2005 and February 2016. We conducted PD-L1 immunohistochemistry (IHC) using the SP142 assay. PD-L1 expression was scored at three diagnostic levels (0, 1, and 2). RESULTS: A comparison of PD-L1 mRNA expression based on the TCGA revealed that PD-L1 expression was significantly higher in pheochromocytoma than in bladder cancer and prostate cancer (p < 0.001). The SP142 assay of our 32 surgical pheochromocytoma cases revealed that the prevalence of a PDL1(+) expression (IHC score 1 or 2) in tumor-infiltrating immune cells (TICs) was 25% (eight patients) and that in tumor cells (TCs) was 28.1% (nine patients). The tumor diameter was significantly different between PD-L1(+) TIC patients (3.36 ± 0.35 cm) and PD-L1(−) TC patients (5.37 ± 0.50 cm, non-paired ttest: p = 0.044). In our cohort, there were two cases of malignant pheochromocytoma but none of them were PD-L1(+). CONCLUSIONS: PD-L1 expression is relatively higher in pheochromocytoma than that in bladder cancer and prostate cancer based on TCGA. The SP142 assay of our 32 surgical pheochromocytoma cases revealed that the tumor diameter in PD-L1(−) TICs cases was larger than that in PD-L1(+) cases. Further, there were no PD-L1(+) cases of malignant pheochromocytoma. These findings suggest that PD-L1 expression in pheochromocytoma is relatively common and that PDL1(+) expression in pheochromocytoma may not be associated with tumor aggressiveness.

Eur Urol Suppl 2017; 16(3);e552

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

320

Programmed death-ligand 1 expression in pheochromocytoma Eur Urol Suppl 2017; 16(3);e553

Eur Urol Suppl 2017; 16(3);e553

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

320

Programmed death-ligand 1 expression in pheochromocytoma Eur Urol Suppl 2017; 16(3);e554

Eur Urol Suppl 2017; 16(3);e554

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

320

Programmed death-ligand 1 expression in pheochromocytoma Eur Urol Suppl 2017; 16(3);e555

Eur Urol Suppl 2017; 16(3);e555

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

320

Programmed death-ligand 1 expression in pheochromocytoma Eur Urol Suppl 2017; 16(3);e556

Eur Urol Suppl 2017; 16(3);e556 Powered by TCPDF (www.tcpdf.org)