Melissa Stanton

Monoclonal antibodies that target the programmed death-1 (PD-1)-programmed death ligand-1 (PD-L1) axis have antitumor activity against multiple cancers. The presence of sarcomatoid differentiation in renal cell carcinoma (RCC) is associated with resistance to targeted therapy and poor responses to IL2 immunotherapy. Given the aggressive nature of RCC with sarcomatoid differentiation and the exclusion of sarcomatoid histology from metastatic RCC clinical trials, less is understood regarding selection of therapies. Here, we characterized the PD-1/PD-L1 axis in RCC with sarcomatoid differentiation. We directly compared two PD-L1 antibodies and found concordance of PD-L1 positivity in 89% of tested RCCs with sarcomatoid differentiation. Coexpression of PD-L1 on neoplastic cells and the presence of PD-1-positive tumor-infiltrating lymphocytes were identified in 50% (13 of 26) of RCCs with sarcomatoid differentiation. In contrast, only 1 of 29 clear cell RCCs (3%) had concurrent expression of PD-L1 and PD-1 (P = 0.002). Our study suggests that RCC with sarcomatoid differentiation may express PD-1/PD-L1 at a higher percentage than RCC without sarcomatoid differentiation, and patients with these tumors may be good candidates for treatment with anti-PD-1/PD-L1 therapies.

CONTEXT: Urothelial tumors are rare in young patients. Because of their rarity, the natural history of the disease in young patients remains poorly understood. OBJECTIVE: To understand the pathologic and clinical features of urothelial tumors of the urinary bladder in young patients. DESIGN: We identified 59 young patients with urothelial tumors of the urinary bladder treated at our institution and analyzed the tumors' pathologic features and the patients' clinical outcomes. RESULTS: All patients were 30 years or younger, with a mean age of 23.5 years (range, 4-30). Thirty-eight patients (64%) were male, and 21 (36%) were female. Most tumors were noninvasive, papillary urothelial tumors (49 of 59; 83%), including papillary urothelial neoplasms of low malignant potential (7 of 49; 14%), low-grade papillary urothelial carcinomas (38 of 49; 78%), and high-grade papillary urothelial carcinomas (4 of 49; 8%). Only a few (n=10) of the urothelial tumors were invasive, invading the lamina propria (n=5; 50%), muscularis propria (n=4; 40%), or perivesical soft tissue (n=1; 10%). Clinical follow-up information was available for 41 patients (69%), with a mean follow-up time of 77 months. Of 31 patients with noninvasive papillary urothelial tumors, only 1 patient (3%) later developed an invasive urothelial carcinoma and died of the disease, and 30 of these patients (97%) were alive at the end of follow-up, although 10 (32%) had local tumor recurrences. In the 10 patients with invasive urothelial carcinomas, 3 patients (30%) died of the disease and 5 others (50%) were alive with metastases (the other 2 [20%] were alive with no recurrence). CONCLUSION: Urothelial tumors in young patients are mostly noninvasive, papillary carcinomas and have an excellent prognosis; however, a small subset of patients may present with high-grade invasive urothelial carcinomas that result in poor clinical outcomes.