PD-L1 Expression: Predicting Immunotherapy Response in Urothelial Carcinoma

By: Julia Fiederlein Cipriano, MS
Posted: Friday, September 22, 2023

The high incidence of urothelial carcinoma in Lebanon is contrasted by a lack of data regarding PD-L1 expression by Combined Positive Score (CPS) in patients with advanced disease. Thus, Fadi G. Haddad, MD, of Saint Joseph University, Beirut, Lebanon, and colleagues used this system to evaluate the prevalence of PD-L1 positivity in such a population from this Middle Eastern nation. Their findings, which were published in the journal BMC Cancer, revealed comparable patterns to those reported in the occidental literature.

“PD-L1 expression, as a potential predictor of response to immunotherapy, concerns the same percentage of the Lebanese patients with urothelial carcinoma,” the investigators commented. “Thus, our population deserves ‘the luxury’ to access immunotherapy for urothelial tumors and avoid any cancer treatment disparities.”

The analysis focused on 101 patients (median age, 71 years) who received treatment for muscle-invasive or advanced urothelial carcinoma between January 2017 and March 2021. Of this population, 78% were either current or former smokers. Immunohistochemistry was performed using the 22C3 anti–PD-L1 antibody clone; PD-L1 positivity was defined by CPS scores of at least 10.

Pathologic examination identified conventional urothelial carcinoma in 92% of patients. A total of 43% of all tumor specimens were found to be PD-L1–positive. The maximal CPS score of 100 was reported in 12 patients; in this population, the basal molecular subtype seemed to be enriched. However, no significant associations were found between PD-L1 expression (positive vs. negative) and both clinical data (sex, smoking status, stage group, site of metastasis, estimated glomerular filtration rate, and prior therapy) and histopathologic and molecular characteristics (histologic variant, histologic differentiation, and molecular group).

Disclosure: For full disclosures of the study authors, visit bmccancer.biomedcentral.com.

BMC Cancer