PD-L1 expression as predictor of immunotherapy eligibility in penile squamous cell carcinoma patients

Abstract

Background: Penile cancer is a rare malignancy and potentially lethal disease with an incidence of 0,6-2,1 per 100.000. Squamous cell carcinoma (SqCC) is the most commonly found penile malignancy. PD-L1 is a tumor marker that co-stimulates the receptor PD-1 to suppress T-cell-mediated antitumor immunity. Methods: This study is a retrospective cohort study with a total sampling method. The slides taken from the biopsies of seventy-six male patients from Haji Adam Malik Hospital diagnosed with penile squamous cell carcinoma who have already undergone penile biopsy were re-examined for this study, and PD-L1 levels were measured accordingly. Statistical methods were used to assess the association between PD-L1 levels and with SqCC stage. Results: A total of 76 male patients are the subjects of this study. PD-L1 positivity is identified in 25 patients with +1 intensity in 10 patients (13,2%), +2 in 7 patients (9,2) and +3 intensity in 8 patients (10,5%). There are 36 patients (47,4%) diagnosed with stage T3 SqCC, 35 patients (46,1%) with stage N2 SqCC, and 10 patients (13,2%) with stage M1 SqCC. There is significant correlation between PD-L1 expression and metastasis (p=0,022). However, there is no significant correlation between PD-L1 expression and stage N tumor (p=0,167). Conclusions: PD-L1 highly expressed in advanced stage penile SqCC (32.9%), which is associated with the high-risk clinicopathologic features and poor clinical outcomes. These findings showed a potential usage of immunotherapy in advanced penile SqCC treatment.