Histopathological Subtypes and PD-L1 Expression in Primary Urethral Adenocarcinoma: A Series of 5 Cases

Abstract

Background and Objectives Urethral adenocarcinoma is a rare disease with poor prognosis that can display multiple histologic patterns and has an unclear histogenesis. Radical surgery with extensive periurethral resection is the preferred therapeutic approach. Both chemotherapy and radiotherapy have been used as complementary treatment options. Due to the tendency of these tumors to recur, treatment-associated complications, and the limited choice of therapeutic options, patient management can be difficult. Given the lack of literature regarding immunotherapy in urethral adenocarcinoma, our objective was to explore the expression of programmed death receptor-ligand 1 (PD-L1) throughout the different histological subtypes of primary urethral adenocarcinoma. Methods We reviewed all primary urethral adenocarcinomas diagnosed at our hospital between 1965 and 2019, performed immunohistochemical assays on the tissue blocks, classified them according to their histology and origin, and performed PD-L1 (22C3) immunohistochemistry assays in all cases. Results We found a total of 5 cases of primary urethral adenocarcinoma. All of the patients were women. One of the cases was a cribriform adenocarcinoma, 2 were columnar-mucinous adenocarcinomas, and 2 were clear cell adenocarcinomas. One of the clear cell adenocarcinomas strongly expressed PD-L1. In addition, a profuse inflammatory infiltration constituted by CD3-positive and CD8-positive T lymphocytes within tumor cells was observed in this case. None of the other cases showed PD-L1 expression. Conclusions In conclusion, some urethral adenocarcinomas may strongly express PD-L1 and thus could potentially allow the use of immunotherapy in selected cases of advanced or recurrent adenocarcinoma.

Chemotherapy combined with immunotherapy in primary female urethral squamous cell carcinoma: a case report

“…A search of the literature showed that there are few data on the detection of PD-L1 or the use of PD-L1 inhibitors in primary urethral cancer. 21,22 Antigen-presenting cells, such as human monocytes, as well as activated human and murine dendritic cells, express PD-L1. 23 PD-1 inhibitors mainly act on PD-1 inhibitor molecules on the T cell membrane.…”

“…A search of the literature showed that there are few data on the detection of PD-L1 or the use of PD-L1 inhibitors in primary urethral cancer. 21 , 22 …”

Immune checkpoint inhibitor in a case with primary urethral adenocarcinoma with lung metastasis

“…Additionally, the patient refused the chemotherapy because of adverse reactions including severe systemic edema, hand and foot skin peeling, and lower extremity venous thrombosis. Recent study found that some urethral adenocarcinomas may strongly express PD-L1 and thus could potentially allow the use of immunotherapy in selected cases of advanced or recurrent adenocarcinoma [13]. We wonder if the immune checkpoint inhibitor is working for this patient.…”