Background: Plasmacytoid urothelial carcinoma (PUC) is a rare but aggressive variant of transitional cell carcinoma. In patients with unresectable disease, the most commonly used treatment is combination chemotherapy with methotrexate, vinblastine, doxorubicin and cisplatin (MVAC) or gemcitabine and cisplatin (GC). However, many patients with urothelial carcinoma are cisplatin-ineligible due to renal dysfunction, poor performance status or other comorbidities. We report a case of a cisplatin-ineligible veteran with metastatic PUC who was treated with pembrolizumab.
Case Report: A 71-year-old male veteran with 30 packyear smoking history, schizoaffective disorder and type 2 diabetes found to have multiple right-sided lung nodules and perihilar lymphadenopathy after presenting with atypical chest pain. Staging CT abdomen and pelvis showed bilateral adrenal masses and a large soft tissue mass in the right iliac fossa. Subsequent biopsy of the soft tissue mass had pathology consistent with PUC. As the patient was cisplatin-ineligible due to poor performance status and multiple medical comorbidities, the decision was made to treat with pembrolizumab 2 mg per kg IV every 3 weeks. Repeat CT chest, abdomen and pelvis showed partial response at 3 months and stable disease at 6 months.
Discussion: The KEYNOTE-052 study found that firstline pembrolizumab in cisplatin-ineligible patients with urothelial cancer resulted in complete or partial response in 24% of patients with few adverse effects. However, it is unclear if patients with plasmacytoid variant were included. To our knowledge, this is the first case report of a patient with metastatic PUC not only treated with pembrolizumab but shown to have clinical response.
Conclusions: Given our patient’s clinical response, pembrolizumab is a promising first-line agent for treating cisplatin-ineligible patients with metastatic PUC. Further evaluation is warranted to confirm the benefit of treatment with pembrolizumab in this patient population.
