Complete remission following pembrolizumab therapy for a patient with nephroureterectomy positive-margin carcinoma in situ and bladder cancer unresponsive to Bacille Calmette-Guérin therapy.

An 82-year-old man was diagnosed with synchronous non-muscle-invasive bladder cancer and left lower ureteral carcinoma. He underwent transurethral resection of the bladder tumor, followed by total left nephroureterectomy after preoperative chemotherapy with four courses of gemcitabine and carboplatin. Histopathological findings showed positive-margin carcinoma in situ. In addition, since recurrence of non-muscle-invasive bladder cancer was observed in the bladder, Bacille Calmette-Guérin intravesical infusion therapy was performed, but the cancer persisted due to treatment resistance. After that, pembrolizumab therapy was performed, and complete remission was achieved.

Primary lung cancer treatable with radical resection after complete remission with pembrolizumab therapy following gemcitabine and carboplatin chemotherapy for multiple metastases of bladder cancer.

Introduction: We report a patient with the complete remission of multiple metastases and primary bladder lesions of bladder cancer who developed primary lung cancer requiring radical resection. Case presentation: A 68-year-old man diagnosed with invasive bladder cancer, right hydroureteronephrosis, and multiple metastases were administered six courses of gemcitabine and carboplatin chemotherapy and thereafter has been receiving pembrolizumab therapy. Bladder cancer and multiple metastases decreased in size, whereas a ground-glass opacity lesion in the lung gradually increased in size. Fluorodeoxyglucose-positron emission tomography revealed the accumulation of fluorodeoxyglucose in the ground-glass opacity lesion only. The patient was diagnosed with primary lung cancer and underwent a thoracoscopic lobectomy. Histopathological findings showed ALK-negative, EGFR L858R mutation-positive invasive adenocarcinoma with a programmed death-ligand 1 tumor proportion score of less than 1%. Conclusion: This is the first case report of patients with the complete remission of multiple metastases of bladder cancer who developed primary lung cancer requiring radical resection.