[Occurrence of Distant Metastasis During Bladder Presevation in T1 high-grade Bladder Cancer: Report of Three Cases].

We report three patients with T1 high-grade (HG) bladder cancer who suffered from distant metastasis during bladder preservation. The patients were a 48-year-old female (Case 1), a 75-year-old female (Case 2) and an 82-year-old male (Case 3) with the chief complaint of asymptomatic gross hematuria. The histopathological diagnoses of the initial transurethral resection of the bladder tumor (TURBT) and second TURBT were urothelial carcinoma, pT1, HG and no malignancy in all three patients. Bladder tumors of all patients revealed sessile growth pattern and no presence of carcinoma in situ. Case 2 and 3 did not receive BCG vesical instillation after the second TURBT. Lymph node metastases appeared in Case 1 and Case 2 and lung metastasis appeared in Case 3. Tumor budding (TB) was positive in Case 1 and Case 2. Variant histology (VH) of nested morphology was detected in Case 1 and VH of inverted morphology in Case 2 and Case 3. Twenty-four months after the initial TURBT, Case 1 died due to cancer progression after cisplatin-based chemotherapy and pembrolizumab therapy. Thirty-three and 11 months after the initial TURBT, Case 2 and Case 3 were alive without cancer progression after cisplatin-based chemotherapy and/or pembrolizumab therapy, respectively. The two patients with T1 HG bladder cancer with TB had lymphatic metastasis and the patient without TB had hematogenous metastasis. Nested morphology is reportedly categorized as high-risk disease and inverted morphology as low-risk disease. TB might be correlated with lymphatic metastasis in T1 HG bladder cancer, and TB should be considered in the management of T1 HG bladder cancer. In the case of VH, the guidelines should be followed during the treatment decision of T1 HG bladder cancer.