Co‑occurrence of clear cell renal cell carcinoma and bladder urothelial carcinoma: A case report and literature review.

The co-occurrence of clear cell renal cell carcinoma (ccRCC) and bladder urothelial carcinoma (bUC) is rare, and owing to the lack of a unified treatment plan, the prognosis is poor. The present report describes the case of a 65-year-old male patient with a history of smoking and no history of malignant tumors who presented with hematuria at the Huanghe Sanmenxia Hospital Affiliated to Henan University of Science and Technology (Sanmenxia, China) in July 2021. Urinary system computed tomography urography revealed a right renal tumor, and cystoscopy revealed intravesical lesions. The patient underwent transurethral resection of a bladder tumor + laparoscopic partial nephrectomy + laparoscopic radical cystectomy and bilateral ureterostomy. Pathological examination revealed right-sided ccRCC (pT1aN0M0) and high-grade invasive bUC (pT2N0M0). After surgery, the patient underwent bilateral ureteral single J tube replacement in the outpatient clinic every 3 months. In September 2022, the patient presented with a mass on the right side of the neck. Further examination revealed a space-occupying lesion in the lower part of the left kidney and space-occupying lesions in the neck, axilla, mediastinal lymph nodes and liver. A neck lymph node puncture biopsy suggested UC, and the patient was diagnosed with metastatic UC (T4N0M1). The patient received tislelizumab (200 mg once every 3 weeks) + sunitinib (50 mg/day, administered for 4 weeks with a 2-week interval) for a total of 2 months and died of an advanced tumor in January 2023. In addition, the data of 36 patients with ccRCC and bUC from the literature were analyzed for the present report. The results showed that the median age at first onset was 56.5 years (range, 31-82 years) and the male-to-female ratio was 6:1. Smoking and male sex may be risk factors for this disease, which has a median survival time of 47.5 months. The survival analysis results showed that the pathological stage of bladder cancer may be associated with its prognosis. The present study reviews the potential risks, clinicopathological characteristics and treatment methods of co-occurrence of clear ccRCC and bUC. In conclusion, the high-risk factors for the co-occurrence of ccRCC and bUC were smoking and male sex, and the median survival time was 47.5 months. The pathological stage of bladder cancer may be related to the prognosis.