Collecting Duct Carcinoma of the Kidney: Analysis of 74 Cases From Multiple Centers

Objective: To comprehensively describe the manifestations, diagnosis, treatment and prognosis of the collecting duct carcinoma (CDC) of the kidney.

Materials and methods: We retrospectively collected data from 74 patients with CDC from two centers between January 2001 and December 2020. The clinical characteristics, imaging and pathological features, and diagnostic and treatment methods were analyzed.

Results: The mean age of the patients was 61.5 years, and 54.1% were males. The most common symptoms were low back pain, hematuria, and fatigue. Computed tomography was not specific, with 10.8% of the patients diagnosed with urothelial carcinoma and 4.1% with infectious disease. Thirty-two patients had metastasis at presentation, while 17.6% had tumor thrombus in the venous system. Twenty-two patients underwent renal biopsy, and 50% of the patients were diagnosed with CDC. Sixty-one renal surgeries were performed, and the pathological median diameter was 6.5 cm. Eight patients received immune checkpoint inhibitors, and the objective remission rate was 50%. The median follow-up time was 16 months, while the median overall survival was 24.0 months. The univariate and multivariable analysis showed that sarcomatoid differentiation and absence of renal surgery were predictors of mortality.

Conclusion: CDC is highly aggressive. Patients are commonly diagnosed at an advanced stage. Early surgical treatment can improve prognosis. Though there is still a lack of standard treatment, immune checkpoint inhibitors bring new hope for the treatment of CDC.