Clinicopathological characteristics and oncological outcomes in patients with renal cell carcinoma registered in 2007: The first large-scale multicenter study from the Cancer Registration Committee of the Japanese Urological Association.

Objectives: To describe the clinicopathological features and oncological outcomes of renal cell carcinoma diagnosed in Japan in 2007, the results of the large-scale renal cell carcinoma registration study carried out by the Japanese Urological Association are reported.

Methods: The renal cell carcinoma survey was carried out by the Japanese Urological Association in 2012 to register newly diagnosed renal cell carcinoma cases in 2007 from 340 institutions nationwide. The survey included clinicopathological details, such as sex, age, family history, past history, smoking history, body mass index, reason for diagnosis, TNM classification, stage, histopathology, treatment and clinical outcomes.

Results: A total of 3663 cases diagnosed in 2007 were registered in this renal cell carcinoma registry program from 340 institutions. A total of 15 patients with a final diagnosis of oncocytoma were excluded, and 3648 cases of renal cell carcinoma were analyzed to evaluate oncological outcomes. The patients' median age was 63.9 years (range 5.9-95.1 years). Clear cell renal cell carcinoma was the most common histological subtype (77.2%), followed by papillary (5.0%) and chromophobe (3.2%) renal cell carcinoma. The most common initial treatment was radical nephrectomy (72.6%), and the most common secondary treatment was cytokine therapy (13.1%). Five-year overall survival rates in stages I, II, III, and IV were 94.8%, 90.2%, 78.8% and 39.6%, respectively. The 5-year overall survival rates for clear cell, papillary and chromophobe renal cell carcinomas, and carcinoma of the collecting ducts of Bellini were 88.6%, 79.8%, 93.0% and 40.0%, respectively.

Conclusions: The present report is the first nationwide large-scale study to describe the clinicopathological characteristics and oncological outcomes of patients with renal cell carcinoma in Japan. Oncological outcomes depend on the clinical stage and histological subtype. Further investigations will be required to show improved oncological outcomes in the molecular targeted therapy era using the results of the present study as a baseline.