[Clinical analysis of non-clear cell renal cell carcinoma]

Clinicopathological features and prognosis of metastatic renal cell carcinoma (mRCC) vary by histopathological type. In this study, we analyzed these relationships with regard to non-clear cell RCC (nccRCC). We also analyzed the therapeutic trends for patients with mRCC. We initially identified 367 patients who were diagnosed with RCC and treated in our hospital between 2001 and 2013 ; 55 patients of whom were diagnosed with nccRCC. We reviewed their backgrounds, histopathological types and outcomes. Median age at diagnosis for patients with nccRCC was significantly younger (58.5 years) than for those with clear-cell RCC (66.3 years ; P=0.008) ; however, these histological types did not significantly differ by sex, affected side or rate of mRCC. Of the 55 nccRCC cases, 19 were mRCC, including 5 of the 8 cases of papillary type-2 RCC, and all patients who had either collecting duct carcinoma, sarcomatoid RCC or Xp11 translocation RCC. The most common metastatic site was lymph nodes. Although patients with papillary type-1 and Xp11 translocation RCC had relatively good prognoses, those with papillary type-2, collecting duct carcinoma and sarcomatoid RCC had poor prognoses. Among the 9 patients with nccRCC who received molecular targeted therapy, median survival was 13.3 months. Although existing therapeutic agents may be effective for some patients with nccRCC, identification of new target molecules and innovative drug development are needed in the future.