Analysis of CD44 isoform v10 expression and its prognostic value in renal cell carcinoma

Objective To examine the expression of CD44 isoform v10 (CD44v10) in patien ts with renal cell carcinoma (RCC), analyse its role in RCC and its relatio nship with conventional clinical-histopathological experience. Materials and methods Sixty-four RCC specimens and five metastatic specimen s were analysed immunohistochemically using a CD44v10 specific antibody. Th e expression of CD44v10 was compared with the histological grade and clinic al or pathological stage of the tumours. Results Of the 64 primary tumour specimens, 22 (34%) expressed CD44v10 prot ein; all of these positive specimens were clear-cell and mixed-cell RCC. St aining was also positive in four of five metastatic specimens and negative in all four cases of granular cell carcinoma. CD44v10 expression was signif icantly correlated with the histological grade (P<0.0001), clinical stage ( P=0.0050) and pathological stage (P=0.0143) of the rumours, The prognosis f or patients with clear-cell RCC who were CD44v10-positive was worse than fo r patients who were CD44v10-negative (P<0.0001). In subgroups with differen t tumour stage (less than or equal to pT2 or greater than or equal to pT3), the prognosis for patients with positive CD44v10 expression was also worse than for those with no expression (P<0.05). Conclusion The expression of CD44v10 correlated significantly with histolog ical grade, clinical and pathological stage, and with survival in patients with clear-cell RCC. CD44v10 protein may play a role in the progression of clear-cell and mixed-cell RCC, and thus the analysis of CD44v10 expression may provide useful prognostic information.