The Relationship between B7-H4 Expression and Clinicopathological Characteristics in Clinical Stage T1 Conventional Renal Cell Carcinoma

PURPOSE: The diagnosis of clinically early-stage (T1) renal cell carcinoma (RCC) has increased. The present study evaluated the association of B7-H4 expression on the pathological outcome and recurrence of carcinoma in the T1 stage of RCC. MATERIALS AND METHODS: Among patients who underwent partial or radical nephrectomy after diagnosis of T1 stage RCC during the period of January 2000 to March 2007, 102 pathologically confirmed cases of clear cell carcinoma were included in this study. The patients' medical records were reviewed retrospectively. For the immunohistochemical staining tests, the B7-H4 antibody (Abbiotec 1:500) was used, and clinicopathological characteristics were analyzed. RESULTS: The mean age of the patients (39 males: 38.2%, 63 females: 61.8%) was 53.0±12.0 years (range, 31-74 years), and the mean follow-up time was 33.4±21.0 months (range, 6-84 months). B7-H4 expression was positive in 18 cases and negative in 84 cases. Recurrence during the follow-up period occurred in 5 cases in the group with positive B7-H4 expression and in 7 cases in the group with negative B7-H4 expression, respectively (p=0.035). In the univariate analysis, a statistically significant relationship was observed only for the presence of B7-H4 expression (p=0.0019). In the multivariate analysis, other than the expression of B7-H4, cancer size and TNM stage had effects on the recurrence of cancer. CONCLUSIONS: For clear cell RCC, B7-H4 expression had a critical impact on the prognosis of the patients, particularly on the recurrence of the carcinoma in patients with clinical stage T1 RCC.