Prognostic value of carbonic anhydrase IX and HIF-1α in renal cell carcinoma

Objective: In this study, we evaluated the prognostic value of carbonic anhydrase IX (CA9) and HIF-1α and their relations with anatomic, histopathologic and clinic prognostic factors.Materials and Methods: Immunohistochemical analysis was performed on paraffin-embedded specimens from 39 patients treated with a nephrectomy for renal cell carcinoma. The immunoreactivity levels of CA9 and HIF-1α were classified into four groups: 0%, 1-25%, 26-50%, >50% for CA9; and ≤1-10%, 11-50%, 51-80%, >80% for HIF-1α. The CA9 and HIF-1α stains were compared with the patient’s age, sex, tumor volume, recurrence status, T stage and Fuhrman grade. Results: The age distribution of all patients with clear cell renal cell carcinoma (RCC) was as follows: 23 (59%) were older than 50, and 16 (41%) were younger. Twenty-eight patients (71.8%) were male, and 11 (28.2%) were female. Among these patients, 34 (87.2%) survived, and 5 (12.8%) died because of RCC. Seven (17.9%) patients had a recurrence after undergoing a nephrectomy. Twenty-four (61.5%) patients were classified as stage T1 and 15 (38.2%) as stage T2. Thirty-three (84.6%) patients were classified as Fuhrman grade 2 and six (15.4%) patients as Fuhrman grade 3. Although there were different degrees of staining, immunohistochemical staining was positive in all pathological samples for either CA9 or HIF-1α (7 1-25%, 15 26-50%, 17 >%50 for CA9; 11 <10%, 10 10-50%, 14 50-80%, 4 >80% for HIF-1α). Among the CA9 immunoreactive-positive patients, the number of male patients was statistically higher in the 1-25% group than the 26-50% and >50% groups (p=0.019). Among HIF-1α immunoreactive-positive patients, the ≤%10 group had a statistically lower number of tumors sized >4 cm than the other groups (p=0.01). Conclusions: We noted that there was no relationship between CA9 and HIF-1α expression with other prognostic clinicopathologic features.