Serum gamma-enolase and prognosis of patients with renal cell carcinoma.

Abstract

Increased levels of gamma-enolase (gamma-enolase) have been observed in the sera of patients with renal cell carcinoma. To evaluate the prognostic information of gamma-enolase in this disease, 161 consecutive patients were assessed before initiation of therapy. gamma-Enolase was analyzed in serum using an immunoradiometric assay. The patients were clinically staged and followed up for a median time of 36 months (range, 5-104 months). Actuarial survival was calculated using the Kaplan-Meier method. Elevated levels of gamma-enolase was found in 28 of 61 (46%) patients with distant metastases, compared with 8 of 56 (14%) when the tumor was confined to the kidney. A correlation also was observed between gamma-enolase and tumor grade, with poorly differentiated tumors having the highest levels. In 28 patients with distant metastases and elevated gamma-enolase, the survival time was significantly shorter than that of 31 patients with normal gamma-enolase levels (P < 0.001). The median survival time was 5 and 11 months, respectively. Using Cox proportional hazard model, clinical stage, serum gamma-enolase, and tumor grade were identified as independent prognostic factors. Serum gamma-enolase can be useful as an adjunct in the staging of renal cell carcinoma. It also gives predictive information and might be of value as a marker in adjuvant therapy.