1988 Volume 79 Issue 2 Pages 220-226
To clarify whether serum γ-enolase is a useful marker for renal cell carcinoma (RCC), serum levels of α- and γ-enolases in RCC patients were determined using a highly sensitive enzyme immunoassay system. Aγ/α+γ value, the proportion of the γ-enolase to total enolases, was calculated for each serum sample.
Serum levels of γ-enolase in healthy subjects (n=100) ranged 1.6-5.8ng/ml (mean±SD: 3.1±0.9ng/ml). The upper limit of normal serum γ-enolase, defined as the mean plus three standard deviations was 6ng/ml, and so all values greater than 6ng/ml were considered to be positive. Of 65 patients with RCC, 40 (63%) had elevated serum levels of γ-enolase. Their mean value of 8.3±4.6ng/ml (n=61) was significantly higher than that of healthy subjects (p<0.001). On the other hand, serum levels of α-enolase were 71±55ng/ml in RCC patients and 67±24ng/ml in healthy subjects. Consequently, the value of γ/α+γ in serum of RCC patients (13.6%) was higher than that of normal subjects (4.7%) (p<0.001). The positive rates of serum γ-enolase for RCC were 52% in stage I, 50% in stage II, 67% in stage III and 68% in stage IV. The mean value of serum γ-enolase in patients with high-stage tumors (III+IV) was significantly higher than that for low-stage tumors (I+II) (p<0.05). In 23 patients treated by complete surgical excision, serum γ-enolase was significantly reduced after the operation (p<0.05). Furthermore, when distant metastasis appeared, serum γ-enolase increased in all the 6 patients for whom serial measurements were performed.
Serum γ-enolase could be a useful marker for staging and monitoring the clinical course of patients with RCC.
