The role of gamma-glutamyl transpeptidase in the preoperative metastatic evaluation of renal cell carcinoma.

PURPOSE

We evaluated gamma-glutamyl transpeptidase as an indicator of metastatic disease in patients with renal cell carcinoma.

MATERIALS AND METHODS

We reviewed the records of 53 patients with metastatic renal cell carcinoma, and compared serum alkaline phosphatase and gamma-glutamyl transpeptidase with the site of metastases. These results were then compared to those in 29 patients with clinically localized renal cell carcinoma.

RESULTS

Overall gamma-glutamyl transpeptidase was elevated in 37 patients (69.8%) with metastatic disease, while alkaline phosphatase was elevated in 16 (30.2%, p < 0.025). Gamma-glutamyl transpeptidase was increased in more patients with hepatic metastases only than alkaline phosphatase (p < 0.025) and in all groups it was a better predictor of metastases than alkaline phosphatase. Gamma-glutamyl transpeptidase was also increased in significantly more patients with metastatic renal cell carcinoma (37 of 53) compared to 1 of the 27 with localized renal cell carcinoma (p < 0.001).

CONCLUSIONS

Gamma-glutamyl transpeptidase was increased in a large percent of patients with metastatic renal cell carcinoma, and it was normal in the majority with localized renal cell carcinoma. We conclude that gamma-glutamyl transpeptidase should be included as well as alkaline phosphatase in the preoperative metastatic evaluation of patients with renal cell carcinoma. Elevated gamma-glutamyl transpeptidase should prompt a search for bone as well as liver metastases.