Serum immunosuppressive acidic protein in renal cell carcinoma

Abstract

No useful tumor makers for renal cell carcinoma (RCC) have yet been established. In the present study, the serum IAP level was assessed sa a diagnostic and follow-up marker for RCC. The subject were 16 women and 52 men with RCC (28-87 years old) and 30 healthy adult controls (20-68 years old).
Serum IAP levels were assayed by the single radial immunodiffusion method and the cut-off level was set at 500μg/ml. The IAP level was significantly higher in the RCC than in the controls. The IAP positivity rate was 63.2% in the RCC patients Patients and 16.7% in the controls. Elevation of IAP was related to clinical stage. The IAP Positivity rate was 83.9% in patients with high stage RCC and 35.1% in those with low stage RCC. The prognosis of low stage RCC with IAP level over 1, 000μg/ml was quite poor. In contrast, even high stage patients with IAP levels of 500μg/ml or less had a longer survival compared with those having elevated IAP levels. Additionally, in the low stage patients, the IAP level decreased significantly after radical nephrectomy compared with that at diagnosis. Patients with the IAP levels of 500μg/ml or less after nephrectomy also had a longer survival than those with the levels over 500μg/ml.
Based on these results, it was concluded that IAP may be auseful marker for RCC, although it appears valuable for assessing the prognosis than for diagnosis. A more accurate assessment of the prognosis of RCC was possible using a combination of the IAP value and clinical stage.