Patient selection: renal cell carcinoma
A paraneoplastic elevation os serum alkaline phosphatase was defined as an elevated serum alkaline phosphatase with exclusion of other explanations for the increase.
The presence of a paraneoplastic elevation of serum alkaline phosphatase was associated with a worse prognosis.
Additional prognostic factors:
(1) higher tumor stage
(2) additional paraneoplastic findings (hypercalcemia, thrombocytosis, fever, anemia, transaminase elevation, coagulopathy, erythrocytosis)
(3) failure of the serum alkaline phosphatase to normalize after tumor resection (implies residual tumor and/or metastases) or its reappearance after an initial drop
where:
• The definition of paraneoplastic elevation of the serum alkaline phosphatase was an elevated serum alkaline phosphatase with no other explanation. A patient with elevated serum alkaline phosphatase and elevated transaminases might have occult liver disease.
• The impact of the paraneoplastic elevation of the serum alkaline phosphatase level was greater for Stage I tumors. The 10 year survival for a Stage I tumor and normal serum alkaline phosphatase was 85% vs 20% if the serum alkaline phosphatase was elevated.
The presence of a normal serum alkaline phosphatase after surgery does not guarantee that there is no residual tumor.
