Prognostic significance of preoperative molecular serum analysis in renal cancer

Purpose: We evaluated the postoperative clinical course of patients with renal cancer identified preoperatively by microsatellite analysis to examine the correlation between microsatellite alterations and risk of disease recurrence and patient mortality 2 years after nephrectomy. Experimental Design: A panel of 28 microsatellite markers was used previously to assess loss of heterozygosity and microsatellite instability in urine, serum, and tumor DNA of 30 patients with clinically organ-confined renal masses who underwent partial or radical nephrectomy. The clinical reports and imaging data in the medical records of patients with a minimum follow-up of 2 years were retrospectively reviewed to determine their postoperative course. Results: Two-year follow-up was available for the 30 patients (100%) who entered the study. Mean age was 61.6 ± 12.9 years (range, 21-77 years). Tumor stage was associated with patient mortality (P = 0.03). Tumor grade was associated with mortality (P = 0.03) and disease recurrence (P < 0.01). The frequency of microsatellite alterations (loss of heterozygosity) found in the preoperative serum of patients with renal masses served as a prognostic indicator for disease recurrence (P < 0.01). Conclusions: Analysis of microsatellite alterations found in preoperative blood samples is a promising method for the detection of renal cancer. The presence of frequent molecular changes in preoperative serum was associated with disease recurrence. These findings suggest a role for microsatellite analysis in future studies attempting to stratify patients with clinically organ-confined renal cancer into low- and high-risk prognostic groups. Larger prospective randomized trials are needed to validate the clinical utility of this observation.