Clinical utility of the Glasgow Prognostic Score in patients undergoing curative nephrectomy for renal clear cell cancer: basis of new prognostic scoring systems

Abstract

Background: Measurement of the systemic inflammatory response in malignancy has been recently refined using a selective combination of C-reactive protein and albumin (modified Glasgow Prognostic Score, mGPS). This has prognostic value in patients with metastatic kidney cancer. This study examines the prognostic value of the mGPS in patients undergoing curative nephrectomy for clear cell cancer.

Methods: Patients with localised renal cell carcinoma undergoing potentially curative resection between March 1997 and July 2007 in a single institution were prospectively studied. The mGPS, University of California Los Angeles Integrated Staging System (UISS), 'Stage Size Grade Necrosis' (SSIGN), Kattan and Leibovich scores were constructed.

Results: A total of 169 patients were studied. The minimum follow-up was 49 months; the median follow-up of the survivors was 98 months. During this period, 35 patients died of their cancer; a further 24 patients died of intercurrent disease. On univariate survival analysis of the scoring systems, Kattan (P<0.05), UISS (P<0.001), SSIGN (P<0.001) and Leibovich (P<0.001) were significantly associated with cancer-specific survival. Using cancer-specific mortality at 4 years as an endpoint, the area under the receiver operator curve was 0.726 (95% CI 0.629-0.822; P=0.001) for Kattan, 0.776 (95% CI 0.671-0.880; P<0.001) for UISS, 0.812 (95% CI 0.733-0.892; P<0.001) for SSIGN, 0.778 (95% CI 0.666-0.889; P<0.001) for Leibovich and 0.800 (95% CI 0.687-0.912; P<0.001) for the mGPS scoring system. On multivariate analysis of significant independent scoring systems and mGPS, UISS (HR 3.08, 95% CI 1.54-6.19, P=0.002) and mGPS (HR 5.13, 95% CI 2.89-9.11, P<0.001) were significant independent predictors of cancer-specific survival.

Conclusions: The present prospective study shows that the mGPS, an inflammation-based prognostic score, is at least equivalent to and independent of other current validated prognostic scoring systems for patients undergoing curative nephrectomy for renal clear cell cancer. The mGPS is simple, measured preoperatively, based on well-standardised, widely available protein assays, and therefore provides an objective and rational basis before treatment for future staging systems in patients with operable renal cancer.

Figure 1

The relationship between the mGPS (0, 1 and 2 from top to bottom) and cancer-specific survival in patients undergoing curative nephrectomy for renal clear cell cancer.