Impact of macroscopic tumour necrosis to predict survival of patients with surgically resected renal cell carcinoma.

OBJECTIVE: The determination of further prognostic factors is essential for the establishment of risk groups for patients with surgically treated renal cell carcinoma (RCC). The objective of this study was to validate the prognostic value of macroscopic tumour necrosis, concerning postoperative survival.

MATERIAL AND METHODS: A total of 607 patients (387 men, 220 women), who had undergone surgical treatment for RCC, was retrospectively reviewed. Necrotic areas in the tumour were identified macroscopically followed by microscopic confirmation. Cancer-specific survival (CSS) and overall survival (OS) were estimated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression models were fitted to determine associations between tumour necrosis, clinical and pathological features, and survival. In 447 patients who were still alive at the end of the study, median follow-up was 66 months (mean 71.2 months).

RESULTS: Tumour necrosis was identified in 25.5% of patients (n=155). After 5 years, CSS and OS in the group of patients with tumour necrosis amounted to 77.0% and 64.4%, respectively, compared with 89.8%and 81.9% in the group of patients without tumour necrosis (in each case p<0.001). Patients with tumour necrosis significantly more often showed a metastatic stage, lymph-node involvement, a higher pathological tumour stage, a higher grading and a larger tumour size. In addition, a more frequent appearance of microvascular invasion and thrombocytosis could be proven in patients with tumour necrosis in comparison to patients without these histopathological findings. On multivariate regression analysis, only metastatic stage, lymph-node involvement, platelet count >400/nl and tumour necrosis remained significant for survival (CSS, OS).

CONCLUSIONS: According to the results, tumour necrosis may be a useful factor in the prognostic assessment of patients with RCC. The integration of this parameter in prognostic models for postoperative survival is recommended.