VEGFR3 and CD31 as prognostic factors in renal cell cancer

Aim: To evaluate the expression levels of vascular endothelial growth factor receptor-3 (VEGFR3) and CD31 and assess their associations with grade, stage and survival in patients with renal cell cancer (RCC).

Patients and methods: Our study included 224 consecutive patients who received treatment during the years 1985-1995 in Tampere Finland but had not been treated with modern anti-angiogenesis drugs. All tumor samples were re-classified and investigated using immunohistological techniques. Data were collected from patient records and the Finnish Cancer Registry.

Results: In total, 54.2% and 98.2% of the tumor samples tested positive for VEGFR3 and CD31 expression, respectively. CD31 expression levels were classified into two groups according to the median level revealing that its high expression was nearly significantly associated with low tumor stage (p=0.069). In an age- and gender-adjusted analysis, low expression of CD31 associated with poorer survival. Grade 3 and grade 4 tumors had significantly higher mortality rates compared to those of grades 1-2 (hazard ratio (HR)=4.91; 95% confidence interval (CI)=1.12-20.4; p=0.029 for grade 3 and HR=9.31; 95% CI=2.23-38.8; p=0.002 for grade 4). In addition, stage 2, 3 and 4 tumors revealed that they possessed significantly higher mortality hazard ratios compared to those of stage 1 tumors (HR=2.62; 95% CI=1.27-5.41; p=0.009 for stage 2, HR=4.37;95% CI=2.29-8.3; p<0.001 for stage 3 and HR 13.8; 95% CI=7.18-26.7; p<0.001 for stage 4).

Conclusion: High CD31 expression associated significantly with better survival and VEGFR3 had no association with survival. Both higher tumor grade and stage were associated with a decreased survival time.