Lymphangiogenic VEGF-C and VEGFR-3 expression in genetically characterised gastrointestinal stromal tumours

This study aimed to assess the distribution of VEGF-C and VEGFR-3 expression in gastrointestinal stromal tumours (GISTs), and to analyse the value of lymphatic vessel density (LVD) in a tumour that is believed to preferentially metastasize through blood vessel conduits. A panel of immunohistochemical antibodies was used to evaluate 51 cases of genetically characterised GISTs: VEGF-C, VEGFR-3, D2-40 (for LVD assessment) and CD31 (for blood vessel density--BDV--assessment). The results were correlated with the clinical-pathological data. The large majority of cases (86.2%; 44/51) showed a mutation of the KIT gene, most of them (72.5%; 37/51) revealing mutations in exon 11. VEGFR-3 was predominantly expressed in KIT mutated GISTs (p=0.019). High LVD was correlated with the absence of metastasis (p=0.010) and high BVD showed a positive correlation with the occurrence of metastasis (p=0.049). The strong expression of VEGF-C and VEGFR-3 in GIST's cells was not correlated with the clinical parameters of aggressiveness, nor with high LVD.