Increased tumour angiogenesis in SOX11‐positive mantle cell lymphoma.

Aims: Mantle cell lymphoma (MCL) is a heterogeneous disease with an aggressive behaviour in most cases, which is associated with expression of sex determining region‐Y‐box11 (SOX11). Experimental studies have shown that SOX11 expression is associated with an angiogenic switch characterised by increased expression of angiogenic‐related signatures and vascularisation of murine tumours. However, the relationship between angiogenesis and SOX11 expression in primary tumours is not well understood. Therefore, the aim of this study was to evaluate the development of microvascular angiogenesis in primary MCL in relation to SOX11 expression and its potential prognostic value. Methods and results: Fifty‐six patients diagnosed with MCL, 38 SOX11‐positive and 18 SOX11‐negative, were studied. The relative intratumoral microvascular area (MVA) and microvessel density (MVD) (number of intratumoral microvessels/μm2) were measured on CD34‐stained slides using a computerised image analysis system. SOX11‐positive MCL showed a significant higher microvascular development than negative tumours (median MVA = 14.5 × 10−3 versus 5.0 × 10−3P < 0.001; median MVD = 18.6/μm2 versus 14.2/μm2, P = 0.021). Analysing the MVA and MVD as continuous variables, a high MVD was associated with shorter overall survival (P = 0.004), and a similar tendency was observed for high MVA (P = 0.064). The microvascular development was not related to the Ki‐67 proliferative index or 17p/TP53, 9p or 11q alterations. Conclusions: These findings suggest that SOX11 promotes an angiogenic phenotype in primary MCL, which may contribute to the more aggressive behaviour of these tumours. [ABSTRACT FROM AUTHOR]