Angiogenesis is redundant for tumour growth in lymph node metastases

Aims: Angiogenesis is essential for the growth of solid tumours, As the rol e of angiogenesis is unclear in the pathogenesis of primary lymph node (LN) tumours, we wondered whether neoangiogenesis was important in supporting a nd promoting the growth of tumours in LNs, Methods and results: We investigated 16 cases of squamous carcinoma involvi ng oral cavity (n = 9) and larynx/pyriform fossa (n = 7), all of whom had l ymph node metastases. Sections of the primary tumour, uninvolved mucosa, me tastatic LN and nonmetastatic LN were double-immunostained with factor VIII -related antigen and MIB-1, Proliferating blood vessels, i.e, neoangiogenes is, was identified by coexpression of factor VIII-related antigen-stained b lood vessels and MIB-1 staining of the endothelial cell nuclei. Counts were performed in an area of 4 mm(2) Primary tumours (127-188.7), uninvolved mu cosa (54-84.5) and metastatic LNs (123.5-167) had significantly lower vesse l counts than nonmetastatic LNs (194-253.9) (P = 0.003: P < 0.001: P < 0.00 1, respectively). With regard to neoangiogenesis, primary tumours (1.7-5) h ad significantly higher counts than uninvolved mucosa (0-0.4), nonmetastati c LNs (0-0.4) and metastatic LNs (0.9-2.4) (P < 0.001: P < 0.001: P = 0.047 , respectively). Conclusions: Our data suggest that because of the rich native vascularity o f lymph nodes, neoangiogenesis is redundant for the growth of metastatic tu mour.