The location of lymphangiogenesis is an independent prognostic factor in rectal cancers with or without preoperative radiotherapy.

BACKGROUND Lymphangiogenesis and angiogenesis are essential for tumour development and progression. The lymphatic vessel density (LVD) and blood vessel density (BVD) and their relationship to outcome have been studied extensively, however the clinical significance of the location of LVD/BVD in tumour is not known. In the present study, the location and degree of LVD/BVD and their relationship to preoperative radiotherapy (RT), clinicopathological, histopathological and biological factors were studied in rectal cancer patients participating in a Swedish clinical trial of preoperative RT. PATIENTS AND METHODS The location and degree of LVD/BVD were analysed in primary tumours (n = 138/140) and in their subgroups of non-RT (n = 74) and RT (n = 64/66). Further, the degree of LVD/BVD was examined in the corresponding distant normal mucosa (n = 35/31) and adjacent normal mucosa (n = 72/91). All sections were immunohistochemically examined by using D2-40 and CD34 antibodies. RESULTS In the whole series of the patients, a higher LVD at the periphery was related to negative p53 expression (P = 0.03) and favourable survival independent of tumour-node-metastasis stage, differentiation and p53 expression (P = 0.03). LVD was increased in p53-negative tumours after RT (P = 0.01). CONCLUSION LVD at the periphery of the tumour was an independent prognostic factor in rectal cancer patients.