Histochemical study of angiogenesis in basaloid squamous carcinoma of the esophagus

Angiogenesis of esophageal basaloid squamous carcinoma (BSC) was studied im munohistochemically and compared with that of squamous cell carcinoma (SCC) . In tissues taken from six patients with esophageal BSC and 35 with esopha geal SCC, angiogenesis was evaluated by measuring microvessel density (MVD) , defined as the microvessel count determined using factor VIII-related ant igen immunostaining, and by measuring immunoreactivity of vascular endothel ial growth factor (VEGF) and thymidine phosphorylase (dThdPase). Three of t he six patients with BSC had distant metastases. There was no difference of MVD between BSC and SCC (22.0 +/- 4.6 vs. 27.6 +/- 9.4). VEGF expression t ended to be more frequently observed in BSC than in SCC (100% vs. 60.0%; p= 0.066). Strong expression of VEGF was detected in three BSC with distant me tastases; however, there was no difference in the rate of strong VEGF expre ssion between BSC and SCC. The MVD in the cases of BSC with strong VEGF exp ression, i.e. in the cases with distant metastases, was higher than that in the cases of BSC with weak VEGF expression (p=0.049). There was no differe nce in dThdPase expression of the cancer cells between BSC and SCC (50.0% v s. 54.3%), whereas the infiltrating stromal cells of all the BSC expressed dThdPase. Strong dThdPase expression in the cancer cells or in the infiltra ting stromal cells was observed in two and three BSC, respectively. However , there were no differences in the rate of cancer cells or stromal cells wi th strong dThdPase expression between BSC and SCC. In one BSC with high MVD and distant metastases, VEGF and dThdPase were both strongly expressed. Th e vascularity of esophageal BSC was not different from that of SCC. VEGF ma y participate in angiogenesis of esophageal BSC and may influence the rate of metastasis in esophageal BSC patients. dThdPase may play a partial rule in angiogenesis and metastasis in some cases of BSC.