Prognostic value of histopathological response to radiotherapy and microvessel density in oral squamous cell carcinomas

The prognostic value of histopathological response to preoperative radiothe rapy (50 Gy) in radically resected oral Carcinomas was studied in 39 consec utive patients. Microvessel density (MVD) was evaluated for relation to rad ioresponse and outcome. Resected tumour tissue was examined histopathologic ally and response to radiotherapy was scored according to induced morpholog ical changes. Pretreatment biopsies were stained with antibodies to von Wil lebrand factor to evaluate MVD in hot-spot regions, in stromal tissue and i n tumour epithelial tissue. Histopathological response to radiotherapy was highly prognostic of local failures and survival (p = 0.002), though micros copic surgical radicality was obtained, In good responders to preoperative radiotherapy, the 5-year survival rate was 68% compared with 24% in poor re sponders. In 12 patients with local recurrence after radical surgery, 11 ha d poor histopathological radiotherapy responses. In univariate analysis, a high MVD score in tumour epithelium was associated with poor clinical outco me but MVD did not correlate with histopathological radiotherapy response.