Intensity of vascular endothelial growth factor expression is associated with increased risk of recurrence and decreased disease-free survival in papillary thyroid cancer

Background, Vascular endothelial growth factor (VEGF) induces proliferation of endothelial cells, stimulates angiogenesis, and increases vascular perm eability. Increased VEGF expression has been associated with poor clinical outcomes in many malignancies. Several recent reports have documented over expression of VEGF in papillary thyroid cancer. We hypothesized that increa sed expression of I VEGF would be associated with either an increased risk of recurrence or a decreased recurrence-free survival in papillary thyroid cancer. Methods, Immunohistochemistry was used to detect VEGF expression in archiva l paraffin-embedded surgical thyroid specimens from 96 subjects with papill ary thyroid cancer Results, VEGF expression was detected in 98% (94/96) of the samples, predom inantly of slight-to-moderate intensity in the majority of malignant cells. However, the specific finding of a diffuse pattern of intense immunostaini ng for VEGF was detected significantly more often than less intense, patchy immunostaining patterns in subjects with distant metastasis at diagnosis ( 63% versus 15%, P =.005), local recurrence (58% versus 13%, P =.001), and d istant recurrence (83% versus 14%, P =. 001). Furthermore, this specific pa ttern of diffuse, intense VEGF expression was associated with a significant ly shorter recurrence-free survival than other staining patterns (P =.007). Conclusions:. These data demonstrate that the immunohistochemical pattern o f VEGF staining in the initial surgical specimen is strongly associated wit h the incidence of local and distant metastasis in papillary thyroid cancer .