Tumor Budding Is Significantly Associated with Lymph Node Metastasis in Invasive Ductal Breast Cancer
Mafalda Trippel, Katrin Pfaltz, Inti Zlobec, Coya Tapia. University of Bern, Bern, Switzerland
Background: Tumor budding is a phenomenon associated with epithelial mesenchymal transition and correlates with tumor invasiveness and metastasis. Whether tumor budding is a histomorphological feature of invasive breast cancer has not yet been determined. Therefore, we investigated the prognostic value of peritumoral (PTB) and intratumoral (ITB) budding in invasive ductal breast cancer.
Design: Two pathologists counted tumor buds within the tumor (ITB) and at the periphery (PTB) of 68 primary invasive ductal breast cancers as follows: Whole tissue sections were stained for PanCK (AE1/AE3) and hot-spots of tumor buds (i.e., isolated tumor cells or small groups of up to 5 cells) were counted at 400x. A cut-off of 10 buds was established to assign “high-grade” PTB or ITB. PTB and ITB were then correlated with clinico-pathological features.
Results: Fifty-three percent (n=36) and 56% (n=38) were high grade for ITB and PTB, respectively. High grade PTB was significantly (p=0.0262) associated with lymph node metastasis and was more frequent in hormone receptor positive (ER: 62%, PR: 57%), her2 negative (59%) and larger breast cancers (>T3: 61%). ITB was significantly (p<0.008) associated with hormone receptor positive tumors and was more frequent in her2 negative (56%) and larger tumors (>T3: 62%). PTB and ITB didn't show an association with tumor grading. PTB and ITP were significantly correlated (p<0.0001).
Conclusions: For the first time, we could show that PTB is a strong (p=0.0262) predictive tumor feature for lymph node metastasis in invasive ductal breast cancer. Larger tumors have more tumor buds but only PTB seems to play a role in invasiveness. This may be due to the lymph vessels at the tumor periphery being more numerous. Whether tumor budding should be implemented in the diagnostics of breast cancer should be determined by further review in the future.
Tuesday, March 5, 2013 9:30 AM
Poster Session III # 28, Tuesday Morning