Evaluation of EphB4 as Target for Image-Guided Surgery of Breast Cancer.

BACKGROUND: Targeted image-guided surgery is based on the detection of tumor cells after administration of a radio-active or fluorescent tracer. Hence, enhanced binding of a tracer to tumor tissue compared to healthy tissue is crucial. Various tumor antigens have been evaluated as possible targets for image-guided surgery of breast cancer, with mixed results. METHODS: In this study we have evaluated tyrosine kinase receptor EphB4, a member from the Eph tyrosine kinase receptor family, as a possible target for image-guided surgery of breast cancers. Two independent tissue micro arrays, consisting of matched sets of tumor and normal breast tissue, were stained for EphB4 by immunohistochemistry. The intensity of staining and the percentage of stained cells were scored by two independent investigators. RESULTS: Immunohistochemical staining for EphB4 shows that breast cancer cells display enhanced membranous expression compared to adjacent normal breast tissue. The enhanced tumor staining is not associated with clinical variables like age of the patient or stage or subtype of the tumor, including Her2-status. CONCLUSION: These data suggest that EphB4 is a promising candidate for targeted image-guided surgery of breast cancer, especially for Her2 negative cases.

Exploration of tumour-infiltrating lymphocytes as a predictive biomarker for adjuvant endocrine therapy in early breast cancer.

PURPOSE: Tumour-infiltrating lymphocytes (TILs) have been shown to be prognostic for disease-free survival and predictive for the benefit of chemotherapy in patients with early breast cancer, but have not been studied for endocrine therapy. EXPERIMENTAL DESIGN: The number of CD8-positive TILs was assessed in a subcohort of 236 patients in the Intergroup Exemestane Study. AQ After 2-3 years of adjuvant tamoxifen, AQpatients were randomized between the schemes of continuation for 5 years on tamoxifen and switching to exemestane. The numbers of CD8-positive TILs were analysed for correlations with disease-free survival (DFS) and overall survival (OS). A similar analysis was performed on 2596 patients in the TEAM trial who were randomized between the sequential scheme and the exemestane monotherapy. RESULTS: In the first cohort, patients with low (below median) numbers of CD8-positive TILs had a univariate hazard ratio (HR) for DFS of 0.27 (95% CI 0.13-0.55) in favour of treatment with exemestane, whereas this benefit was not observed in patients with high numbers of CD8-positive TILs (HR 1.34, 95% CI 0.71-2.50, HR for interaction 5.02, p = 0.001). In the second cohort, patients with low numbers of CD8-positive TILs showed a benefit of exemestane treatment on recurrence-free survival (RFS HR 0.67, 95% CI 0.45-0.99), and not with above-median numbers of CD8-positive TILs (HR 0.86, 95% CI 0.59-1.26, HR for interaction 1.29, p = 0.36). CONCLUSIONS: This study is the first to propose the number of CD8-positive TILs as potential predictive markers for endocrine therapy, with the low presence of CD8-positive TILs associated to benefit for exemestane-inclusive therapy. However, treatment-by-marker interactions were only significant in one cohort, indicating the need for further validation.