Hormone Receptors and Her2 Expression in Primary Tumor and Synchronous Axillary Lymph Node Metastasis in Estrogen Receptor Positive Breast Cancer.

e11580 Background: The receptor status, Estrogen Receptor (ER), Progesterone Receptor (PR) and HER-2 can change between the primary (P) and the synchronous axillary lymph node (ALN) metastases. The frequency of this change and its clinical significance is poorly known. We have investigated this situation in cases with ER positive BC. Methods: We retrospectively identified cases with ER positive, node positive non metastatic BC treated with surgery (lumpectomy or mastectomy plus ALN dissection) in two centres (Hospital Universitario Donostia and Onkologikoa) between 2001-2006. Specimens from the primary tumour and matched ALN were retrieved and tissue arrays were made to perform the inmunostaining for ER, PR and HER 2. HR was considered positive if at least 1% of the cells were stained. The intensity of the HR staining was grouped as negative (0%), low (1-10%), moderate (10-50%) and high ( > 50%. HER2 scoring was done following ASCO-CAP criteria (0, 1+,2+,3+). Clinical data were collected from the clinical record including: age, menopause status, T size, number of positive nodes, type of surgery, adjuvant therapy (chemo and hormone therapy and radiotherapy), recurrence and death. Results: 340 cases were identified and eventually 289 (85%) were analyzed. 284 were women, median age 59 years, 187 postmenopausal, and the median number of positive ALN was 2. All cases were ER + in the P and also in the matched ALN. The PR was positive in 92% of the P and 88% of the ALN. According to the intensity of staining groups the concordance between the P and ALN was 87% for the ER expression and 67% for the PR expression. HER2 was 3+ in 14 cases 4,8% of the primary and the concordance T/ALN was 94,7%. With a median follow up of 104 months, 66 (22,8%) has recurred, with an actuarial disease free survival of 64% and 67% breast cancer specific overall survival. No significant differences in DFS or OS were seen in discordant cases compared with concordant cases. Conclusions: The concordance in expression of receptors between the P and ALN in ER+BC is high for ER and HER2, being the PR the receptor with the highest rate of discordance although its clinical prognostic impact does not appear to be relevant.