Comparison of molecular subtypes between primary breast cancer and its metastatic axillary lymph node(s)
Abstract: Background Breast carcinoma primary tumors and synchronous axillary lymph node(s) metastases may represent different malignant clones, although the daily clinical practice depends only on the molecular subtypes of primary tumorto select the adjuvant systemic treatment.In some instances the absence of primary tumoror or presence of technical difficulties that prevent the identification of exact tumor subtypes in the primary mass mandate seeking for alternative to test , so our Aim was comparison of molecular subtypes between primary tumor &metastatic lymph node(s). Method In this prospective cohort study , 50 patients with node positive breast carcinoma included. Immunohistochemical analysis by using Envision method for detection of biomarkers: ER,PR,Her2/neu and Ki-67 to determine the four molecular subtypes then comparison between the primary tumor and its metastatic lymph node(s). Results :In this study there was 22 (44%) cases with luminal-A molecular subtype in both mass and lymph node, 21 (42%) cases with luminal-B in primary mass in comparison to 18 (36%) cases in their metastatic node,3(6%) cases with Her2/neu enriched in the primary mass in comparison to 6(12%) cases in its metastatic node.There was 4 (8%) cases with triple negative molecular subtype which had no difference between them.. In Conclusions: There is no statistically significant difference between primary tumor and its metastatic lymph node(s) this concordance regarding the molecular subtypesmay answer the question that pathologist can depends on the result of molecular subtypes on lymph node with good certainty if cannot do it on the primary tumor.