ABCG2 and metastatic malignant neoplasm in the lymph nodes: However, no significant correlation of genotype distributions of ABCG2 G34A, C421A polymorphisms was observed with other clinicopathological parameters (age at diagnosis, menopausal status, first-degree family history of cancer, tumor size, histology, lymph node metastasis, HER2 status, p53 status, BRCA1 status, and BRCA2 status).