Multivariate Cox regression analysis further found that PIK3CA rs2699887 GA/AA genotypes acted as protective prognostic factors (DFS: adjusted HR=0.384, 95% CI=0.170-0.867, P=0.021;OS: adjusted HR=0.192, 95% CI=0.059-0.619, P=0.006) adjusted by age, menopausal status, family history of BC, tumor size, clinical stages, lymph node metastasis, outlined in Table 3. This evidence concerns the gene PIK3CA and metastatic malignant neoplasm in the lymph nodes.