Breast Neoplasms/diagnosis; Carcinoma, Ductal, Breast/diagnosis; Carcinoma, Intraductal, Noninfiltrating/diagnosis; Carcinoma, Lobular/diagnosis; Neoplasm Proteins/genetics; Neoplasm Recurrence, Local/diagnosis; Sentinel Lymph Node Biopsy; Uteroglobin/genetics; Axilla; Breast Neoplasms/genetics; Breast Neoplasms/metabolism; Carcinoma, Ductal, Breast/genetics; Carcinoma, Ductal, Breast/metabolism; Carcinoma, Intraductal, Noninfiltrating/genetics; Carcinoma, Intraductal, Noninfiltrating/metabolism; Carcinoma, Lobular/genetics; Carcinoma, Lobular/metabolism; Female; Follow-Up Studies; Humans; Immunoenzyme Techniques; Lymphatic Metastasis; Mammaglobin A; Middle Aged; Neoplasm Invasiveness; Neoplasm Proteins/metabolism; Neoplasm Recurrence, Local/genetics; Neoplasm Recurrence, Local/metabolism; Neoplasm Staging; Prognosis; Prospective Studies; RNA, Messenger/genetics; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Uteroglobin/metabolism