A composition comprising a monoclonal antibody that specifically binds to human progastrin for use in preventing or preventing recurrence or treating progastrin sensitive breast cancer, wherein said antibody comprises: • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:1, CDR2 comprises the amino acid sequence of SEQ ID NO:2, and CDR3 comprises the amino acid sequence of SEQ ID NO:3, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:4, CDR2 comprises the amino acid sequence of SEQ ID NO:5, and CDR3 comprises the amino acid sequence of SEQ ID NO:6; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:37, CDR2 comprises the amino acid sequence of SEQ ID NO:41, and CDR3 comprises the amino acid sequence of SEQ ID NO:45, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:49, CDR2 comprises the amino acid sequence of SEQ ID NO:52, and CDR3 comprises the amino acid sequence of SEQ ID NO:55; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:38, CDR2 comprises the amino acid sequence of SEQ ID NO:42, and CDR3 comprises the amino acid sequence of SEQ ID NO:46, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:50, CDR2 comprises the amino acid sequence of SEQ ID NO:53, and CDR3 comprises the amino acid sequence of SEQ ID NO:56; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:39, CDR2 comprises the amino acid sequence of SEQ ID NO:43, and CDR3 comprises the amino acid sequence of SEQ ID NO:47, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:50, CDR2 comprises the amino acid sequence of SEQ ID NO:53, and CDR3 comprises the amino acid sequence of SEQ ID NO:57; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:40, CDR2 comprises the amino acid sequence of SEQ ID NO:44, and CDR3 comprises the amino acid sequence of SEQ ID NO:48, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:51, CDR2 comprises the amino acid sequence of SEQ ID NO:54, and CDR3 comprises the amino acid sequence of SEQ ID NO:58. • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:1, CDR2 comprises the amino acid sequence of SEQ ID NO:2, and CDR3 comprises the amino acid sequence of SEQ ID NO:3, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:4, CDR2 comprises the amino acid sequence of SEQ ID NO:5, and CDR3 comprises the amino acid sequence of SEQ ID NO:6; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:37, CDR2 comprises the amino acid sequence of SEQ ID NO:41, and CDR3 comprises the amino acid sequence of SEQ ID NO:45, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:49, CDR2 comprises the amino acid sequence of SEQ ID NO:52, and CDR3 comprises the amino acid sequence of SEQ ID NO:55; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:38, CDR2 comprises the amino acid sequence of SEQ ID NO:42, and CDR3 comprises the amino acid sequence of SEQ ID NO:46, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:50, CDR2 comprises the amino acid sequence of SEQ ID NO:53, and CDR3 comprises the amino acid sequence of SEQ ID NO:56; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:39, CDR2 comprises the amino acid sequence of SEQ ID NO:43, and CDR3 comprises the amino acid sequence of SEQ ID NO:47, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:50, CDR2 comprises the amino acid sequence of SEQ ID NO:53, and CDR3 comprises the amino acid sequence of SEQ ID NO:57; or • a heavy chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:40, CDR2 comprises the amino acid sequence of SEQ ID NO:44, and CDR3 comprises the amino acid sequence of SEQ ID NO:48, and a light chain variable region in which CDR1 comprises the amino acid sequence of SEQ ID NO:51, CDR2 comprises the amino acid sequence of SEQ ID NO:54, and CDR3 comprises the amino acid sequence of SEQ ID NO:58.