Final answer:
The most common sites of metastatic breast cancer recurrence are the bones and liver, with bones being the most frequent.
Step-by-step explanation:
Cancer cells from a primary tumor can metastasize and spread to different parts of the body through the bloodstream, forming new tumors called metastases. In breast cancer, the most common sites of recurrent metastatic disease are the bones, liver, lungs, and brain. Among these, bones are typically the most common site for metastasis, closely followed by the liver. The involvement of multiple sites is possible, and the stage of cancer would likely be classified as advanced if such metastases are present.