Altered Expression of RB and pRB in Tissue Arrays of Primary Breast Cancers and Matched Axillary Lymph Node Metastases.

Expression of pRB and E2F1 was significantly higher in LM than in primary BC. A majority of cancers with LM showed altered RB or pRB expression, suggesting that proteins downstream in the RB pathway play a critical role in metastatic BC and disease progression. So looking at the RB pathway could be an option for chemotherapy decisions in patients with only few LM.