I have recently been diagnose with idc er+pr+; fortunatelly the tumor is very little (4 mm or less), may I take bee propolis for inmunity? .

You may. I do not have any information that this has been used in clinical trials of breast cancer, specifically, but bee propolis has been shown to have anti cancer activity in breast cancer cells in the laboratory. In short, it is of unproven benefit, but is unlikely to harm you.
Doubt it helps any. You do not need anything more done as tumors this small rarely if ever cause a probelm in the future. We have no good medicines to increase your immunity which is probably normal anyway.