Is stage 3c breast cancer curable?

Yes: ...In theory, with aggressive multi modality therapy (surgery plus chemo plus radiation +/- hormones +/- herceptin). The risk of relapse is high but you do all you can and hope for the best. If this is about you, fight well and best wishes.

Yes.: Stage 3c can be cured, usually with surgery, radiation, and chemotherapy. There are new targeted agents that have improved this, based on "targeting" the treatment to the type of breast cancer. Unfortunately, recurrence, even in the form of metastases, can occur at any time so patients need to be followed, and can't really be declared "cured".