Can uterine fibroids ever progress to cancer?

No. The medical term for fibroids is leiomyomata. They are benign tumors that arise from smooth muscle cells; they do not become cancerous. The cancerous counterpart is called leiomyosarcoma. The problem is the inability to distinguish between the two without taking them out and looking at the cells under the microscope. Uterine tumors that enlarge quickly should be evaluated and possibly removed.