M. Colleen Sullivan, CRNP Colleen Sullivan is a CRNP, who specializes in breast cancer, general cancer, chemotherapy, gastrointestinal cancer, neutropenia, and supportive oncology care. Colleen attended University of Pittsburgh School of Nursing and is board certified: American Nurses Credentialing Center. She sees patients at Wexford H+W Pavilion in Wexford, PA.