Medical records and health information technicians also may specialize in cancer registry. Cancer (or tumor) registrars maintain facility, regional, and national databases of cancer patients. Registrars review patient records and pathology reports, and assign codes for the diagnosis and treatment of different cancers and selected benign tumors. Registrars conduct annual followups to track treatment, survival, and recovery. This information is used to calculate survivor rates and success rates of various types of treatment, to locate geographic areas with high incidences of certain cancers, and to identify potential participants for clinical drug trials.