Serum ferritin as a marker of therapeutic response in stage III and IV breast cancer.

Ferritin concentrations have been measured in serum from 266 patients receiving primary endocrine therapy for advanced breast cancer. Concentrations were significantly higher at presentation of advanced disease than in 55 tumour-free control patients. A positive correlation existed between increasing serum ferritin and tumour burden at presentation. A strong correlation was also found between therapeutic response and changes in serum ferritin (above 200 micrograms/l) in patients with distant metastases. More than one third of patients presenting with Stage IV disease developed concentrations in excess of 200 micrograms/l during initial treatment.