Management of malignant phaeochromocytoma: A retrospective review of the use of MIBG and chemotherapy in the West Midlands

Metastatic malignant phaeochromocytoma is a rare disorder, with no randomized and few prospective data to facilitate choice between the two main treatment modalities, chemotherapy and radiolabelled metaiodobenzylguanidine (MIBG). In the last decade the latter modality has been preferred and radiological response rates of 30% have been reported. There are fewer patients described in the literature who have received chemotherapy but one prospective trial of chemotherapy reported radiological response rates of 57%. A recent prospective trial combining the two modalities has been disappointing with only one patient completing the treatment schedule. We present six patients with malignant phaeochromocytoma or paraganglioma who received MIBG therapy. Four patients also received chemotherapy. A retrospective review of the case notes was performed. Radiological and hormonal responses were determined and the time to progression after each modality was calculated. One partial hormonal response was seen with MIBG treatment. One complete and one partial hormonal response and one partial radiological response were seen with chemotherapy. The median time to disease, progression from commencement of MIBG was 12 months (range 3-44) and from commencement of chemotherapy used as first or second line treatment was 22.5 months (range 7-25). Chemotherapy may be a more active modality in this disease than previously considered. MIBG uptake may increase after a partial radiological response to chemotherapy, enabling Subsequent MIBG therapy. Researchers carrying out future trials on combined therapy should consider administering chemotherapy prior to MIBG for the reasons that we outline in this article.