Clinical benefits of systemic chemotherapy for patients with metastatic pheochromocytomas or sympathetic extra-adrenal paragangliomas Insights from the largest single-institutional experience

BACKGROUND: The objective of this study was to evaluate the clinical benefits of systemic chemotherapy for patients with metastatic pheochromocytomas or sympathetic paragangliomas by assessing reductions in tumor size and blood pressure and improvements in overall survival (OS). METHODS: The authors retrospectively reviewed the medical records of patients with metastatic pheochromocytomas-sympathetic paragangliomas who had received chemotherapy at The University of Texas MD Anderson Cancer Center. RESULTS: Clinical benefit and OS were assessed. Of 54 patients who received chemotherapy, 52 patients were evaluable for response. Seventeen patients (33%) experienced a response, which was defined as decreased or normalized blood pressure/decreased number and dosage of antihypertensive medications and/or reduced tumor size after the first chemotherapy regimen. The median OS was 6.4 years (95% confidence interval [CI], 5.2-16.4 years) for responders and 3.7 years (95% CI, 3.0-7.5 years) for nonresponders. Among the patients who had synchronous metastatic disease, a positive response at 1 year after the start of chemotherapy was associated with a trend toward longer OS (log-rank test; P = .095). In a multivariate Cox proportional hazards model, the effect of response to chemotherapy on OS was significant (hazard ratio, 0.22; 95% CI, interval: 0.05-1.0; P = .05). All responders had received dacarbazine and cyclophosphamide. Vincristine was included for 14 responders, and doxorubicin was included for 12 responders. The clinical factors that predicted response to chemotherapy could not be identified. CONCLUSIONS: The current results indicted that chemotherapy may decrease tumor size and facilitate blood pressure control in approximately 33% of patients with metastatic pheochromocytoma-sympathetic paraganglioma. These patients exhibited longer survival. Cancer 2011. (c) 2011 American Cancer Society.