Response Following Surgical Resection of Malignant Pheochromocytoma and Paraganglioma: Can Postoperative Biochemical Remission Be Predicted?

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 37-82-Pheochromocytoma & Paraganglioma
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-56
Ryan Ellis*1, Dhaval Patel1, Tamara Prodanov2, Samira Sadowski1, Naris Nilubol1, Karen T Adams2, Karel Pacak3 and Electron Kebebew1
1National Cancer Institute, NIH, Bethesda, MD, 2Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 3National Institutes of Health (NIH), Bethesda, MD
Background

Aggressive surgical resection with intent to cure and surgical debulking procedures are commonly recommended in patients with malignant pheochromocytoma and paraganglioma. To date, there are no data on operative outcomes of patients after surgical resection of malignant pheochromocytoma and paraganglioma to determine if such an approach is appropriate and what factors may be associated with a good outcome.

Study Design

Retrospective analysis of 30 patients with malignant pheochromocytoma/paraganglioma who underwent surgical treatment. Clinical characteristics and genetic factors were analyzed as predictors of biochemical response to surgery, pharmacotherapy changes, disease-free interval, and overall survival.

Results

Thirty patients underwent a total of 42 operations with a median follow-up time of 24 months (range, 1 to 114). Complete disease resection (R0/R1) was achieved in 18 (42.9%) cases, while 24 cases (57.1%) were debulking (R2) procedures without intent to cure.  Overall survival in the cohort was 86.7%. Complete biochemical remission was achieved in 10 (23.8%) cases and partial biochemical response was achieved in 23 (54.8%) cases. Patients with disease confined to the abdomen were more likely to achieve and maintain a biochemical response postoperatively than those with extra-abdominal disease (P = 0.0003). Debulking operations were significantly less likely to achieve or maintain biochemical palliation, with only 1 patient maintaining a biochemical response 12 months postoperatively (P < 0.0001). Patients were also less likely to obtain pharmacologic independence following debulking (P = 0.0003), with only 2 (8.3%) not requiring pharmacotherapy six months after the intervention. Factors not associated with biochemical response to surgery include gender, family history, SDHB mutation status, adjuvant therapy, and preoperative biochemical profile.

Conclusions

Depending on the extent of disease, patients with malignant pheochromocytoma/paraganglioma can benefit from operative intervention and resection with intent to cure. Patients with disease confined to the abdomen at the time of resection are more likely to achieve biochemical palliation and disease remission. Debulking procedures are unlikely to achieve clinically significant biochemical response, with any biochemical response achieved being very short-lived.

Nothing to Disclose: RE, DP, TP, SS, NN, KTA, KP, EK

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Supported by the Intramural Research Program of the Center for Cancer Research, National Cancer Institute, NIH.