[Achievements of the COMETE program in the genetics of pheochromocytoma]

Clinical and fundamental research based on the pheochromocytoma cohort of the COMETE network has drastically improved our knowledge of pheochromocytoma (PH). Previously, it was widely thought that only 10 % of PH patients had familial forms and that the malignant phenotype of PH could not be diagnosed before the first metastasis had already occurred. Genetic studies of the COMETE DNA collection contributed to showing that 25% to 30% of patients in fact have hereditary PH, due to a germline mutation of the SDHB, SDHD, VHL, RET or NF1 genes. The high-quality post-surgical clinical data collected by the COMETE network also show that SDHB germline mutations are a major risk factor for malignancy and poor outcome. Fundamental research work on the COMETE tumour collection shows that SDH genes are new tumour suppressor genes and that succinate dehydrogenase inactivation induces abnormal stimulation of the hypoxia-angiogenesis pathway. Since 2001, work by the COMETE network has led to new recommendations for genetic counselling and genetic testing in pheochromocytoma, and also for patient management. Finally, it has identified new molecular mechanisms involved in PH-related tumorigenesis.