Positive impact of genetic test on the management and outcome of patients with paraganglioma and/or pheochromocytoma

Context: Pheochromocytomas and paragangliomas (PPGLs) are characterized by a strong genetic component, with up to 40% of patients carrying a germline mutation in a PPGL susceptibility gene. International guidelines recommend that genetic screening be proposed to all patients with PPGL. Objective: Our objective was to evaluate how a positive genetic test impacts the management and outcome of patients with SDHx or VHL-related PPGL. Design: We performed a multicentric retrospective study involving 221 propositi carrying an SDHB, SDHD, SDHC, or VHL germline mutation. Patients were divided into two groups: Genetic patients, who were informed of their genetic status within the year following the first PPGL diagnosis, and historic patients, who only benefited from the genetic test several years after initial PPGL diagnosis. Results: Genetic patients had better follow-up than historic patients, with a greater number of examinations and a reduced number of patients lost to follow-up (9.6% vs 72%, respectively). During follow-up, smaller (18.7 vs 27.6 mm; P = 0.0128) new PPGLs and metastases as well as lower metastatic spread were observed in genetic patients. Of note, these differences were reversed in the historic cohort after genetic testing. Genetic patients who developed metachronous metastases had a better 5-year survival rate than historic patients (P = 0.0127). Conclusion: Altogether, our data suggest that early knowledge of genetic status had a positive impact on the management and clinical outcome of patients with a germline SDHx or VHL mutation.