Genetic Testing Referral Rates for Pheochromocytoma and Paraganglioma in an Academic Tertiary Centre.

Background: Clinical guidelines recommend genetic counselling for all patients with pheochromocytoma or paraganglioma (PPGL). Barriers to accessing genetics evaluation are incompletely understood. The objective of this study was to identify individual- and provider-level barriers to genetic testing.

Methods: Retrospective study of patients with PPGL who underwent resection at a tertiary academic centre. Study outcomes included referral rates for genetic counselling and completion of germline testing.

Results: Of 224 patients who underwent resection of PPGL, 75% were referred for genetic counselling, and 49% completed testing. Genetic testing was highest after 2019. More individuals 50 years or younger underwent testing compared to over 50 (65% vs. 37%, p < 0.001). Medicare insurance was associated with lower rates of testing compared to commercial insurances (32% vs. 64%, p = 0.006). Controlling for individual and temporal factors, head and neck paragangliomas were least likely to undergo genetic testing (OR 0.13, 95% CI: 0.05-0.31). Reasons for not undergoing testing included insurance denial, time constraints, and patient uncertainty. Twenty-two percent (14/68) of patients with pheochromocytoma had a positive finding (FH, MSH3, MUTYH, NF1, RET, SDHD and VHL), while 46% (19/41) of patients with paraganglioma had a positive finding (MSH6, SDHA, SDHB, SDHD, TMEM127 and VHL).

Conclusions: Germline testing was performed in less than half of patients with PPGL, and 30% who underwent tested carried a pathogenic mutation, reinforcing the importance of genetics evaluation. Older age, Medicare coverage, and head and neck paragangliomas were associated with lower rates of genetic testing, presenting opportunities to improve education and equity in the management of patients with PPGL.