Chromogranin A in a Cohort of Pheochromocytomas and Paragangliomas: Usefulness at Diagnosis and as an Early Biomarker of Recurrence.

OBJECTIVE

To evaluate the usefulness of chromogranin A (CgA) in the management of patients with pheochromocytomas (PHEOs) and paragangliomas (PGLs).

METHODS

We retrospectively reviewed the charts of 132 patients with confirmed PHEOs/PGLs (PPGLs) followed at our medical center. CgA was measured in 80 patients at diagnosis. The exclusion criteria removed 19 of these patients. Five patients with relapses were also analyzed.

RESULTS

Our cohort of 61 patients included 34 PHEOs, 14 head and neck PGLs, and 13 thoracoabdominal PGLs. CgA levels were elevated in 53 of 61 patients (86.9%) at diagnosis: 33 of 34 (97.1%) PHEOs, 9 of 14 (64.3%) head and neck paragangliomas, and 11 of 13 (84.6%) thoracoabdominal paragangliomas. For 8 of 13 (61.5%) nonfunctional PPGLs (5 head and neck paragangliomas and 3 thoracoabdominal paragangliomas), increased CgA levels showed potential as a tumor marker during follow-up. Of 10 patients with malignant PPGLs, only 1 had normal CgA levels (10.0%). Among 54 patients with PPGLs who underwent genetic testing, elevated CgA levels were positive in 73.7% of patients carrying a germline genetic variant (pathogenic and of unknown significance) versus 91.4% of patients without a known germline variant. We also report 5 PPGL cases with increased CgA levels as the first detectable marker of tumoral recurrence or progression preceding other biochemical markers or imaging.

CONCLUSION

CgA is a sensitive marker for the diagnosis of PHEO (97.1%) and thoracoabdominal paraganglioma (84.6%). CgA may be useful in the follow-up of nonfunctional PGLs and may also play a complementary role in the early detection of recurrence in secreting PPGLs.