Locally advanced pheochromocytoma exhibits metastatic behaviour

Locally advanced pheochromocytoma (LAP) comprises 9 percent of pheochromocytoma’s population and shows a metastatic behaviour, reveals a study, facilitating future pathological TNM classification.

In this retrospective multicentre study, the authors characterized LAP and recurrence-free survival (RFS) in 950 patients from 11 French referral centres. LAP was defined by capsular invasion, vascular invasion, adipose tissue invasion, and positive locoregional lymph nodes at diagnosis without evidence of distant metastasis.

Recurrence, the main outcome measure, was defined as tumour reappearance, including local site and distant metastasis. RFS was the primary endpoint, while secondary ones included overall survival (OS), characterization, and prognostic factors of recurrence.

Ninety patients (9 percent) had LAP criteria and 55 were eligible (median age 53 years, 61 percent males, 14 percent with germline mutation, and 84 percent with catecholamine excess). LAP was characterized by 31 (56 percent) capsular invasions, 27 (49 percent) fat invasions, six (11 percent) positive lymph nodes, and 22 (40 percent) vascular invasions.

Twelve patients (22 percent) had recurrences and three (5 percent) succumbed to metastatic disease after a median follow-up of 54 months (range, 6–180). Recurrences were local in two patients, distant in two, and both local and distant in eight. Median RFS was 115 months (range, 6–168), while median OS was not reached.

Multivariate analysis identified size >6.5 cm (p=0.019) and Ki-67 >2 percent (p=0.028) as significant prognostic factors.