A clinical prediction model to estimate the metastatic potential of pheochromocytoma/paraganglioma: ASES score

Background: Malignant pheochromocytoma and paraganglioma can be defined only after the development of metastases in nonchromaffin tissues. There is no single clinical parameter that is sufficiently reliable to predict metastatic potential, so our goal was to develop a prediction model based on multiple clinical parameters. Methods: The baseline age, size, extra-adrenal location, secretory type score was calculated in a retrospective cohort study comprising 333 patients with pheochromocytoma and paraganglioma. In each patient, each variable for age ≤35 years, tumor size ≥ 6.0 cm, extra-adrenal, and norepinephrine-secretory type was coded as 1 point (otherwise 0 point); these points were summed to yield age, size, extra-adrenal location, secretory type score. Results: Metastases occurred in 23 of 333 patients (6.9%). Metastatic pheochromocytoma and paraganglioma was associated with age ≤35 years (hazard ratio [HR] 2.74, 95% confidence interval [95% CI] 1.19–6.35), tumor size ≥6.0 cm (HR 2.43, 95% CI 1.06–5.56), extra-adrenal location (HR 2.73, 95% confidence interval 1.10–7.40), and tumor producing only norepinephrine (HR 2.96, 95% CI 1.30–6.76). The area under the curve of the age, size, extra-adrenal location, secretory type score was 0.735. There was a significant difference in metastasis-free survival between participants with age, size, extra-adrenal location, secretory type score ≥2 and score <2 (P <.0001 by the log rank test). The negative predictive value of this system was 96.5% for a cutoff point of 2. Conclusion: We developed a new prediction model, the age, size, extra-adrenal location, secretory type score, based on multiple clinical parameters to assess the metastatic potential of pheochromocytoma and paraganglioma.