Table 4. Association of the individual parameters of the GAPP at the initial operation with occurrence of metastasis.

GAPP parameters	Univariate		Multivariate
	HR (95% CI)	P	HR (95% CI)	P
Histological pattern
Zellballen	Ref		Ref
Large and irregular cell nest or pseudorosette (even focal)	4.11 (1.16–14.61)	0.029	7.00 (1.23–39.89)	0.029
Comedo-type necrosis	64.08 (7.25–566.26)	<0.001	NA	0.891
Cellularity
Low (<150 cells/U)	Ref		Ref
Moderate (150–250 cells/U)	1.08 (0.36–3.24)	0.890	1.04 (0.22–4.90)	0.965
High (>250 cells/U)	2.58 (0.52–12.89)	0.248	0.26 (0.02–3.00)	0.281
Ki67 labeling index (%)
<1	Ref		Ref
1–3	2.63 (0.67–10.31)	0.167	10.70 (1.77–64.68)	0.010
>3	9.25 (2.16–39.52)	0.003	4.22 (0.66–27.07)	0.128
Vascular or capsular invasion	3.01 (0.85–10.69)	0.089	1.18 (0.26–5.30)	0.830
Catecholamine type
Non-functioning or adrenergic type	Ref		Ref
Noradrenergic type	3.89 (1.33–11.39)	0.013	1.44 (0.29–7.23)	0.660

CI, confidence interval; GAPP, Grading system for Adrenal Pheochromocytoma and Paraganglioma; HR, hazard ratio; NA, not applicable; PPGL, pheochromocytoma and paraganglioma.

If the UMN levels were high, with or without elevated UNM levels, the catecholamine type was adrenergic type. If the UNM levels were high, without elevated UMN levels, the catecholamine type was noradrenergic type.

Significant results (P < 0.05) are in bold.