Table 1. Clinical, Radiological, and Pathological Characteristics of Study Subjects with Noninvasive and Invasive NFPAs.

Variable	Subjects with non-invasive NFPAs (n=3)	Subjects with invasive NFPAs (n=11)	P value
Age, yr	33.3±14.6	41.8±10.1	0.503
Female sex	1 (33.3)	5 (45.5)	0.015
Maximal tumor size, cm	30.2±5.4	34.5±9.1	0.412
Clivus invasion	0	5 (45.5)	0.011
Regrowth after GTR	0	4 (36.4)	0.012
Ki-67 index >3%	0	5 (45.5)	0.011

Values are expressed as mean±standard deviation or number (%).

NFPA, nonfunctioning pituitary adenoma; GTR, gross total resection.