Long-term outcomes of endoscopic resection of 1-1.5 cm sized grade 1 rectal neuroendocrine tumor: A retrospective study

Table 1 Baseline characteristics, medians (Q1, Q3)/n (%)

	Study population (n = 1056)	≥ 0 cm and < 0.5 cm (n = 659)	≥ 0.5 cm and < 1 cm (n = 354)	≥ 1 cm and < 1.5 cm (n = 43)	P value
Age (years)	46 (38-54)	46 (38-54)	45 (37-55)	48 (38-61.5)	0.44
Sex					0.87
Male	636 (60.2)	401 (71)	209 (59)	26 (60.5)
Female	421 (39.8)	259 (29)	145 (41)	17 (39.5)
Rectal NET size (cm)	0.4 (0.3-0.6)	0.3 (0.2-0.4)	0.6 (0.5-0.7)	1.0 (1.0-1.1)	< 0.01
Distance from anal verge (cm)	7 (5-10)	7 (5-10)	8 (5-10)	6.5 (5-8)	0.13
Therapy methods					< 0.01
Endoscopic resection	932 (88.2)	621 (94.1)	284 (80.2)	27 (62.8)
Surgical resection	125 (11.8)	39 (5.9)	70 (19.8)	16 (37.2)
Endoscopic methods					< 0.01
ESD	180 (19.3)	67 (10.8)	100 (35.2)	13 (48.1)
EMR	752 (80.7)	554 (89.2)	184 (64.8)	14 (51.9)
Surgical methods					0.69
TEM	99 (79.2)	32 (82.1)	54 (77.1)	13 (81.3)
Transanalrectal resection	18 (14.4)	5 (12.8)	12 (17.1)	1 (6.3)
Lower anterior resection	8 (6.4)	2 (5.1)	4 (5.7)	2 (12.4)
WHO grade					0.02
Grade 1	627 (59.3)	401 (60.8)	194 (54.8)	32 (74.4)
Grade 2	19 (1.8)	7 (1.1)	12 (3.4)	0
Grade 3	0	0	0	0
Missing	411 (38.9)	252 (38.2)	148 (41.8)	11 (25.6)
Resection margin					0.57
Negative	1025 (97.0)	641 (97.1)	343 (96.9)	41 (95.4)
Positive	26 (2.5)	14 (2.1)	10 (2.8)	2 (4.6)
Uncheckable	6 (0.5)	5 (0.8)	1 (0.3)	0 (0)
Depth					< 0.01
1a	1014 (95.9)	660 (100.0)	353 (99.7)	1 (2.3)
1b	41 (3.9)	0 (0)	0 (0)	41 (95.4)
2	2 (0.2%)	0 (0)	1 (0.3)	1 (2.3)
Lymphovascular invasion					0.47
Absent/not identified	1040 (98.4)	648 (98.2)	350 (98.9)	42 (97.7)
Present	5 (0.5)	2 (0.3)	3 (0.9)	0 (0.0)
Missing	12 (1.1)	10 (1.5)	1 (0.2)	1 (2.3)

NET: Neuroendocrine tumor; ESD: Endoscopic submucosal dissection; EMR: Endoscopic mucosal resection; TEM: Transanal endoscopic microsurgery; WHO: World Health Organization.