Is salvage surgery necessary for non-R0 endoscopic resection of small rectal neuroendocrine tumors?

Table 1 The characteristics of these 38 patients with non-R0 endoscopic resection

	Total (n = 38)
Age (year), mean ± SD	45.7 ± 13.6
Lesion size (mm), mean ± SD	7.2 ± 2.6
Gender (%)
Male	57.9 (22/38)
Female	42.1 (16/38)
Location (anus, %)
≤ 5 cm	42.1 (16/38)
6-10 cm	47.4 (18/38)
> 10 cm	10.5 (4/38)
Endoscopic resection method (%)
EMR	47.4 (18/38)
ESD	52.6 (20/38)
Positive margins (%)
Vertical	100.0 (38/38)
Lateral	0 (0/38)
Lymphovascular invasion (%)	0 (0/38)
Histologic grade (%)
G1	84.2 (32/38)
G2	15.8 (6/38)

EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection.

Table 2 The salvage surgery and follow-up data of these 38 patients with non-R0 endoscopic resection

	Total (n = 38)
Salvage surgery (%)
ESD	31.6 (12/38)
TEM	42.1 (16/38)
LAR	5.3 (2/38)
Follow-up only without salvage surgery	21.1 (8/38)
With endoscopic biopsy	37.5 (3/8)
Without endoscopic biopsy	62.5 (5/8)
Residual tumor cells (%)	0.0 (0/33)
Follow-up time (month), mean ± SD	46.4 ± 14.8
Recurrence (%)	0.0 (0/38)

ESD: Endoscopic submucosal dissection; TEM: Transanal endoscopic microsurgery; LAR: Low anterior resection.

Table 3 Comparison of these 38 patients with non-R0 endoscopic resection

	Salvage surgery group	Observation group	P value
n	30	8	/
Age (year), mean ± SD	46.8 ± 14.1	41.8 ± 9.8	0.32
Gender (male, %)	56.7 (17/30)	62.5 (5/8)	1.00
Lesion size (mm)	7.0 ± 2.6	8.1 ± 3.5	0.09
Endoscopic resection method (%)
EMR	36.7 (11/30)	87.5 (7/8)	0.02
ESD	63.3 (19/30)	12.5 (1/8)
Positive margins (%)
Vertical	100.0 (30/30)	100.0 (8/8)	1.00
Lateral	0 (0/30)	0 (0/8)
Lymphovascular invasion (%)	0 (0/30)	0 (0/8)	/
Histologic grade (%)
G1	80.0 (24/30)	100.0 (8/8)	0.31
G2	20.0 (6/30)	0.0 (0/11)
Follow-up time (month), mean ± SD	47.5 ± 13.2	41.9 ± 20.3	0.10
Recurrence (%)	0 (0/30)	0 (0/8)	/

EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection.