Long-term outcomes after endoscopic removal of malignant colorectal polyps: Results from a 10-year cohort

Table 1 Characteristics of endoscopically removed malignant colorectal polyps, n = 135

Characteristic	n	Value
Location, n (%)
Colon	80 (59)
Right colon	12 (9)
Left colon	68 (50)
Rectum	55 (41)
Morphology (Paris classification), n (%)
Pedunculated
0-Ip	65 (48)
Non-pedunculated	60 (45)
0-Is	34 (25)
0-Isp	3 (2)
0-IIa	13 (10)
0-IIb	3 (2)
0-IIc	7 (5)
Not available	10 (7)
Polyp size in mm, mean (95%CI)	22.1 (20.0–24.2)
Pedunculated	20.7 (18.0–23.4)	P = 0.0041
Non-pedunculated	24.6 (21.0–28.2)
En bloc resection, n (%)	89 (66)
Pedunculated	53 (82)
Non-pedunculated	28 (47)
Polyp morphology not available	8

¹Mann-Whitney test.

CI: Confidence interval.

Table 2 Risk factors for residual malignancy and lymph node involvement detected at secondary surgery: Univariate analysis

Investigated parameter	Residual malignancy		Lymph node involvement
	OR	P value	OR	P value
Size	0.05	0.055	0.003	0.936
Location: Rectum	1.10	0.148	1.34	0.268
Morphology: Non-pedunculated	1.74	0.116	17.90	0.995
En bloc resection: No	1.74	0.042	1.10	0.362
Tumor differentiation	NA		NA
Positive resection margins: Negative-R1	17.60	0.998	17.20	0.998
Positive resection margins: Negative-critical	3.58E-08	1.000	-6.93E-09	1.00
Depth of submucosal invasion: Deep	-1.18	0.227	-0.32	0.773
Lymphatic invasion	2.40	0.173	-17.80	0.997
Vascular invasion	-16.96	0.997	-16.06	0.997
Tumor budding	5.17E-15	1.000	-16.62	0.998

NA: Not available; OR: Odds ratio.

Table 3 Risk factors for residual malignancy and lymph node involvement detected at secondary surgery: Multivariate analysis

Investigated parameter	Residual malignancy		Lymph node involvement
	OR	P value	OR	P value
Size	0.04	0.179	-0.02	0.654
Location: Rectum	0.48	0.602	0.82	0.518
Morphology: Non-pedunculated	1.32	0.332	17.45	0.996
En bloc resection: No	0.81	0.409	0.96	0.477
At least one high-risk feature	17.7	0.994	-0.48	1

OR: Odds ratio.

Table 4 Adverse outcome rates in the patient groups, n (%)

Feature	Secondary surgery for completion, n = 36	Surveillance-only strategy, n = 75	P value
Adverse outcomes: Dissemination and/or local recurrence	5 (13.9)	5 (6.7)	0.289
Dissemination	5 (13.9)	4 (5.3)	0.147
Local recurrence	2 (5.6)	2 (2.7)	0.594
Both	2 (5.6)	1 (1.3)
Tumor progression	1 (2.8)	1 (1.3)	0.546

Table 5 Risk factors for long-term adverse outcomes: Univariate analysis

Investigated parameter	Distant metastasis		Local recurrence
	OR	P value	OR	P value
Size	0.03	0.278	0.001	0.985
Location: Rectum	0.70	0.276	1.35	0.251
Morphology: Non-pedunculated	2.51	0.020	18.30	0.995
En bloc resection: No	0.19	0.776	-0.55	0.641
Tumor differentiation	-13.16	0.993	NA
Positive resection margins: Negative-R1	0.43	0.715	1.75E-14	1.000
Positive resection margins: Negative-critical	-17.26	0.995	-8.97E-30	1.000
Depth of submucosal invasion: Deep	-0.486	0.578	-17.41	0.995
Lymphatic invasion	-16.62	0.995	-7.37E-14	1.000
Vascular invasion	1.70	0.212	5.19E-15	1.000
Tumor budding	-17.17	0.997	NA
Surgery for completion: No	-0.61	0.343	-0.429	0.677

NA: Not available; OR: Odds ratio.

Table 6 Risk factors for long-term adverse outcomes: Multivariate analysis

Investigated parameter	Distant metastasis		Local recurrence
	OR	P value	OR	P value
Size	-0.02	0.572	1.26E-15	1.000
Location: Rectum	0.32	0.648	19.5	0.998
Morphology: Non-pedunculated	1.19	0.136	17.7	0.998
At least one high-risk feature	0.59	0.514	18.0	0.999
Surgery for completion	-0.39	0.613	-19.4	0.998

OR: Odds ratio.

Table 7 Long-term outcomes in view of the current National Comprehensive Cancer Network recommendations

Recommendation according to NCCN guideline	Surgery for completion, n = 70		Surveillance was sufficient, n = 41
Resection was performed?	Yes	No	Yes	No
	33	37	3	38
Adverse outcome: Dissemination or local recurrence	5 (15)	2 (5.4)	0	3 (7.9)
Dissemination	5	2	0	2
Local recurrence	2	0	0	2

Data are n or n (%). NCCN: National Comprehensive Cancer Network.