Long-term outcomes and failure patterns after laparoscopic intersphincteric resection in ultralow rectal cancers

Table 1 Patient basic characteristics, n (%)

Variables	Total (n = 368)	Local recurrence (n = 13)	Non-local recurrence (n = 355)	P value	Distant metastasis (n = 42)	Non-distant metastasis (n = 327)	P value
Age (yr)				0.746			0.325
≤ 60	184 (50)	5 (38.5)	179 (50.3)		18 (42.9)	167 (51.1)
> 60	184 (50)	8 (61.5)	176 (49.7)		24 (57.1)	160 (48.9)
Sex				0.855			0.179
Male	228 (62.0)	8 (61.5)	220 (61.9)		30 (71.4)	198 (60.7)
Female	140 (38.0)	5 (38.5)	135 (38.1)		12 (28.6)	128(39.3)
BMI (kg/m2)				0.845			0.503
≤ 25	246 (66.8)	8 (61.5)	238 (66.9)		30 (71.4)	217 (66.4)
> 25	122 (33.2)	5 (38.5)	117 (33.1)		12 (28.6)	110 (33.6)
Hb (g/L)				0.204			0.123
Normal	338 (91.8)	12 (92.3)	326 (91.8)		36 (85.7)	303 (92.7)
Abnormal	30 (8.2)	1 (7.7)	29 (8.2)		6 (14.3)	24 (7.3)
Alb (g/L)				0.756			0.058
≥ 35	353 (95.9)	12 (92.3)	341 (96.0)		38 (90.5)	316 (96.6)
< 35	15 (4.1)	1 (7.7)	14 (4.0)		4 (9.5)	11 (3.4)
CEA (ng/mL)				0.338			0.100
≤ 5	267 (72.6)	8 (61.5)	259 (72.9)		26 (61.9)	242 (74.0)
> 5	101 (27.4)	5 (38.5)	96 (27.1)		16 (38.1)	85 (26.0)
CA 19-9 (u/mL)				0.739			0.045
≤ 37	350 (95.1)	11 (84.6)	339 (95.5)		35 (83.3)	316 (96.6)
> 37	18 (4.9)	2 (15.4)	16 (4.5)		7 (16.7)	11 (3.4)
Tumor height from anal verge (cm)				0.985			0.053
≤ 4	273 (74.2)	10 (76.9)	243 (68.4)		26 (61.9)	248 (75.8)
> 4	95 (25.8)	3 (23.1)	112 (31.6)		16 (38.1)	79 (24.2)
Tumor size (mm)				0.465			0.590
≤ 40	250 (67.9)	7 (53.8)	243 (68.4)		27 (64.3)	224 (68.2)
> 40	118 (32.1)	6 (46.2)	112 (31.6)		15 (35.7)	103 (31.8)
(y)pT stage				0.198			< 0.001
1-2	166 (45.1)	4 (30.8)	162 (46.0)		8 (19.0)	158 (48.7)
3	202 (54.9)	9 (69.2)	193 (54.0)		34 (81.0)	168 (51.3)
Lymph node metastasis				0.001			< 0.001
No	245 (66.6)	3 (23.1)	242 (68.4)		16 (38.1)	230 (70.6)
Yes	123 (33.4)	10 (76.9)	113 (31.6)		26 (61.9)	96 (29.4)
(y)p TNM stage				0.001			< 0.001
0-II	245 (66.6)	3 (23.1)	242 (68.4)		16 (35.6)	231 (70.6)
III	123 (33.4)	10 (76.9)	113 (31.6)		26 (64.4)	95 (29.4)
ASA score				0.084			0.467
I-II	357 (97.0)	12 (92.3)	345 (97.5)		40 (95.2)	317 (97.2)
III	11 (3.0)	1 (7.7)	10 (2.5)		2 (4.8)	9 (2.8)
Differentiation				0.009			0.070
Well-moderate	328 (89.1)	8 (61.5)	320 (90.1)		34 (81.0)	294 (90.2)
Poor	40 (10.9)	5 (38.5)	35 (9.9)		8 (19.0)	32 (9.8)
Lymphovascular invasion				0.054			0.021
No	315 (85.6)	9 (69.2)	306 (86.4)		31 (73.8)	284 (87.2)
Yes	53 (14.4)	4 (30.8	49 (13.6)		11 (26.2)	42 (12.8)
Nerve invasion				0.093			0.012
No	327 (88.9)	9 (69.2)	318 (89.5)		32 (76.2)	295 (90.5)
Yes	41 (11.1)	4 (30.8)	37 (10.5)		10 (23.8)	31 (9.5)
nCRT				0.324			0.410
No	328 (89.1)	10 (76.9)	318 (89.6)		39 (92.9)	289 (88.7)
Yes	40 (10.9)	3 (23.1)	37 (10.4)		3 (7.1)	37 (11.3)
Adjuvant therapy				0.137			0.378
No	190 (51.6)	4 (30.8)	186 (52.5)		19 (45.2)	171 (52.5)
Yes	178 (48.4)	9 (69.2)	169 (47.5)		23 (54.8)	155 (47.5)

Alb: Serum albumin; BMI: Body mass index; CA: Cancer antigen; CEA: Carcinoembryonic antigen; Hb: Hemoglobin; nCRT: Neoadjuvant chemoradiotherapy; TNM: Tumor node metastasis; ASA: American Society of Anesthesiologists.

Table 2 Clinical demographics of the 13 patients who developed local recurrence

N	Age	Sex	BMI	(y)pT	(y)pN	AV	AT	nCRT	Adjuvant therapy	Recurrence location
1	46	Female	20.2	3	1b	2	4	No	Yes	Lateral and retroperitoneal lymph nodes
2	70	Female	23.6	3	2b	2	4	No	Yes	Axial
3	63	Male	25.5	1	2b	3	4.5	Yes	No	Lateral and retroperitoneal lymph nodes
4	65	Female	23.4	3	2b	2	4	No	Yes	Lateral and retroperitoneal lymph nodes
5	56	Male	18.0	2	0	1.5	3	No	No	Axial
6	69	Male	25.0	3	2a	3	5	No	Yes	Axial
7	35	Male	32.6	3	0	1.5	3	No	No	Axial
8	55	Male	22.8	3	1	2	4	No	No	Axial
9	66	Male	27.4	3	2b	2	4	No	Yes	Axial
10	64	Male	25.1	3	0	2	3	Yes	Yes	Axial
11	51	Female	22.2	3	2b	1.5	3	No	Yes	Lateral and retroperitoneal lymph nodes
12	82	Female	21.5	1	1b	3	5	No	Yes	Axial
13	50	Male	25.6	3	1	2	4	Yes	Yes	Axial

BMI: Body mass index; nCRT: Neoadjuvant chemoradiotherapy; AT: The height of tumor from anal verge; AV: The height of anastomotic stoma from anal verge.

Table 3 Univariate and multivariate analyses through Cox regression for overall survival

	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Age (>60/ ≤ 60 yr)	2.766	1.371–5.582	0.004	2.698	1.329–5.489	0.006
Sex (female/male)	0.713	0.359–1.415	0.333
BMI (> 25/≤ 25 kg/m2)	0.921	0.465–1.862	0.813
CEA (> 5/≤ 5 ng/mL)	1.350	0.690–2.639	0.381
Tumor size (> 40/≤ 40 mm)	1.425	0.742–2.733	0.287
Tumor height from anal verge (cm)	1.499	0.767–2.931	0.236
Lymphovascular invasion (yes/no)	1.768	0.808–3.867	0.154
Nerve invasion (yes/no)	2.596	1.186–5.683	0.017	1.501	0.660–3.414	0.332
(y)p T stage (3/1-2)	3.362	1.541–7.336	0.002	2.293	1.006–5.226	0.048
Lymph node metastasis (yes/no)	2.304	1.218–4.357	0.010	1.713	0.878–3.339	0.114
Differentiation (poor/well-moderate)	3.117	1.472–6.600	0.003	2.234	1.021–4.887	0.044
nCRT (yes/no)	0.525	0.126–2.185	0.376
Adjuvant therapy (yes/no)	1.176	0.622–2.224	0.617

BMI: Body mass index; CEA: Carcinoembryonic antigen; nCRT: Neoadjuvant chemoradiotherapy.

Table 4 Univariate and multivariate analyses through Cox regression for local recurrence-free survival

	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Age (> 60/ ≤ 60 yr)	1.318	0.442–3.931	0.620
Sex (female/male)	0.969	0.317–2.963	0.956
BMI (> 25/≤ 25 kg/m2)	1.263	0.413–3.860	0.683
CEA (> 5/≤ 5 ng/mL)	1.639	0.536–5.010	0.386
Tumor size (> 40/≤ 40 mm)	1.8332	0.615–5.451	0.277
Tumor height from anal verge (cm)	0.869	0.239–3.158	0.831
Lymphovascular invasion (yes/no)	2.897	0.889–9.436	0.077	1.056	0.287–3.884	0.935
Nerve invasion (yes/no)	2.812	0.771–10.258	0.117
(y)p T stage (3/1-2)	1.982	0.610–6.438	0.255
Lymph node metastasis (yes/no)	6.984	1.922–25.385	0.003	5.358	1.398–20.532	0.014
Differentiation (poor/well-moderate)	6.293	2.048–19.334	0.001	3.908	1.137–13.420	0.030
nCRT (yes/no)	2.731	0.750–9.940	0.127
Adjuvant therapy (yes/no)	2.357	0.726–7.653	0.154

BMI: Body mass index; CEA: Carcinoembryonic antigen; nCRT: Neoadjuvant chemoradiotherapy.

Table 5 Univariate and multivariate analyses through Cox regression for distal metastasis-free survival

	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Age (> 60/ ≤ 60 yr)	1.506	0.817–2.779	0.190
Sex (female/male)	0.597	0.305–1.168	0.132
BMI (> 25/≤ 25 kg/m2)	0.783	0.401–1.530	0.474
CEA (> 5/≤ 5 ng/mL)	1.577	0.846–2.940	0.152
Tumor size (> 40/≤ 40 mm)	1.685	0.779–3.642	0.185
Tumor height from anal verge (cm)	1.685	0.779–3.642	0.185
Lymphovascular invasion (yes/no)	2.527	1.263–5.055	0.009	1.128	0.508–2.506	0.767
Nerve invasion (yes/no)	3.061	1.499–6.252	0.002	1.644	0.745–3.628	0.218
(y)p T stage (3/1-2)	3.912	1.810–8.456	0.001	2.741	1.225–6.137	0.014
Lymph node metastasis (yes/no)	3.410	1.829–6.358	< 0.001	2.445	1.272–4.698	0.007
Differentiation (poor/well-moderate)	2.451	1.130–5.314	0.023	1.446	0.634–3.301	0.381
nCRT (yes/no)	0.718	0.222–2.326	0.581
Adjuvant therapy (yes/no)	1.299	0.708–2.386	0.398

BMI: Body mass index; CEA: Carcinoembryonic antigen; nCRT: Neoadjuvant chemoradiotherapy.