Prophylactic lateral pelvic lymph node dissection in stage IV low rectal cancer

Table 1 Clinicopathological characteristics of the 50 patients

Variable
Age (yr)1	58.5 (31-78)
Sex
Male:female	43:7
Preoperative CEA level (ng/mL)1	24.5 (1.6–6856.5)
Tumor size (mm)1	63.0 (22–130)
T category
T2:T3:T4	2:31:17
Histopathological grading
G1:G2:G3	1:35:14
Lymphatic invasion
Absence:Presence	6:44
Venous invasion
Absence:Presence	10:40
Lymph node metastasis
Absence:Presence	9:41
Pathological LPLN metastasis
Absence:Presence	15:12
No. of metastatic organs
1:2:3	44:5:1
Metastatic organ
Liver:Lung:Peritoneum:Paraaortic LN:Bone	28:16:10:1:2
Grade of liver metastasis2
H1:H2:H3	14:5:9
Grade of lung metastasis2
LM1:LM2:LM3	8:7:1
Grade of peritoneal metastasis2
P1:P2:P3	8:1:1
Grade ≥ 3 Complication of primary tumor resection
Absence:Presence	38:12
Residual tumor status
R0:R2	20:30
Preoperative chemotherapy
Absence:Presence	41:9
Postoperative chemotherapy
Absence:Presence	7:43
Chemotherapy regimen
5FU-LV and/or S-1 and/or capecitabine	25
FOLFOX and/or CapeOX and/or FOLFIRI	33
Bevacizumab	18
Cetuximab or panitumumab	4

¹Data are expressed as median (range);

²Distant metastasis was classified according to the Japanese Society for Cancer of the Colon and Rectum classification (See material and method). FOLFOX oxaliplatin, leucovorin, and 5FU, CapeOX oxaliplatin and capecitabine, FOLFIRI irinotecan, leucovorin, and 5FU. CEA: Carcinoembryonic antigen; LPLN: Lateral pelvic lymph node; LN: Lymph node; TME: Total mesorectal excision; 5FU: 5-Fluorouracil; LV: Leucovorin.

Table 2 Clinicopathological characteristics of patients in the lateral pelvic lymph node dissection and total mesorectal excision groups

Variable	TME group (n = 23)	LPLND group (n = 27)	P value
Age (yr)
< 65	13	19	0.382
≥ 65	10	8
Sex
Male	20	23	0.999
Female	3	4
Preoperative CEA level (ng/mL)
< 20	10	11	0.999
≥ 20	13	16
Tumor size (mm)
< 60	7	8	0.999
≥ 60	16	19
T category
T2, 3	11	14	0.999
T4	12	13
Histopathological grading
G1, 2	19	17	0.206
G3	4	10
Lymphatic invasion
Absence	3	3	0.999
Presence	20	24
Venous invasion
Absence	7	3	0.155
Presence	16	24
Lymph node metastasis
Absence	7	2	0.062
Presence	16	25
No. of metastatic organs
1	21	23	0.647
2, 3	2	4
Metastatic organ
Liver only	12	13	0.999
Others	11	14
Grade ≥ 3 complication of primary tumor resection
Absence	17	21	0.999
Presence	6	6
Residual tumor status
R0	8	12	0.569
R2	15	15
Preoperative chemotherapy
Absence	18	23	0.715
Presence	5	4
Postoperative chemotherapy
Absence	4	3	0.689
Presence	19	24

CEA: Carcinoembryonic antigen; LPLND: Lateral pelvic lymph node dissection; TME: Total mesorectal excision.

Table 3 Univariate and multivariate analyses of different prognostic factors for overall survival

Variable	Modality	n	Univariate		Multivariate
			5-yr OS (%)	P value	HR (95%CI)	P value
Age (yr)	< 65	32	27.9	0.095	1
	≥ 65	18	14.8		1.5 (0.8–3.0)	0.197
Sex	Male	43	19.8	0.618
	Female	7	42.9
Preoperative CEA level (ng/mL)	< 20	21	23.7	0.671
	≥ 20	29	22.9
Tumor size (mm)	< 60	15	29.6	0.634
	≥ 60	35	20.9
T category	T2, 3	25	17.3	0.515
	T4	25	32.5
Histopathological grading	G1, 2	36	25	0.348
	G3	14	21.4
Lymphatic invasion	Absence	6	0	0.446
	Presence	44	24.2
Venous invasion	Absence	10	40	0.215
	Presence	40	19.1
Lymph node metastasis	Absence	9	0	0.904
	Presence	41	27.5
LPLND	Absence	23	17	0.523
	Presence	27	28.7
No. of metastatic organs	1	44	23.8	0.866
	2	6	22.2
Metastatic organ	Liver only	25	36	0.241
	Others	25	10.6
Grade ≥ 3 complication of primary tumor resection	Absence	38	28.8	0.398
	Presence	12	9.5
Residual tumor status	R0	20	59	< 0.001	1
	R2	30	3.6		2.1 (1.4–3.0)	< 0.001
Preoperative chemotherapy	Absence	41	17.6	0.254
	Presence	9	55.6
Postoperative chemotherapy	Absence	7	38.1	0.397
	Presence	43	24.3

OS: Overall survival; CEA: Carcinoembryonic antigen; LPLND: Lateral pelvic lymph node dissection.