Lymph node harvest in colon and rectal cancer: Current considerations

Table 1 Observed overall 5-year survival rates by stage for colonic and rectal cancer

Rectum		Colon
TN	SEER- observed 5 year overall survival %	TN	SEER- observed 5 year overall survival %
T1
N0	81.4	N0	78.7
N1	72.1	N1a	73.7
N2a	73.8	N1b	67.2
N2b	53.2	N2a	64.7
		N2b	51.8
T2
N0	75.7	N0	74.3
N1	72.1	N1a	73.7
N2a	58.2	N1b	67.2
N2b	41.7	N2a	64.7
		N2b	51.8
T3
N0	64.0	N0	66.7
N1a	55.4	N1a	58.2
N1b	49.7	N1b	51.7
N2a	42.5	N2a	42.8
N2b	32.0	N2b	30.4
T4a
N0	55.7	N0	60.6
N1a	53.2	N1a	52.2
N1b	43.9	N1b	42.1
N2a	44.3	N2a	32.5
N2b	24.5	N2b	17.5
T4b
N0	44.7	N0	45.7
N1	24.3	N1a	30.6
N2a	18.5	N1b	25.4
N2b	12.3	N2a	18.3
		N2b	12.9

Taken from American Joint Committee on Cancer cancer staging manual 2009, Gunderson et al[12,13]. Nodal involvement: N0 - no involvement; N1 - 1-3 positive lymph nodes (LNs); N1a - 1 positive LN; N1b - 2-3 positive LN; N1c - tumor deposit(s) in the subserosa, mesentery or non-peritonealized pericolic or perirectal tissues without regional nodal metastases; N2- 4 or more positive LN; N2a- 4-6 positive LN; N2b- seven or more positive LN. SEER: Surveillance, Epidemiology and End Results.

Table 2 Survival in stage II colorectal cancer with increasing lymph nodes

Authors	Study/country	Tumor location	No. of patients	LN cut-off parameters	5-year survival %	Significance
Observational studies
Caplin et al[14]	Switzerland	Colorectal	222	≤ 6	492	P = 0.0014
				≥ 7	682
Tepper et al[16]	National intergroup trial (United States)	Rectum	1664	< 5	642	P = 0.0081
				≥ 5 and < 9	632	P = 0.041
				≥ 9 and < 14	612	P = 0.021
				≥ 14	672
Cianchi et al[17]	Italy	Colorectal	140	≤ 8	54.92	P < 0.001
				> 9	79.92
Prandi et al[20]	National intergroup for Adjuvant Therapy on Colon Cancer (INTACC, Italy)	Colon	3648	0-7	81; 663	P trend = 0.00092
				8-12	812; 743	P trend < 0.00013
				13-17	872; 773
				≥ 18	892; 833
Law et al[22]	Canada	Colon	115	≤ 6	622	P = 0.03
				≥ 7	862
Le Voyer et al[23]	Intergroup Trial INT-0089 (United States)	Colon	3411	≤ 10	732; 804; 723	P < 0.00012
				11-20	802; 854;793	P = 0.154
				> 20	872; 924; 823	P = 0.10953
Tsai et al[28]	Taiwan	Colorectal	180	< 18	Percentage survival not stated	P = 0.015
				≥ 18	Percentage survival not stated
Vather et al[30]	New Zealand Cancer Registry (NZCR)	Colon	1945	Decreasing mortality with increasing lymph nodes. Greatest statistical difference between ≤ 12 and >12 nodes		P = 0.0001
Choi et al[31]	Hong Kong	Colorectal	664	< 21	603	P = 0.001
				≥ 21	803
Multicenter observational study
Swanson et al[24]	National cancer database (NCD, United States)	Colon	31 515	1-7	49.82	P < 0.0001
				8-12	56.22
				≥ 13	63.42

¹Compared with patients with ≥ 14 lymph nodes (LNs) examined;

²Overall survival;

³Disease free survival;

⁴Cause specific survival.

Table 3 Mean number of lymph nodes associated with age and tumor location

	No. of cases	No. of lymph nodes (mean ± SD)
Age (yr)
≤ 50	40	18.2 ± 12.6
> 50 and ≤ 60	82	17.8 ± 9.5
> 60 and ≤ 70	109	14.4 ± 8.0a
> 70 and ≤ 80	117	15.1 ± 7.2a
> 80	82	14.9 ± 7.4a
Location
Cecum/ ascending colon	161	17.8 ± 7.9c
Transverse colon	22	14.5 ± 7.0
Descending colon	15	19.0 ± 12.5
Sigmoid colon	167	14.3 ± 9.4
Rectum	69	13.7 ± 6.6

^aP = 0.002 vs age ≤ 60 years;

^cP < 0.001 and P = 0.001 vs tumors from sigmoid colon and rectum, respectively.

Table 4 Survival by lymph node ratio in stage III colorectal cancer

Authors	Study/country	Tumor location	No. of patients	Lower cut off LNR	5-year survival %	Significance
Observational study
Lee et al[68]	South Korea	Colon	201	0.01-0.11	83.64	P < 0.0001
				0.12-0.24	61.14
				0.25-0.92	204
Schumacher et al[69]	United States	Colon	75	< 0.18	8541	P < 0.005
				≥ 0.18	5041
Peschaud et al[73]	France	Rectum	307	0.01-0.07	794; 9232	P = 0.0064
				> 0.2	424; 6632	P = 0.00033
Park et al[71]	South Korea	Colon	318	< 0.059	83.642	P = 0.002
				0.059-0.23	71.142
				> 0.23	5542
Rosenberg et al[74]	Germany	Colorectal	3026	0.01-0.17	60.63	P < 0.001
				0.18-0.41	34.43
				0.42-0.69	17.63
				> 0.70	5.33
Multicenter observational study
De Ridder et al[67]	SEER cancer registry (Belgium)	Colon	26 181	≤ 0.4	565	P < 0.0001
				≥ 0.4	255
Wang et al[70]	SEER cancer registry (United States)	Colon (stage IIIB)	14 644	< 1/14	63.53	P < 0.0001
				1/14-0.25	54.73
				0.25-0.50	44.43
				0.50-1.0	34.23
	SEER cancer registry (United States)	Colon (stage IIIC)	7658	< 1/14	Not estimated	P < 0.0001
				1/14-0.25	49.63
				0.25-0.50	41.73
				0.50-1.0	25.23
Rosenberg et al[75]	Munich Cancer Registry (MCR, Germany)	Colorectal	27 803	0	71.43	P < 0.001
				0.01-0.17	52.43
				0.18-0.41	33.33
				0.42-0.69	19.83
				> 0.70	8.33

¹Approximate figures taken from graph in report. Exact 5-yar survival by lymph node ratio (LNR) not stated in report;

²3-year survival, Surveillance, Epidemiology, and End Results (SEER);

³Overall survival;

⁴Disease free survival;

⁵Cause specific survival.

Table 5 Survival in patients with negative lymph nodes after pre-operative chemoradiotherapy

Lymph nodesretrieved	No. of patients	Overall survival		Disease-free survival
		%	P	%	P
< 4	22	95		76
> 4	176	81	0.42	70	0.47
< 5	31	85		67
> 5	167	82	0.71	72	0.73
< 6	45	85		66
> 6	153	82	0.89	73	0.56
< 7	58	84		64
> 7	140	82	0.68	75	0.37
< 8	79	83		66
> 8	119	83	0.53	75	0.38
< 9	88	84		69
> 9	110	81	0.88	73	0.62
< 10	101	86		72
> 10	97	79	0.58	70	0.65
< 11	109	87		74
> 11	89	77	0.27	68	0.43
< 12	117	87		74
> 12	81	76	0.36	68	0.36
< 13	129	87		74
> 13	69	73	0.25	65	0.26

Showed no significant difference in 5-year overall survival and disease-free survival when increasing lymph nodes were harvested (Rullier et al[7]).