Table 4.

The impact of lymph node parameters (numbers and ratio) on overall survival in a Cox multivariate model

SEER	≤5 lymph nodes	p value	6–12 lymph nodes	p value	≥13 lymph nodes	p value
Numbers of positive lymph nodes, HR (95 % CI)
No positive node	Reference category
One positive node	NS	–	1.46 (1.11–1.92)	0.007	1.09 (0.77–1.53)	0.637
Two positive nodes	NS	–	1.24 (0.9–1.71)	0.196	1.44 (1.03–2.01)	0.032
Three or more positive nodes	NS	–	1.62 (1.23–2.14)	<0.001	1.72 (1.33–2.24)	<0.001
Lymph node ratio, HR (95 % CI)
LNR=0	Reference category
LNR<0.2	NS	–	1.3 (1–1.17)	0.048	1.28 (0.9–1.67)	0.071
LNR, 0.2–0.3	NS	–	1.5 (1.03–2.18)	0.035	1.6 (1.14–2.25)	0.007
LNR≥0.3	NS	–	1.69 (1.29–2.23)	<0.001	2.27 (1.67–3.08)	<0.001
Single institution (MGH)	≤9 lymph nodes	p value	10–16 lymph nodes	p value	≥17 lymph nodes	p value
Numbers of positive lymph nodes, HR (95 % CI)
No positive node	Reference category
One positive node	1.56 (0.98–2.48)	0.058	1.25 (0.80–1.96)	0.326	1.27 (0.55–2.92)	0.56
Two positive nodes	1.72 (1.05–2.79)	0.028	2.47 (1.53–4.00)	<0.001	1.38 (0.69–2.76)	0.36
Three or more positive nodes	2.54 (1.55–4.18)	<0.001	2.03 (1.38–2.99)	<0.001	2.36 (1.34–4.18)	0.002
Lymph node ratio, HR (95 % CI)
LNR=0	Reference category
LNR<0.2	1.42 (0.85–2.41)	0.183	1.95 (1.31–2.88)	0.001	2.70 (1.47–4.95)	<0.001
LNR, 0.2–0.3	1.29 (0.66–2.53)	0.461	2.10 (1.29–3.43)	0.003	2.18 (1.02–4.65)	0.044
LNR≥0.3	2.07 (1.36–3.15)	0.001	1.85 (1.14–2.99)	0.012	4.95 (2.47–9.92)	<0.001

CI confidence interval, HR hazard ratio, NS not significant

Age, gender, race/ethnicity, year of diagnosis, size, grade, and T stage of tumor were used as covariates in separate Cox models for each lymph node variable