Development and validation of a nomogram to predict liver metastasis in patients with pancreatic ductal adenocarcinoma: a large cohort study

Figures & data

Table 1 The comparison of demographic and clinicopathological factors between training cohort and validation cohort

Characteristic		Whole cohort	Training cohort	Validation cohort	P-value	Training cohort				Validation cohort
						Liver metastasis		N	P-value	Liver metastasis		N	P-value
Absent	Present	Absent	Present
		12,644	9,483	3,161		8,276	1,207	9,483		2,721	440	3,161
Age	≤65	5,769	4,314	1,455	0.606	3,741	573	4,314	0.146	1,244	211	1,455	0.410
>65	6,875	5,169	1,706	4,535	634	5,169	1,477	229	1,706
Gender	Femal	6,215	4,722	1,493	0.013	4,197	525	4,722	<0.001	1,307	186	1,493	0.027
Male	6,429	4,761	1,668	4,079	682	4,761	1,414	254	1,668
Tumor site	Head	9,197	6,900	2,297	0.995	6,295	605	6,900	<0.001	2,065	232	2,297	<0.001
	Body	1,740	1,304	436		1,028	276	1,304		347	89	436
Tail	1,707	1,279	428	953	326	1,279	309	119	428
Tumor grade	Well	1,346	1,013	333	0.851	959	54	1,013	<0.001	312	21	333	<0.001
	Moderate	5,476	4,123	1,353		3,667	456	4,123		1,190	163	1,353
Poor	5,822	4,347	1,475	3,650	697	4,347	1,219	256	1,475
Tumor size (cm)	≤2	1,341	1,017	324	0.330	953	64	1,017	<0.001	292	32	324	<0.001
	2~4	6,733	5,014	1,719		4,469	545	5,014		1,532	187	1,719
>4	4,570	3,452	1,118	2,854	598	3,452	897	221	1,118
T stage*	I	1,236	952	284	0.333	902	50	952	<0.001	258	26	284	<0.001
	II	5,800	4,324	1,476		3,884	440	4,324		1,324	152	1,476
	III	3,359	2,532	827		2,071	461	2,532		657	170	827
IV	2,249	1,675	574	1,419	256	1,675	482	92	574
LN metastasis	Absent	6,409	4,826	1,583	0.455	4,330	496	4,826	<0.001	1,409	174	1,583	<0.001
Present	6,235	4,657	1,578	3,946	711	4,657	1,312	266	1,578
N stage*	N0	1,972	1,494	478	0.246	1,397	97	1,494	<0.001	449	29	478	<0.001
	N1	3,189	2,421	768		2,299	122	2,421		728	40	768
N2	7,483	5,568	1,915	4,580	988	5,568	1,544	371	1,915
Lung metastasis	Absent	12,241	9,181	3,060	0.999	8,150	1,031	9,181	<0.001	2,683	377	3,060	<0.001
Present	403	302	101	126	176	302	38	63	101
Bone metastasis	Absent	12,523	9,392	3,131	0.993	8,245	1,147	9,392	<0.001	2,710	421	3,131	<0.001
Present	121	91	30	31	60	91	11	19	30
Brain metastasis	Absent	12,632	9,473	3,159	0.742	8,271	1,202	9,473	0.005	2,721	438	3,159	0.019
	Present	12	10	2	5	5	10	0	2	2

Note: *Based on the 8thTNM stage classification.

Abbreviation: LN, lymph node.

Table 2 Univariate and multivariate logistic analyses of liver metastasis in patients PDAC

Characteristic		Model 1						Model 2
		Univariate analysis			Multivariate analysis			Univariate analysis			Multivariate analysis
OR	95% CI	P-value	OR	95%CI	P-value	OR	95% CI	P-value	OR	95% CI	P-value
Age (years)	≤65/>65	0.857	0.766–0.959	0.007	0.794	0.675–0.934	0.005	0.857	0.766–0.959	0.007	0.768	0.650–0.907	0.002
Gender	Female/male	1.310	1.171–1.467	<0.001	1.225	1.042–1.441	0.014	1.310	1.171–1.467	<0.001	1.228	1.041.450	0.015
Tumor site	Head/body/tail	2.119	1.972–2.277	<0.001	1.816	1.642–2.008	<0.001	2.119	1.972–2.277	<0.001	1.714	1.545–1.902	<0.001
Tumor grade	Well/moderate/poor	1.730	1.586–1.888	<0.001	1.697	1.500–1.921	<0.001	1.730	1.586–1.888	<0.001	1.660	1.464–1.883	<0.001
Tumor size (cm)	≤2/2–4/>4	1.911	1.737–2.101	<0.001	1.471	1.221–1.771	<0.001	1.911	1.737–2.101	<0.001	1.422	1.177–1.719	<0.001
T stage*	T1/T2/T3/T4	1.520	1.421–1.626	<0.001	1.109	0.973–1.264	0.121	1.520	1.421–1.626	<0.001	1.108	0.970–1.266	0.131
LN metastasis	Absent/present	1.748	1.552–1.969	<0.001	14.877	7.332–30.187	<0.001	1.748	1.552–1.969	<0.001	14.624	7.029–30.426	<0.001
N stage*	N0/N1/N2	4.263	3.614–5.028	<0.001	0.643	0.413–1.001	0.051	4.263	3.614–5.028	<0.001	0.648	0.411–1.021	0.062
Lung metastasis	Absent/present							5.251	4.253–6.482	<0.001	3.135	2.182–4.505	<0.001
Bone metastasis	Absent/present							6.049	4.130–8.860	<0.001	3.054	1.609–5.794	0.001
Brain metastasis	Absent/present							5.283	1.545–18.071	0.008	1.214	0.061–23.986	0.898

Notes: *Based on the 8thTNM stage classification. Model 1: predictive model consisted of clinical and pathological factors; model 2: predictive model consisted of model 1 and additional distant metastatic sites.

Abbreviations: OR, odds ratio; CI, confidence interval; LN, lymph node.

Figure 1 Nomograms predicting risk of the liver metastasis in patients with pancreatic ductal adenocarcinoma (A, model 1; B, model 2).

Notes: Model 1: predictive model consisted of clinical and pathological factors; model 2: predictive model consisted of model 1 and additional distant metastatic sites.

Abbreviation: LN, lymph node.

Figure 2 The calibration plots and ROC curves of model 1 in the training cohort (A and C, respectively) and the validation cohort (B and D, respectively).

Notes: Model 1: predictive model consisted of clinical and pathological factors.

Abbreviation: ROC, receiver operating characteristic.

Figure 3 The calibration plots and ROC curves of model 2 in the training cohort (A and C, respectively) and validation cohort (B and D, respectively).

Notes: Model 2: predictive model consisted of model 1 and additional distant metastatic sites.

Abbreviation: ROC, receiver operating characteristic.

Table 3 Comparison of the C-index values and likelihood ratio tests between two models

Nomogram	C-index	P-value	Log likelihood	Chi-square value	P-value
Training cohort
Model 1	0.764 (0.748–0.780)	0.068	−2532.900	166.980	<0.001
Model 2	0.784 (0.768–0.800)		−2449.400
Validation cohort
Model 1	0.769 (0.737–0.801)	0.111	−672.68	54.893	<0.001
Model 2	0.790 (0.760–0.820)		−645.24

Notes: Model 1: predictive model consisted of clinical and pathological factors; model 2: predictive model consisted of model 1 and additional distant metastatic sites.

Abbreviation: C-index, concordance index.

Figure 4 Decision curve analysis for models 1 and 2. The y-axis represents net benefit. The x-axis shows the threshold probability. “All” refers to the assumption that all patients have liver metastasis and “none” to the assumption that no patient had liver metastasis.

Notes: Model 1: predictive model consisted of clinical and pathological factors; model 2: predictive model consisted of model 1 and additional distant metastatic sites.