Risk factors, prognostic predictors, and nomograms for pancreatic cancer patients with initially diagnosed synchronous liver metastasis

Table 3 Multivariate Cox analysis of the training cohort based on the results of least absolute shrinkage and selection operator regression, n (%)

Variable	Levels	All	Multivariate analysis (HR, 95%CI)
Age at diagnosis (yr)	≤ 70	4812 (62.5)
	> 70	2886 (37.5)	1.29 (1.23-1.36, P < 0.001)
Histology	Adenocarcinoma	5867 (76.2)
	Neuroendocrine carcinoma	411 (5.3)	0.31 (0.28-0.35, P < 0.001)
	Other	1420 (18.4)	0.79 (0.75-0.85, P < 0.001)
Pathological grade	Well/moderate	799 (10.4)
	Poor/anaplastic	919 (11.9)	1.72 (1.55-1.91, P < 0.001)
	Unspecific	5980 (77.7)	1.48 (1.36-1.61, P < 0.001)
Surg prim	No	7429 (96.5)
	Yes	269 (3.5)	0.37 (0.31-0.43, P < 0.001)
Surg dis	No	7450 (96.8)
	Yes	248 (3.2)	0.80 (0.69-0.93, P = 0.004)
Chemotherapy	No	2934 (38.1)
	Yes	4764 (61.9)	0.43 (0.41-0.45, P < 0.001)
Lung metastasis	No	6510 (84.6)
	Yes	1188 (15.4)	1.35 (1.27-1.44, P < 0.001)

HR: Hazard ratio; CI: Confidence interval; Surg prim: Surgical treatments of the primary site; Surg dis: Surgical treatments of the distant site.