Para-aortic lymph node involvement should not be a contraindication to resection of pancreatic ductal adenocarcinoma

Table 1 Patient demographics, operative and pathological characteristics and outcomes

Factors	Total (n = 81)	PALN+ (n = 17)	PALN- (n = 64)	P value
Demographics
Age (median and range in years)	69 (43-84)	68.8 (61-72.3)	69 (61-75)	0.404
Gender, male (%)	38 (47)	12 (71)	33 (52)	0.171
BMI (kg/m2)	25.1 (22.0-27.8)	26.2 (22.2-27.8)	24.9 (21.9-27.7)	0.413
Non-smoker (%)	13 (73)	14 (82)	46 (72)	0.462
Preoperative CA19-9 levels (KU/L)	286 (2-36000)	410 (14-2784)	252 (2-36000)	0.594
Charlson comorbidity index	4 (3-5)	4 (3-5)	4.5 (3-5)	0.079
Preoperative radiological stage n (%)
Resectable	41 (51)	8 (47)	33 (52)	0.601
Borderline resectable	31 (38)	8(47)	23 (36)
Locally advanced	9 (11)	1 (6)	8 (12)
Operation, n (%)
Distal pancreatectomy	1 (1)	0	1 (1)	0.681
Total pancreatectomy	14 (17)	2 (12)	12 (19)
Pancreaticoduodenectomy	66 (82)	15 (88)	51 (80)
Vein resection	33 (41)	7 (41)	26 (41)	0.310
Arterial resection	3 (4)	1 (6)	2 (3)	0.842
Pathological staging, n (%)				1.000
pT1	13 (16)	3 (18)	10 (16)	0.951
pT2	46 (57)	9 (53)	37 (58)
pT3	21 (26)	5 (29)	16 (25)
pT4	1 (1)	0	1 (1)
pN0	14 (79)	0	14 (22)	0.005
pN1	24 (30)	3 (18)	21 (33)
pN2	43 (53)	14 (82)	29 (45)
Resection margin, n (%)
Negative	39 (48)	6 (35)	33 (52)	0.282
Positive	42 (52)	11 (65)	31 (48)
Perineural invasion	66 (83)	15 (88)	51 (80)	0.722
Perivascular invasion	59 (73)	13 (77)	46 (72)	1.000
Chemotherapy, n (%)	55 (74)	12 (71)	43 (67)	0.746
Neoadjuvant therapy	13 (16)	2 (12)	11 (17)	0.726
Adjuvant chemotherapy	49 (66)	12 (71)	37 (58)	0.553
Post-operative complications, n (%)
Clavien Dindo category ≥ 3	10 (12)	2 (11.8)	8 (12.5)	0.549
Chyle leak	1 (1)	0	1 (1.56)	0.835
Perioperative haemorrhage	2 (2)	0	2 (3.13)	0.712
Comprehensive complication index	0 (0-20.9)	0 (0-20.9)	0 (0-20.9)	0.083
Hospital length of stay (median and range in days)	9 (1-76)	8 (5-30)	10 (1-76)	0.138

BMI: Body mass index; PALN: Para-aortic lymph nodes.

Table 2 Risk analysis for overall survival

	Univariable		Multivariable
	P value	HR (CI)	P value	HR (CI)
Age	0.668	0.994 (0.966-1.022)
Sex	0.359	0.756 (0.416-1.374)
Preoperative CA19-9	0.626	1.000 (1.000-1.000)
Pre-operative stage	0.949	0.986 (0.641-1.517)
Resection type	0.517	1.141 (0.765-1.702)
Venous resection	0.659	1.146 (0.625-2.104)
Arterial resection	0.327	2.045 (0.489-8.559)
pT	0.001	2.148 (1.368-3.371)	0.008
pT1			0.842	1.114 (0.385-3.226)
pT2			0.115	2.459 (0.803-7.536)
pT3			0.008	31.275 (2.491-392.605)
pN	0.002	2.195 (1.337-3.604)	0.004
pN1			0.329	2.332 (0.427-12.740)
pN2			0.016	7.564 (1.459-39.224)
PALN positivity	0.041	1.970 (1.028-3.776)
Margin status	0.007	2.331 (1.261-4.308)	0.049	1.986 (1.003-3.932)
Perineural invasion	0.212	1.691 (0.741-3.861)
Perivascular invasion	0.464	1.278 (0.663-2.461)
Chemotherapy	0.033	0.487 (0.251-0.944)	0.002	0.283 (0.129-0.622)

All parameters with P < 0.200 on univariable entered into multivariable model. HR: Hazard ratios; CI: Confidence intervals; PALN: Para-aortic lymph nodes.

Table 3 Risk analysis for disease-free survival

	Univariable		Multivariable
	P value	HR (CI)	P value	HR (CI)
Age	0.129	0.979 (0.952-1.006)	0.023	0.964 (0.933-0.995)
Sex	0.881	0.955 (0.526-1.736)
Preoperative CA19-9	0.773	1.000 (1.000-1.000)
Preoperative stage	0.943	1.016 (0.656-1.573)
Resection type	0.215	1.272 (0.869-1.862)
Venous resection	0.739	0.899 (0.481-1.681)
Arterial resection	0.567	0.048 (0.000-1578.950)
pT	0.002	2.102 (1.308-3.378)	0.004
pT1			0.265	1.726 (0.661-4.509)
pT2			0.015	3.689 (1.287-10.576)
pT3			0.002	49.543 (4.018-610.815)
pN	0.121	1.387 (0.917-2.097)
PALN positivity	0.101	1.748 (0.896-3.410)	0.045	2.287 (1.018-5.136)
Margin status	0.032	1.927 (1.057-3.514)	0.007	2.48 (1.275-4.822)
Perineural invasion	0.103	2.084 (0.862-5.036)	0.041	2.938 (1.045-8.255)
Perivascular invasion	0.152	1.657 (0.830-3.308)
Chemotherapy	0.047	0.509 (0.261-0.992)	0.001	0.242 (0.105-0.559)

All parameters with P < 0.200 on univariable entered into multivariable model. HR: Hazard ratios; CI: Confidence intervals; PALN: Para-aortic lymph nodes.