Impact factors of lymph node retrieval on survival in locally advanced rectal cancer with neoadjuvant therapy

Table 4 Results of Kaplan-Meier analysis

Variable	No. of cases	DFS P value	OS P value
Sex (n, %)		0.708	0.655
Male	160 (69.3)
Female	71 (30.7)
Age (yr)		0.86	0.968
< 60	111 (48.1)
≥ 60	120 (51.9)
ASA score (n, %)		0.912	0.951
1	7 (3)
2	178 (77)
3	46 (19.9)
BMI (kg/m2)		0.519	0.512
< 25	149 (64.5)
≥ 25	82 (35.5)
cT, n (%)		0.606	0.476
2	2 (0.9)
3	180 (77.9)
4	49 (21.2)
cN, n (%)		0.003	0.063
0	79 (34.2)
1	112 (48.5)
2	40 (17.3)
ypT, n (%)		< 0.001	< 0.001
0	36 (15.6)
1	6 (2.6)
2	50 (21.6)
3	122 (52.8)
4	17 (7.4)
ypN, n (%)		< 0.001	0.097
0	128 (55.4)
1	74 (32)
2	29 (12.6)
TLN, n (%)		0.006	0.737
< 12	54 (23.4)
≥ 12	177 (76.6)
Positive lymph nodes, n (%)		< 0.001	0.063
< 2	182 (78.8)
≥ 2	49 (21.2)
LNR		< 0.001	0.058
≤ 0.03
> 0.03
Preoperative concurrent chemotherapy regimen, n (%)		0.148	0.561
Capecitabine+ oxaliplatin	58 (25.1)
Capecitabine, oral	140 (60.6)
Oxaliplatin combination	22 (9.5)
Postoperative chemotherapy		0.933	0.869
Yes	153 (66.2)
No	78 (33.8)
Interval, w (%)		0.044	0.567
≤ 8 wk	139 (60.2)
> 8 wk	92 (39.8)
Surgical procedure		0.168	0.662
Miles (n, %)	100 (43.3)
Dixon (n, %)	113 (48.9)
Hartmann (n, %)	18 (7.8)
LLND (n, %)	21 (9.1)	0.868	0.994
Multivisceral resection (n, %)	12 (5.2)	0.025	0.948
Preoperative CEA (μg/L)		0.344	0.663
< 5	166 (71.9)
≥ 5	65 (28.1)
PNI (n, %)		< 0.001	< 0.001
Yes	54 (23.4)
No	177 (76.6)
Intravascular tumor embolus (n, %)		< 0.001	0.004
Yes	28 (12.1)
No	203 (87.9)
Degree of differentiation, n (%)		0.028	0.152
Low and low-middle grades	32 (13.9)
Middle, high-middle, and high grades	193 (83.5)
Signet-ring and mucinous adenocarcinoma	6 (2.6)

DFS: Disease-free survival; OS: Overall survival; BMI: Body mass index; ASA: American Society of Anesthesiologists; LLND: Lateral lymph node dissection; TLN: Total number of retrieved lymph nodes; CEA: Carcinoembryonic antigen; PNI: Perineural invasion.