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

Table 1 Patient characteristics

Variable	TLN ≥ 12 (group A, n = 177)	TLN < 12 (group B, n = 54)	P value
Sex (n, %)			0.591
Male	121 (68.4)	39 (72.2)
Female	56 (31.6)	15 (27.8)
Age (yr)	60 (51-65)	59.5 (52.75-66.5)	0.544
ASA score (n, %)			0.488
1	5 (2.8)	2 (3.7)
2	139 (78.6)	39 (72.2)
3	33 (18.6)	13 (24.1)
BMI (kg/m2)	23.8 (21.9-26.4)	23.4 (21.5-25.2)	0.423
cT, n (%)			0.975
2	2 (1.1)	0 (0)
3	137 (77.4)	43 (79.6)
4	38 (21.5)	11 (20.4)
cN, n (%)			0.109
0	44 (24.9)	18 (33.3)
1	91 (51.4)	28 (51.9)
2	42 (23.7)	8 (14.8)
Preoperative CEA (μg/L)	2.99 (1.55-5.57)	3 (1.68-5.57)	0.729
ypT, n (%)			0.140
0	26 (14.7)	14 (25.9)
1	4 (2.3)	1 (1.9)
2	37 (20.9)	11 (20.4)
3	97 (54.8)	24 (44.4)
4	13 (7.3)	4 (7.4)
ypN, n (%)			0.026
0	90 (50.8)	38 (70.4)
1	64 (36.2)	10 (18.5)
2	23 (13)	6 (11.1)
TRG, n (%)			0.312
0	14 (7.9)	4 (7.4)
1	26 (14.7)	7 (13)
2	78 (44.1)	22 (40.7)
3	33 (18.6)	7 (13)
4	26 (14.7)	14 (25.9)
No downstaging, n (%)	98 (55.4)	20 (37)	0.019
Downstaging, n (%)	56 (31.6)	21 (38.9)	0.324
pCR, n (%)	26 (14.7)	14 (25.9)	0.057
Positive lymph nodes, n (%)	0 (0-1)	0 (0-0)	0.003
LNR	0 (0-0.68)	0 (0-0)	0.012
Radiotherapy dose, n (%)			0.557
45-50.4 Gy/28 F	125 (70.6)	39 (72.2)
< 45 Gy/25 F	34 (19.2)	5 (9.3)
25 Gy/5 F	18 (10.2)	10 (18.5)
Preoperative concurrent chemotherapy regimen, n (%)			0.376
Capecitabine+ oxaliplatin	54 (30.5)	17 (31.5)
Capecitabine, oral	108 (61)	37 (68.5)
Fluorouracil union	15 (8.5)	0 (0)
Tumor location, DAV (cm)	5 (3-7)	5 (3-7)	0.605
Interval, w (%)	8 (6.5-11)	10 (8-16)	0.001
Surgical procedure			0.018
Miles (n, %)	74 (41.8)	26 (48.2)
Dixon (n, %)	93 (52.5)	20 (37)
Hartmann (n, %)	10 (5.6)	8 (14.8)
LLND (n, %)	20 (11.3)	1 (1.9)	0.035
Multivisceral resection (n, %)	10 (5.6)	2 (3.7)	0.574
PNI (n, %)			0.819
Yes	42 (23.7)	12 (22.2)
No	135 (76.3)	42 (77.8)
Intravascular tumor embolus (n, %)			0.463
Yes	23 (13)	5 (9.3)
No	154 (87)	49 (90.7)
Degree of differentiation, n (%)			0.367
Low and low-middle grades	18 (10.2)	9 (16.7)
Middle, high-middle, and high grades	132 (74.6)	43 (79.6)
Signet-ring and mucinous adenocarcinoma	4 (2.3)	2 (3.7)

TLN: Total number of retrieved lymph nodes; BMI: Body mass index; CEA: Carcinoembryonic antigen; ASA: American Society of Anesthesiologists; TRG: Tumor regression grade; LNR: Lymph node ratio; DAV: Distance from anal verge; LLND: Lateral lymph node dissection; PNI: Perineural invasion; pCR: Pathological complete response; F: Fractions.