Abdominoperineal excision following preoperative radiotherapy for rectal cancer: Unfavorable prognosis even with negative circumferential resection margin

Table 1 Clinical and pathological features of abdominoperineal excision and non- abdominoperineal excision groups n (%)

Variates		Non-APE (n =178)	APE (n = 78)	P value
Gender
	Male	92 (51.7)	53 (67.9)	0.016
	Female	86 (48.3)	25 (32.1)
Age (yr)
	< 65	119 (66.9)	56 (71.8)	0.434
	≥ 65	59 (33.1)	22 (28.2)
Level of tumor
	≤ 5 cm	82 (46.1)	72 (92.3)	0.000
	> 5 cm	96 (53.9)	6 (7.7)
BMI (kg/m2)
	≤ 23.5	97 (54.5)	28 (35.9)	0.006
	> 23.5	81 (45.5)	50 (64.1)
Pre-operative CEA1
	≤ 5 ng/mL	97 (63.0)	41 (66.1)	0.664
	> 5 ng/mL	57 (37.0)	21 (33.9)
Differentiation
	ypCR	12 (6.7)	6 (7.7)	0.651
	G1-2	120 (67.4)	56 (71.8)
	G3-4	46 (25.8)	16 (20.5)
TRG
	Complete regression	12 (6.7)	6 (7.7)	0.402
	Major regression	27 (15.2)	7 (9.0)
	Minor regression	139 (78.1)	65 (83.3)
ypT
	T0	12 (6.7)	6 (7.7)	0.511
	T1	11 (6.2)	5 (6.4)
	T2	56 (31.5)	29 (37.2)
	T3	98 (551)	36 (46.2)
	T4	1 (0.6)	2 (2.6)
ypN
	N0	114 (64.0)	45 (57.7)	0.209
	N1/N1c	37 (20.8)	24 (30.8)
	N2a/b	27 (15.2)	9 (11.5)
ypTNM stage
	ypCR	12 (6.7)	4 (5.1)	0.642
	I	57 (32.0)	26 (33.3)
	II	45 (25.3)	15 (19.2)
	III	64 (36.0)	33 (42.3)

¹Pre-treatment CEA assessment was unavailable in 40 cases. APE: Abdominoperineal excision. CEA: Carcino-embryonic antigen.