Longitudinal evolution of low anterior resection syndrome in ultra-low rectal cancer: A trend analysis of a propensity-matched cohort

Table 1 Comparison of baseline characteristics in the pre-matched cohort (n = 403), n (%)

Characteristic	n	Ultra-low group (≤ 3 cm; n = 114)	Non-ultra-low group (> 3 cm; n = 289)	Test statistic	P value
Age (year)	403	57.24 ± 11.74	60.73 ± 10.87	t = -2.839	0.005
Gender
Female	168	42 (36.8)	126 (43.6)	χ2 = 1.535	0.215
Male	235	72 (63.2)	163 (56.4)
BMI (kg/m2)		23.67 ± 3.21	23.33 ± 3.02	t = 1.008	0.314
Blood type
A	130	38 (33.3)	92 (31.8)	χ2 = 0.326	0.955
AB	36	10 (8.8)	26 (9.0)
B	91	27 (23.7)	64 (22.1)
O	146	39 (34.2)	107 (37.0)
Diabetes
No	336	95 (83.3)	241 (83.4)	χ2 = 0.000	0.989
Yes	67	19 (16.7)	48 (16.6)
Hypertension
No	281	80 (70.2)	201 (69.6)	χ2 = 0.015	0.902
Yes	122	34 (29.8)	88 (30.4)
Tumor pathology
Adenocarcinoma	364	101 (88.6)	263 (91.0)	χ2 = 0.832	0.842
Mucinous adenocarcinoma	34	11 (9.6)	23 (8.0)
Neuroendocrine carcinoma	2	1 (0.9)	1 (0.3)
Signet ring cell carcinoma	3	1 (0.9)	2 (0.7)
TNM
0	28	14 (12.3)	14 (4.8)	χ2 = 18.288	0.001
I	89	35 (30.7)	54 (18.7)
II	114	22 (19.3)	92 (31.8)
III	115	26 (22.8)	89 (30.8)
IV	57	17 (14.9)	40 (13.8)
Postoperative complications
None	384	110 (96.5)	274 (94.8)	χ2 = 8.413	0.394
Anastomotic bleeding	9	2 (1.8)	7 (2.4)
Anastomotic leaks including invisible leaks	2	0 (0.0)	2 (0.7)
Stoma obstruction or intestinal obstruction	1	1 (0.9)	0 (0.0)
Incisional infection or incisional hernia	5	1 (0.9)	4 (1.4)
Other: e.g. high blood pressure, cardiac arrhythmia, deep vein thrombosis of the lower limbs	2	0 (0.0)	2 (0.6)
Neoadjuvant radiotherapy
No	287	47 (41.2)	240 (83.0)	χ2 = 69.738	< 0.001
Yes	116	67 (58.8)	49 (17.0)
Neoadjuvant chemotherapy
No	169	26 (22.8)	143 (49.5)	χ2 = 23.888	< 0.001
Yes	234	88 (77.2)	146 (50.5)

BMI: Body mass index.