Oncologic outcomes of primary and post-irradiated early stage rectal cancer: A retrospective cohort study

Table 1 Characteristics of patients included in this study

Characteristic	Group		P value
	Ypstage I (n = 45)	Pstage I (n = 39)
Gender
Male	28	21	0.437
Female	17	18
Age (yr)
< 60	19	10	0.111
> 60	26	29
Median	62	67
Distance from anal verge (cm)
≤ 5	20	9	0.040
> 5	25	30
Pretreatment serum CEA (ng/mL)
≤5	29	32	0.016
> 5	13	3
unknown	3	4
Surgery
APR	14	6	0.091
LAR	31	33
Clinical and pathologic stage
cT1-2N0	0	28	< 0.001
cT3-4N0	15	6
cTanyN+	30	5
pT1N0	5	14	0.007
pT2N0	40	25
Histological differentiation
High	3	15	< 0.001
Moderate	34	23
Poor	8	1
Lymphovascular invasion
Positive	0	1	0.464
Negative	45	38
NELN
< 12	27	23	0.924
≥ 12	18	16

APR: Abdominoperineal resection; LAR: Low anterior resection; NELN: Number of examined lymph nodes; CEA: Carcinoembryonic antigen.