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.

Table 2 Oncologic outcomes of patients in two groups n (%)

	Ypstage I	Pstage I	P value
Local recurrence rate	2 (4.4)	1 (2.6)	1.0001
Distant metastasis rate	6 (13.3)	3 (7.7)	0.4941
5-yr DFS rate	38 (84.4)	36 (92.3)	0.327
5-yr OS rate	40 (88.9)	36 (92.3)	0.692

Fisher’s exact test. DFS: Disease free survival; OS: Overall survival.

Table 3 Correlation between clinical stage and disease progression in ypstage I group

Clinical stage	Disease progression (n)		OR (95% CI)	P value
	Yes	No
cT3-4N0	3	12	0.31-8.43	0.6701
cTanyN+	4	26

Fisher’s exact test. OR: Odds ratio.

Table 4 Correlation between adjuvant chemotherapy and disease progression in ypstage I group

Adjuvant chemotherapy	Disease progression (n)		OR (95% CI)	P value
	Yes	No
Yes	2	17	0.09-2.87	0.6811
No	5	21

Fisher’s exact test. OR: Odds ratio

Table 5 Multivariate analysis of disease-free survival rate by COX model (forward method)

Variable	Hazard ratio	95% CI	P value
Pretreatment serum CEA	5.535	1.574-19.468	0.008
Distance from anal verge	0.715	0.453-1.130	0.064
Gender	0.483	0.174-1.337	0.154
Age	1.057	0.999-1.119	0.054
Neoadjuvant radiotherapy	0.490	0.176-1.362	0.244
Histological differentiation	1.161	0.452-2.980	0.929
Pathologic T stage	0.827	0.232-0.953	0.271
Lymphovascular invasion	1.643	0.164-16.480	0.829
NELN	0.946	0.880-1.017	0.244
Adjuvant chemotherapy	1.381	0.512-3.725	0.670

NELN: Number of examined lymph nodes; CEA: Carcinoembryonic antigen.