Risk factors for adverse outcome in low rectal cancer

Table 2 Univariate analysis of 331 patients with low rectal cancer

Characteristic	No. of patients	5-year OS		5-year DFS
		%	P value	%	P value
Gender			0.987		0.768
Male	211	61.2		59.2
Female	120	59.6		58.9
Age (yr)			0.707		0.987
< 60	182	58.8		56.4
≥ 60	149	62.7		62.2
Tumor size (cm)			0.011		0.003
< 4	103	74.8		74.0
≥ 4	228	54.1		52.3
Distance of tumor from the anal verge (cm)			0.189		0.197
< 3.5	117	60.1		58.1
≥ 3.5	214	60.9		59.6
Type of surgery			0.018		0.013
APR	172	54.6		52.9
SPS	159	66.8		65.6
Resection margins			< 0.001		< 0.001
Negative	298	63.8		62.1
Positive	33	32.5		32.5
Histopathologic grade			0.006		0.002
Well	61	66.5		66.5
Moderate	210	63.6		61.9
Poor	60	43.6		41.6
pT stage			< 0.001		< 0.001
1-2	125	74.0		71.9
3-4	206	52.4		51.2
pTNM stage			< 0.001		< 0.001
I-II	174	75.4		73.3
III-IV	157	44.0		43.1
Mucin production			0.212		0.121
No	307	61.7		60.3
Yes	24	44.8		42.6
Anastomotic leakage1			0.310		0.386
No	153	67.6		66.3
Yes	6	50.0		50.0
Adjuvant chemotherapy			0.950		0.573
No	268	60.2		58.4
Yes	63	62.2		62.2

OS: Overall survival; DFS: Disease-free survival; APR: Abdominoperineal resection; SPS: Sphincter-preserving surgery.

¹Analysis of 159 patients who underwent sphincter-preserving surgery.