Table 2. Correlation between DiAcSpm and clinicopathological factors.

	Urinary DASr
Factors	Low	High	P-valuea
Age at initial diagnosis (years)
⩽68	55	25
>68	47	29	0.403
Sex
Male	51	16
Female	51	38	0.017
Smoking history
Never	43	21
Eever/current	59	33	0.735
Serum CEA level
<5.0 ng dl−1	86	38
⩾5.0 ng dl−1	16	16	0.059
Histological type
Adenocarcinoma	82	28
Non-adenocarcinoma	20	26	<0.001
Tumour size
⩽30 mm	84	24
>30 mm	18	30	<0.001
Pathological stage
I	85	29
II or III	17	25	<0.001
Lymphatic invasion
Negative	87	35
Positive	15	19	<0.001
Vascular invasion
Negative	74	24
Positive	28	29	0.001
Pleural invasion
Negative	86	27
Positive	16	27	<0.001

Abbreviations: CEA=carcinoembryonic antigen; DASr=N¹, N¹²-diacetylspermine/cutoff ratio; DiAcSpm=N¹, N¹²-diacetylspermine.

^aFisher's exact test.