Table 3.

Association of urinary PGE-M levels and risk of gastric cancer stratified by median time interval between urine collection and cancer diagnosis

	PGE-M (quartiles, ng/mg creatinine)
Time after Urine Collection	1 (< 2.83)	2 (2.83–5.36)	3 (5.37–9.16)	4 (≥ 9.17)	p for trend*
≤ 46.3 mos (72 pairs)
No. of cases	15	13	19	25
No. of controls	19	16	22	15
OR (95% CI)†	1.00	1.10 (0.38–3.22)	1.26 (0.43–3.66)	2.75 (0.84–8.94)	0.09
> 46.3 mos (72 pairs)
No. of cases	14	15	20	23
No. of controls	17	21	15	19
OR (95% CI)†	1.00	0.99 (0.34–2.90)	1.96 (0.62–6.17)	1.48 (0.52–4.20)	0.29

^*P value for linear trend tested by including a variable coded 0, 1, 2, and 3

^†Adjusted for body mass index, education, fruit and vegetable intake, smoking status, NSAID use, and family history of gastric cancer