. Author manuscript; available in PMC: 2019 Jul 1.

Published in final edited form as: Cancer Epidemiol Biomarkers Prev. 2018 May 16;27(7):728–736. doi: 10.1158/1055-9965.EPI-17-0573

TABLE 3.

Association of biomarkers and study treatment outcome with pre-treatment and on study aspirin use

Aspirin users
Biomarker result, patients receiving placebo	No. at risk	3-year cumulative adenoma incidence (SE)	Risk Ratio (95% confidence interval)	p-value
15-PGDH present	16	32.5% (12.1)	2.10 (0.95, 4.65)	0.05
15-PGDH absent	126	63.0% (4.5)	2.10 (0.95, 4.65)	0.05
Cox-2 high	12	83.3% (13.6)	0.62 (0.41,0.96)	0.09
Cox-2 low	130	57.6% (4.5)	0.62 (0.41,0.96)	0.09

No Aspirin use
Biomarker result, patients receiving placebo	No. at risk	3-year cumulative adenoma incidence (SE)	Risk Ratio (95% confidence interval)	p-value
15-PGDH present	36	60.0% (8.5)	0.98(0.70, 1.38)	0.99
15-PGDH absent	262	63.4% (3.1)	0.98(0.70, 1.38)	0.99
Cox-2 high	16	63.5% (12.3)	0.92(0.58,1.46)	0.82
Cox-2 low	282	63.1% (3.0)	0.92(0.58,1.46)	0.82

Predictive biomarker assessment: All patients
Risk Ratio for on-study adenoma detection (95% confidence interval)
	All patients	ASA users	No ASA use
15-PGDH present	0.73 (0.47,1.12) N=139	1.16 (0.45,2.96) N=45	0.60 (0.36,0.99) N=94
15-PGDH absent	0.60 (0.52,0.69) N=1156	0.60 (0.47,0.77) N=364	0.60 (0.51,0.71) N=792
Cox-2 high	0.37 (0.22,0.61) N=106	0.16 (0.05,0.50) N=34	0.50 (0.27,0.93) N=72
Cox-2 low	0.64 (0.56,0.73) N=1189	0.71 (0.55,0.91) N=375	0.61 (0.52,0.72) N=814