Table 4.
Treatment efficacy in preventing metachronous colorectal adenoma, stratified by level of biomarker response (percent change in biomarker level between baseline and 36 months)
| Biomarker decreased by ≥ 30% (Responders) |
Biomarker increased, or decreased by < 30% (Non-responders) |
P* | ||
|---|---|---|---|---|
| PGE2 | ||||
| Placebo, events/total (%) | 4/17 (23.5) | 15/32 (46.9) | ||
| DFMO/sulindac, events/total (%) | 1/11 (9.09) | 8/35 (22.9) | ||
| RR (95% CI) | 0.39 (0.05 – 3.02) | 0.49 (0.24 – 0.99) | 0.980 | |
| Spd:Spm | ||||
| Placebo, events/total (%) | 17/41 (41.5) | 33/77 (42.9) | ||
| DFMO/sulindac, events/total (%) | 8/83 (9.64) | 8/38 (21.1) | ||
| RR (95% CI) | 0.23 (0.11 – 0.49) | 0.49 (0.25 – 0.96) | 0.202 | |
| Putrescine | ||||
| Placebo, events/total (%) | 22/46 (47.8) | 28/72 (38.9) | ||
| DFMO/sulindac, events/total (%) | 9/61 (14.8) | 7/60 (11.7) | ||
| RR (95% CI) | 0.31 (0.16 – 0.61) | 0.30 (0.14 – 0.64) | 0.886 | |
Abbreviations: DFMO, difluoromethylornithine; PGE2, prostaglandin E2; RR, relative risk; CI, confidence interval; Spd:Spm, spermidine-to-spermine ratio
*
P value for the likelihood ratio test of interaction between treatment group and biomarker response