Table 2.

Association of adenoma occurrence during study treatment with urinary PGE-M, PGI-M, and dTxB2 levels, the AFPPS

Biomarker/quartile rangeAny adenomaLow-risk adenomaaHigh-risk findingsaAdvanced adenomaa
Cases/total NRRb (95% CI)Cases/total NRRb (95% CI)Cases/total NRRb (95% CI)Cases/total NRRb (95% CI)
PGE-M, ng/mg creatininec
 <4.5771/2071.00 (ref)36/1721.00 (ref)35/1711.0021/2051.00 (ref)
 4.57–7.3777/2071.00 (0.78–1.29)39/1691.07 (0.72–1.61)38/1680.94 (0.63–1.41)22/2040.93 (0.51–1.71)
 7.37–11.3886/2101.00 (0.78–1.28)45/1691.08 (0.72–1.60)41/1650.91 (0.61–1.35)16/2070.59 (0.31–1.11)
 ≥11.3993/2111.07 (0.83–1.37)48/1661.19 (0.80–1.77)45/1630.92 (0.61–1.38)16/2050.56 (0.29–1.08)
Ptrend0.920.530.210.12
PGI-M, ng/mg creatininec
 <0.04970/1961.00 (ref)33/1591.00 (ref)37/1631.00 (ref)18/1941.00 (ref)
 0.049–0.08282/1941.14 (0.90–1.45)41/1531.30 (0.88–1.93)41/1531.10 (0.75–1.60)20/1901.01 (0.55–1.87)
 0.082–0.12476/1941.05 (0.82–1.36)38/1561.21 (0.81–1.82)38/1560.97 (0.65–1.47)19/1920.93 (0.49–1.79)
 ≥0.12580/1961.04 (0.81–1.35)47/1631.40 (0.94–2.09)33/1490.77 (0.51–1.16)13/1920.56 (0.28–1.15)
Ptrend0.920.220.480.16
dTxB2, ng/mg creatininec
 <0.10768/1991.00 (ref)31/1621.00 (ref)37/1681.00 (ref)18/1961.00 (ref)
 0.107–0.19496/2091.33 (1.04–1.69)56/1691.79 (1.22–2.62)40/1531.12 (0.75–1.67)22/2071.04 (0.55–1.93)
 0.195–0.34679/2060.98 (0.74–1.30)42/1691.27 (0.83–1.95)37/1640.78 (0.50–1.21)19/2000.60 (0.29–1.24)
 ≥0.34777/2040.94 (0.69–1.28)34/1611.15 (0.70–1.88)43/1700.72 (0.45–1.15)16/1990.46 (0.22–1.00)
Ptrend0.930.860.890.44
  • aLow-risk adenoma defined as solitary adenomatous polyp < 1 cm in greatest diameter and tubular or unknown histology (high-risk adenoma excluded from the analysis). High-risk adenoma defined as adenomatous polyp ≥1 cm in greatest diameter and/or tubulovillous, villous or high-grade dysplasia, histology or multiple (≥2) adenomatous polyps of any size or histology (low-risk adenoma excluded from the analysis). Advanced adenoma defined as adenomatous polyp with an estimated diameter of ≥1 cm, or at least 25% villous component, any high-grade dysplasia, or invasive cancer.

  • bAdjusted for age (continuous), sex, center (categorical), number of previous adenomas (continuous), follow-up time (continuous) and aspirin treatment group (placebo, 81 mg, 325 mg).

  • cP values for interaction for aspirin treatment group were: for any adenoma, P PGE-M = 0.14, P PGI-M = 0.40, and P dTxB2 = 0.50; for low-risk adenoma, P PGE-M = 0.13, P PGI-M = 0.22, and P dTxB2 = 0.40; for high-risk adenoma, P PGE-M = 0.53, P PGI-M = 0.45, and P dTxB2 = 0.63; and for advanced adenoma, P PGE-M = 0.62, P PGI-M = 0.33, and P dTxB2 = 0.32.