Table 2. Colorectal Cancer Incidence Rates per 10 000 Person-Years by Adenoma Category at Index Colonoscopy Among Participants Aged 55 to 74 Years Enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Randomized Clinical Trial.
| Advanced Adenoma | Nonadvanced Adenoma | No Adenoma All (n = 7985) |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All (n = 2882) | ≥1 cm (n = 2178) | <1 cm (n = 704)a | All (n = 5068) | ≥3 (n = 572) | 1-2 (n = 4496) | |||||||||
| No. of Cases | Rate | No. of Cases | Rate | No. of Cases | Rate | No. of Cases | Rate | No. of Cases | Rate | No. of Cases | Rate | No. of Cases | Rate | |
| No. of person-years at 15 y | 34 993 | 26 494 | 8499 | 60 650 | 6838 | 53 812 | 94 248 | |||||||
| Colorectal Cancer Incidence | ||||||||||||||
| Within 3 y | 16 | 18.9 | 14 | 21.7 | 2 | 9.6 | 2 | 1.3 | 0 | 0 | 2 | 1.5 | 8 | 3.4 |
| Within 5 y | 27 | 19.2 | 22 | 20.7 | 5 | 14.6 | 11 | 4.4 | 1 | 3.6 | 10 | 4.6 | 22 | 5.6 |
| >5 to 10 y | 29 | 23.1 | 20 | 21.1 | 9 | 29.3 | 26 | 11.8 | 3 | 12.1 | 23 | 11.7 | 26 | 7.5 |
| Within 10 y | 56 | 21.1 | 42 | 20.9 | 14 | 21.5 | 37 | 7.9 | 4 | 7.6 | 33 | 7.9 | 48 | 6.5 |
| >10 to 15 y | 14 | 16.7 | 9 | 14.1 | 5 | 25.0 | 18 | 13.1 | 3 | 19.4 | 15 | 12.3 | 23 | 11.4 |
| Within 15 y (cumulative) | 70 | 20.0 | 51 | 19.2 | 19 | 22.4 | 55 | 9.1 | 7 | 10.2 | 48 | 8.9 | 71 | 7.5 |
| RD vs No Adenoma |
RD (95% CI) |
P Value |
RD (95% CI) |
P Value |
RD (95% CI) |
P Value |
RD (95% CI) |
P Value |
RD (95% CI) |
P Value |
RD (95% CI) |
P Value |
RD (95% CI) |
|
| At 10-y | 14.6 (8.8 to 20.4) |
<.001 | 14.4 (7.8 to 21.0) |
<.001 | 15.0 (3.6 to 26.4) |
.01 | 1.4 (−1.7 to 4.5) |
.38 | 1.1 (−6.6 to 8.8) |
.78 | 1.4 (−1.9 to 4.7) |
.40 | 0 [Reference] | |
| At 15-y | 12.5 (7.5 to 17.5) |
<.001 | 11.7 (6.1 to 17.3) |
<.001 | 14.9 (4.7 to 25.1) |
.004 | 1.6 (−1.4 to 4.6) |
.29 | 2.7 (−5.1 to 10.5) |
.49 | 1.4 (−1.5 to 4.5) |
.37 | 0 [Reference] | |
| RR vs No Adenoma |
RR (95% CI) |
P Value |
RR (95% CI) |
P Value |
RR (95% CI) |
P Value |
RR (95% CI) |
P Value |
RR (95% CI) |
P Value |
RR (95% CI) |
P Value |
RR (95% CI) |
|
| At 10-y | 3.3 (2.2 to 4.8) |
<.001 | 3.2 (2.1 to 4.9) |
<.001 | 3.3 (1.8 to 6.0) |
<.001 | 1.2 (0.8 to 1.9) |
.37 | 1.2 (0.4 to 3.2) |
.77 | 1.2 (0.8 to 1.9) |
.37 | 1 [Reference] | |
| At 15-y | ||||||||||||||
| Unadjusted | 2.7 (1.9 to 3.7) |
<.001 | 2.6 (1.8 to 3.7) |
<.001 | 3.0 (1.8 to 4.9) |
<.001 | 1.2 (0.8 to 1.7) |
.30 | 1.4 (0.6 to 3.0) |
.44 | 1.2 (0.8 to 1.7) |
.37 | 1 [Reference] | |
| ARR (model)b | 2.6 (1.9 to 3.7) |
<.001 | 2.5 (1.8 to 3.7) |
<.001 | 2.8 (1.7 to 4.7) |
<.001 | 1.2 (0.8 to 1.7) |
.32 | 1.2 (0.5 to 2.7) |
.71 | 1.2 (0.8 to 1.7) |
.33 | 1 [Reference] | |
| ARR (model excluding participants with inadequate colonoscopy [N = 1213])b,c | 3.0 (2.1 to 4.3) |
<.001 | 2.9 (2.0 to 4.3) |
<.001 | 3.2 (1.8 to 5.5) |
<.001 | 1.3 (0.9 to 1.9) |
.20 | 1.3 (0.9 to 1.9) |
.73 | 1.2 (0.5 to 2.9) |
.19 | 1 [Reference] | |
Abbreviations: ARR, adjusted rate ratio; RD, rate difference; RR, rate ratio.
a
Advanced adenomas <1 cm were defined as villous or tubulovillous or high-grade dysplasia on histology.
b
Adjusted risk-ratio from Poisson regression (controlling for age, sex, aspirin or ibuprofen use, and time of initial colonoscopy [baseline vs postbaseline] for 15-y data).
c
Excludes participants with inadequate colonoscopy (n = 1213). If the colonoscopy preparation was designated as inadequate or if the cecum was not visualized, the examination was classified as inadequate. If the preparation quality was not reported but the cecum was visualized, the colonoscopy examination was considered adequate.