Table 2

Cumulative incidence of colorectal cancer and age-sex-standardised incidence ratios in the whole cohort (n=21 318)

n%No of person-yearsNo of CRCsIncidence rate per 100 000 person-years (95% CI)At 10 yearsP value†Standardisation
No of CRCsCumulative incidence (95% CI)*No of expected CRCs‡SIR (95% CI)
After baseline (without surveillance, censored at any first surveillance visit)
Total21 318100116 248214184 (161 to 210)1831.9% (1.7 to 2.3)2420.88 (0.77 to 1.01)
Sex0.50
 Women90224252 43193177 (145 to 217)741.7% (1.3 to 2.2)871.08 (0.87 to 1.32)
 Men12 2965863 816121190 (159 to 227)1092.1% (1.7 to 2.6)1560.78 (0.64 to 0.93)
Age at baseline, years<0.001
 <5542982026 7181245 (26 to 79)90.4% (0.2 to 0.8)130.93 (0.48 to 1.63)
 55–6459562832 35836111 (80 to 154)301.3% (0.9 to 2.0)510.71 (0.50 to 0.98)
 65–7468943235 83194262 (214 to 321)812.6% (2.1 to 3.3)1000.94 (0.76 to 1.15)
 ≥7541702021 34172337 (268 to 425)633.6% (2.7 to 4.7)790.92 (0.72 to 1.15)
No of PMPs<0.001
 112 2315772 860102140 (115 to 170)821.4% (1.1 to 1.8)1440.71 (0.58 to 0.86)
 247142224 97459236 (183 to 305)512.4% (1.8 to 3.2)561.06 (0.81 to 1.37)
 3203510961222229 (151 to 348)202.9% (1.8 to 4.6)221.00 (0.62 to 1.51)
 49514397114353 (209 to 595)145.4% (3.0 to 9.7)91.55 (0.84 to 2.59)
 ≥513877483017352 (219 to 566)163.7% (2.0 to 6.5)111.56 (0.91 to 2.49)
PMP size, mm§0.001
 <1011 5535472 061112155 (129 to 187)951.6% (1.3 to 2.0)1450.77 (0.64 to 0.93)
 10–1960812929 40862211 (164 to 270)522.2% (1.6 to 3.1)640.97 (0.75 to 1.25)
 ≥2036251714 55339268 (196 to 367)353.0% (2.0 to 4.4)331.18 (0.84 to 1.61)
Adenoma histology¶0.002
 Tubular12 7866075 483117155 (129 to 186)1001.6% (1.3 to 2.0)1530.77 (0.63 to 0.92)
 Tubulovillous64803030 69868222 (175 to 281)582.4% (1.8 to 3.2)681.00 (0.78 to 1.27)
 Villous10455450514311 (184 to 525)133.2% (1.7 to 5.9)111.29 (0.70 to 2.16)
 Unknown10075556215270 (163 to 447)123.1% (1.7 to 5.8)101.45 (0.81 to 2.40)
Adenoma dysplasia**<0.001
 Low grade18 59287104 400173166 (143 to 192)1451.7% (1.4 to 2.0)2150.80 (0.69 to 0.93)
 High grade214810837335418 (300 to 582)335.2% (3.6 to 7.7)201.74 (1.21 to 2.42)
 Unknown578334756173 (78 to 384)52.2% (0.8 to 5.8)70.87 (0.32 to 1.89)
Proximal polyps††<0.001
 No11 5665467 07388131 (106 to 162)771.5% (1.2 to 1.9)1330.66 (0.53 to 0.82)
 Yes97524649 174126256 (215 to 305)1062.5% (2.0 to 3.1)1101.15 (0.96 to 1.37)
No of APMPs and PMPs<0.001
 No APMPs, 1 PMP75063549 42366134 (105 to 170)531.3% (1.0 to 1.8)960.69 (0.53 to 0.88)
 No APMPs, 2–4 PMPs33461619 58138194 (141 to 267)342.2% (1.6 to 3.2)430.89 (0.63 to 1.22)
 No APMPs, ≥5 PMPs461219913151 (49 to 467)31.4% (0.4 to 4.5)40.73 (0.15 to 2.14)
 1 APMP, no other PMPs47252223 43736154 (111 to 213)291.6% (1.1 to 2.4)490.74 (0.52 to 1.02)
 ≥1 APMP, ≥2 total PMPs52802521 81571325 (258 to 411)643.6% (2.7 to 4.8)511.39 (1.09 to 1.75)
After first surveillance (with one or more surveillance visits, censored at end of follow-up)
Total11 60410094 567154163 (139 to 191)1221.6% (1.4 to 2.0)2130.72 (0.61 to 0.85)
Sex0.66
 Women48044139 74268171 (135 to 217)561.9% (1.4 to 2.5)671.02 (0.79 to 1.29)
 Men68005954 82586157 (127 to 194)661.5% (1.1 to 1.9)1460.59 (0.47 to 0.73)
Age at baseline, years<0.001
 <5527022324 7462497 (65 to 145)190.9% (0.6 to 1.4)191.25 (0.80 to 1.86)
 55–6437993332 58041126 (93 to 171)301.2% (0.8 to 1.8)690.60 (0.43 to 0.81)
 65–7437803329 35464218 (171 to 279)512.3% (1.7 to 3.1)950.68 (0.52 to 0.86)
 ≥75132311788725317 (214 to 469)223.7% (2.3 to 6.0)300.83 (0.53 to 1.22)
No of PMPs<0.001
 161885351 25761119 (93 to 153)511.3% (1.0 to 1.7)1080.57 (0.43 to 0.73)
 226172320 62641199 (146 to 270)281.6% (1.1 to 2.4)480.85 (0.61 to 1.16)
 3122511987019193 (123 to 302)151.7% (1.0 to 2.9)240.79 (0.48 to 1.23)
 4596548849184 (96 to 354)61.2% (0.5 to 2.7)120.73 (0.33 to 1.38)
 ≥59788793024303 (203 to 452)224.0% (2.5 to 6.3)211.17 (0.75 to 1.74)
PMP size, mm§<0.001
 <1056084844 22154122 (94 to 159)441.3% (0.9 to 1.7)930.58 (0.43 to 0.75)
 10–1935913129 97447157 (118 to 209)391.5% (1.1 to 2.1)700.67 (0.50 to 0.90)
 ≥2023662019 99153265 (203 to 347)392.7% (1.9 to 3.7)481.10 (0.82 to 1.44)
Adenoma histology¶<0.001
 Tubular65265652 39954103 (79 to 135)420.9% (0.7 to 1.3)1140.48 (0.36 to 0.62)
 Tubulovillous38493331 48969219 (173 to 277)572.4% (1.8 to 3.2)740.94 (0.73 to 1.19)
 Villous6606545317312 (194 to 501)133.0% (1.7 to 5.5)141.21 (0.70 to 1.93)
 Unknown5695522514268 (159 to 452)102.6% (1.4 to 5.0)111.23 (0.67 to 2.06)
Adenoma dysplasia**0.05
 Low grade98578579 296117148 (123 to 177)921.5% (1.2 to 1.8)1750.67 (0.55 to 0.80)
 High grade13891211 53928243 (168 to 351)252.7% (1.8 to 4.1)290.95 (0.63 to 1.38)
 Unknown358337319241 (126 to 464)51.8% (0.7 to 4.3)81.10 (0.50 to 2.09)
Proximal polyps††<0.001
 No61955351 44064124 (97 to 159)501.2% (0.9 to 1.7)1090.59 (0.45 to 0.75)
 Yes54094743 12690209 (170 to 257)722.1% (1.7 to 2.7)1030.87 (0.70 to 1.07)
No of APMPs and PMPs<0.001
 No APMPs, 1 PMP34022926 99727100 (69 to 146)231.1% (0.7 to 1.7)540.50 (0.33 to 0.73)
 No APMPs, 2–4 PMPs17481513 36217127 (79 to 205)111.0% (0.5 to 1.9)300.57 (0.33 to 0.91)
 No APMPs, ≥5 PMPs310325666234 (105 to 520)63.1% (1.4 to 7.2)60.95 (0.35 to 2.06)
 1 APMP, no other PMPs27862424 25934140 (100 to 196)281.5% (1.0 to 2.2)540.64 (0.44 to 0.89)
 ≥1 APMP, ≥2 total PMPs33582927 38270256 (202 to 323)542.4% (1.8 to 3.3)691.02 (0.79 to 1.29)
  • *Cumulative CRC incidence was estimated using the Kaplan-Meier method.

  • †P values were calculated with the log-rank test to compare cumulative CRC incidence among each category of the specified variable.

  • ‡Numbers of expected CRCs were calculated by multiplying the 5-year age-group and sex-specific observed person-years by the corresponding CRC incidence rates in the general population of England in 2007.

  • §PMP size was defined according to the largest PMP seen at baseline. Patients with PMPs of unknown size are not included in the table; in the analyses without surveillance, there were 59 such patients, of whom one was diagnosed with CRC; and in the analyses with one or more surveillance visits, there were 39 such patients with no CRC cases.

  • ¶Adenoma histology was defined according to the greatest degree of villousness seen at baseline.

  • **Adenoma dysplasia was defined according to the highest grade of dysplasia seen at baseline.

  • ††Proximal polyps were defined as those proximal to the descending colon.

  • APMP, advanced PMP; CRC, colorectal cancer; PMP, premalignant polyp; SIR, standardised incidence ratio.