Table 4

Risk factors associated with metachronous advanced neoplasia

Risk factors at randomisation2-examination group (n=701)1-examination group (n=763)Both groups (n=1464)
No (%) with AN*/No PtsOR (95% CI)No (%) with AN/No PtsOR (95% CI)No (%) with AN/No PtsOR (95% CI)
No of adenomas†2.25 (0.55 to 8.35)3.58 (1.15 to 11.11)2.84 (1.37 to 5.91)
1–26/343 (1.7)5/395 (1.3)11/738 (1.5)
3–41/187 (0.5)3/197 (1.5)4/384 (1.0)
≥55/171 (2.9)8/171 (4.7)13/342 (3.8)
Size of largest adenoma‡1.59 (0.39 to 5.87)2.25 (0.72 to 6.96)1.94 (0.84 to 4.40)
Small (≤5 mm)5/246 (2.0)5/262 (1.9)10/508 (2.0)
Medium (6–9 mm)2/236 (0.8)3/263 (1.1)5/499 (1.0)
Large (≥10 mm)5/219 (2.3)8/238 (3.4)13/457 (2.8)
Morphology§
Polypoid (≥10 mm)1.08 (0.19 to 4.38)1.06 (0.25 to 3.55)1.06 (0.38 to 2.63)
Absent9/535 (1.7)12/580 (2.1)21/1115 (1.9)
Present3/166 (1.8)4/183 (2.2)7/349 (2.0)
Flat (<10 mm)0.99 (0.26 to 4.54)3.04 (1.01 to 12.11)
Absent4/232 (1.7)0/255 (0)4/487 (0.8)
Present8/469 (1.7)16/508 (3.1)24/977 (2.5)
Depressed2.55 (0.06 to 18.34)1.63 (0.04 to 10.52)
Absent12/688 (1.7)15/743 (2.0)27/1431 (1.9)
Present0/13 (0)1/20 (5.0)1/33 (3.0)
LST-G1.60 (0.36 to 11.57)0.77 (0.02 to 4.84)
Absent11/663 (1.7)16/734 (2.2)27/1397 (1.9)
Present1/38 (2.6)0/29 (0)1/67 (1.5)
LST-NG3.04 (0.07 to 22.84)10.16 (2.59 to 33.84)6.61 (2.11 to 17.61)
Absent11/680 (1.6)11/726 (1.5)22/1406 (1.6)
Present1/21 (4.8)5/37 (13.5)6/58 (10.3)
Pathologically advanced adenomas¶1.20 (0.30 to 4.45)2.81 (0.91 to 9.50)1.92 (0.92 to 4.00)
Absent7/439 (1.6)6/475 (1.3)13/914 (1.4)
Present5/262 (1.9)10/288 (3.5)15/550 (2.7)
Large serrated lesion (≥10 mm, Rt-sided**)
Absent12/693 (1.7)16/755 (2.1)28/1448 (1.9)
Present0/8 (0)0/8 (0)0/16 (0)
Age1.18 (0.32 to 4.76)2.88 (0.86 to 12.36)1.88 (0.86 to 4.13)
<60 years5/320 (1.6)4/370 (1.1)9/690 (1.3)
≥60 years7/381 (1.8)12/393 (3.1)19/774 (2.5)
Gender1.01 (0.27 to 4.63)1.67 (0.50 to 7.16)1.32 (0.56 to 3.00)
Female4/235 (1.7)4/271 (1.5)8/506 (1.6)
Male8/466 (1.7)12/492 (2.4)20/958 (2.1)
Family history of CRC††2.78 (0.60 to 10.59)2.23 (0.51 to 7.55)2.39 (1.07 to 5.35)
Absent8/592 (1.4)12/662 (1.8)20/1254 (1.6)
Present4/109 (3.7)4/101 (4.0)8/210 (3.8)
  • *Any lesion with low-grade dysplasia ≥10 mm, high-grade dysplasia.

  • †OR; number of adenomas (≥5 vs ≤4).

  • ‡OR; size of largest adenoma (≥10 mm vs ≤9 mm).

  • §Polypoid; 0-Ip, 0-Isp, 0-Is type, Flat; 0-IIa type, Depressed; 0-IIa+IIc, 0-IIc type.

  • ¶Any low-grade dysplasia ≥10 mm, high-grade dysplasia.

  • **Caecum, ascending colon, transverse colon.

  • ††First-degree relatives.

  • CRC, colorectal cancer; LST-G, laterally spreading tumour, granular type; LST-NG, laterally spreading tumour, non-granular type.