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. Author manuscript; available in PMC: 2013 Jun 18.
Published in final edited form as: Gastroenterology. 2008 Dec 9;136(3):832–841. doi: 10.1053/j.gastro.2008.12.007

Table 4.

Risk of New Neoplasia at Follow-up, according to Baseline Patient and Adenoma Characteristics

Characteristic Number (%) Non-advanced adenoma % (95% CI) Advanced adenoma % (95% CI) Cancer % (95% CI)

Age, y
 < 40 154 (1.7) 18.8 (12.7–25.0) 3.9 (0.8–7.0) 0.0
 40–49 804 (8.8) 27.7 (24.6–30.8) 6.3 (4.7–8.0) 0.1 (0.0–0.4)
 50–59 2397 (26.1) 34.9 (33.0–36.8) 8.6 (7.5–9.8) 0.3 (0.1–0.6)
 60–69 3676 (40.1) 36.0 (34.4–37.5) 12.2 (11.1–13.2) 0.6 (0.3–0.8)
 70–79 2074 (22.6) 36.9 (34.9–39.0) 14.5 (13.0–16.0) 1.3 (0.8–1.7)
 80+ 62 (0.7) 33.9 (22.1–45.7) 17.7 (8.2–27.3) 1.6 (0.0–4.7)

Sex
 Female 2642 (28.8) 29.0 (27.3–30.7) 9.8 (8.7–10.9) 0.3 (0.1–0.5)
 Male 6525 (71.2) 37.3 (36.1–38.4) 11.7 (10.9–12.5) 0.8 (0.6–1.0)

Race
 White 8166 (89.1) 35.0 (34.0–36.1) 11.4 (10.7–12.0) 0.6 (0.4–0.8)
 Black 527 (5.7) 37.6 (33.4–41.7) 10.4 (7.8–13.0) 0.8 (0.0–1.5)
 Other 474 (5.2) 29.1 (25.0–33.2) 8.9 (6.3–11.4) 1.3 (0.3–2.3)

Family history of colorectal cancera
 No 6547 (71.4) 34.5 (33.4–35.7) 11.0 (10.3–11.8) 0.6 (0.4–0.8)
 Yes 2089 (22.8) 36.7 (34.6–38.7) 11.6 (10.3–13.0) 0.6 (0.3–0.9)
 Unknown 531 (5.8) 32.2 (28.2–36.2) 11.1 (8.4–13.8) 1.3 (0.3–2.3)

Cigarette smoking statusb
 Never 2805 (34.1) 33.6 (31.9–35.4) 11.1 (9.9–12.2) 0.5 (0.2–0.8)
 Former 4081 (49.6) 36.9 (35.4–38.4) 12.1 (11.1–13.1) 0.9 (0.6–1.2)
 Current 1299 (15.8) 36.8 (34.2–39.4) 11.8 (10.0–13.5) 0.2 (0.0–0.5)
 Unknown 43 (0.5) 34.9 (20.6–49.1) 9.3 (0.6–18.0) 2.3 (0.0–6.8)

Body mass index (kg/m 2) c, d
 <25 2332 (28.4) 32.2 (30.3–34.1) 11.7 (10.4–13.1) 0.5 (0.2–0.8)
 25–<30 3771 (45.9) 36.6 (35.0–38.1) 11.6 (10.6–12.7) 0.7 (0.4–1.0)
 30+ 2110 (25.7) 38.1 (36.0–40.2) 11.6 (10.2–12.9) 0.8 (0.4–1.2)

Previous Polype
 No Yes 6941 (75.7) 33.4 (32.3–34.5) 9.8 (9.1–10.5) 0.6 (0.4–0.8)
 Unknown 2057 (22.4) 39.5 (37.4–41.6) 15.2 (13.7–16.8) 0.8 (0.4–1.2)
169 (1.8) 38.5 (31.1–45.8) 16.6 (11.0–22.2) 0.6 (0.0–1.7)

Adenoma Numberf
 1 5465 (60.0) 30.2 (29.0–31.4) 8.6 (7.8–9.3) 0.5 (0.4–0.7)
 2 2054 (22.5) 38.3 (36.2–40.4) 12.7 (11.3–14.1) 0.5 (0.2–0.9)
 3 890 (9.8) 45.4 (42.1–48.7) 15.3 (12.9–17.6) 1.1 (0.4–1.8)
 4 326 (3.6) 45.4 (40.0–50.8) 19.6 (15.3–23.9) 1.2 (0.0–2.4)
 5+ 377 (4.1) 51.2 (46.1–56.2) 24.1 (19.8–28.5) 0.8 (0.0–1.7)

Adenoma location
 Distal colorectum 4434 (48.4) 30.4 (29.1–31.8) 8.5 (7.7–9.3) 0.4 (0.2–0.6)
 Proximal only 2620 (28.6) 37.3 (35.4–39.1) 11.8 (10.6–13.1) 0.8 (0.5–1.2)
 Proximal and distal 1754 (19.1) 44.2 (41.9–46.6) 17.5 (15.7–19.3) 1.0 (0.6–1.5)
 Unknown 359 (3.9) 26.7 (22.2–31.3) 8.1 (5.3–10.9) 0.0

Adenoma sizeg
 <5mm 2540 (28.8) 36.4 (34.5–38.3) 7.7 (6.6–8.7) 0.5 (0.2–0.8)
 5–<10 mm 3115 (35.3) 36.8 (35.1–38.5) 8.7 (7.7–9.7) 0.5 (0.2–0.7)
 10–<20mm 2487 (28.2) 31.4 (29.6–33.3) 15.9 (14.5–17.4) 0.8 (0.5–1.2)
 20+ mm 672 (7.6) 31.8 (28.3–35.4) 19.3 (16.4–22.3) 1.2 (0.4–2.0)

Adenoma histology
 Tubularh 7268 (79.3) 35.1 (34.0–36.2) 9.7 (9.0–10.4) 0.6 (0.4–0.7)
 Tubulovillous/villousi 1899 (20.7) 33.9 (31.8–36.0) 16.8 (15.1–18.5) 0.9 (0.5–1.4)

High-grade dysplasiaj
 No 6485 (90.5) 35.3 (34.2–36.5) 10.6 (9.8–11.3) 0.5 (0.4–0.7)
 Yes 683 (9.5) 35.9 (32.3–39.5) 16.0 (13.2–18.7) 1.3 (0.5–2.2)

Low-risk groupk 4644 (50.7) 34.5 (33.1–35.8) 6.9 (6.2–7.6) 0.5 (0.3–0.7)
High-risk group 4523 (49.3) 35.3 (33.9–36.7) 15.5 (14.5–16.6) 0.8 (0.5–1.0)
a

Percent of patients with a particular outcome reported during surveillance + standard error.

b

History of colorectal cancer in one or more parent, sibling, or child.

c

No data available for National Polyp Study participants (n=939)

d

Excludes 15 participants with missing data.

e

History of previous polyps or adenomas prior to qualifying colonoscopy; National Polyp Study and VA Cooperative Study included only participants with a first-time adenoma (n=1810).

f

Number of adenomas detected at qualifying examination; excludes 55 participants with missing data.

g

Size of largest adenoma; excludes 353 participants with missing data.

h

Includes participants with adenomas where histology was not specified, unknown, or other histologies (n=957).

i

One or more adenoma(s) with greater than 25% villous features.

j

One or more adenoma(s) with high-grade dysplasia. No data available for 1999 Calcium Polyp Prevention Study and Aspirin Folate Trial participants.

k

Defined according to the most recent surveillance guidelines3. The low-risk group includes patients with 1 to 2 small (less than 1 cm), tubular adenoma(s) with low-grade dysplasia; the high-risk group includes patients with 3 or more adenomas, or any adenomas 1 cm or larger in size, or with greater than 25% villous features, or with high-grade dysplasia.