Influence of long-term colonoscopic surveillance on incidence of colorectal cancer and death from the disease in patients with precursors (adenomas)

Figures & data

Table I.  2 041 patients and their adenomas at initial removal

	Men	Women
Age (years)
24–29	3	7
30–39	15	19
40–49	106	87
50–59	352	251
60–69	500	340
70–76	211	150
Number of adenomas
1	691	592
2	289	171
3 or more	207	91
Location
Rectum & sigmoid	889	695
Above sigmoid	106	74
Both	192	85
Diameter (largest in mm)
1–10	702	509
11–20	361	235
> 20	124	110
Dysplasia (most severe)
Mild	674	490
Moderate	402	281
Severe	111	83
Structure (most villous)
Tubular	912	609
Tubolovillous	265	226
Villous	10	19
Sessile >5 mm	202	153
Advanced adenoma
(>10 mm, villous, severe dysplasia)	497	362
Polypectomy (most extensive procedure)
Hot biopsy	187	143
Sling	931	647
Piecemeal	26	14
Excision	15	26
Resection	23	22
Unknown	5	2

Table II.  Planned surveillance according to adenoma morphology and time

Adenoma morphology	Years of inclusion	Interval strategy (months)	Patients
All pedunculated	1978–82 (RTC)*	6 versus 24 during	138
		5 years,
		then 12 versus 24
All pedunculated and small sessile and flat (≤5 mm)	1982–91 (RCT)*	24 versus 48	688
	1991–2002	36	836
Sessile >5 mm	1978–81	6 during 5 years then 12 6 versus 12 during 5 years then 12 versus 30	50
	1981–87 (RCT)*		117
	1988–2002 (RCT)*	12 versus 24	212
	Total		2041

*RCT: Randomisation of intervals

Table III.  2 041 patients under surveillance and cumulated number of patient years, colorectal examinations and neoplasia

	Time (months)
	24	48	72	96	120	192	240	288
Patients at risk	1979	1881	1737	1580	1362	687	315	115
Patients examined	1734	1624	1238	957	683	219	64	7
Years of surveillance	3412	6418	8821	10510	11754	13651	13946	13993
Colonoscopy	1333	3181	4139	4921	5398	6144	6265	6289
Complete	1209	2953	3865	4611	5056	5767	5881	5905
DCBE	199	487	641	781	853	969	992	998
Patients with adenomas	216	496	571	648	689	730	736	736
Patients with advanced adenomas	48	96	113	127	136	144	144	144
Patients with CRC	8	12	17	20	22	26	27	27

Table IV.  Patients with colorectal cancer during surveillance

Dukes’ stage	Number of patients
A	12 (10)*
B	8 (4)
C	5 (3)
Distant spread	2 (1)
Status at November 2002
Death from CRC	3
Death from other cause	4
Alive with CRC	3
Alive without CRC	17

*detected at planned examination in ()

Table V.  Incidence and mortality risks between 1978 and November 2002 in study group compared with standard Danish population

	Observed	Expected
Patient years	19 859
Men	11 155
Women	8 704
Patients with CRC	27	41.3
Men	14	26.1
Women	13	15.2
RR (95% CI)	0.65 (0.43–0.95)
Men	0.54 (0.29–0.90)
Women	0.86 (0.46–1.46)
Death from CRC	3	24.5
Men	2	15.5
Women	1	9.0
RR (95% CI)	0.12 (0.03–0.36)
Men	0.13 (0.02–0.47)
Women	0.11 (0.00–0.62)
Death from all causes	569	611.9
Men	381	393.0
Women	188	218.9
RR (95% CI)	0.93 (0.86–1.01)
Men	0.97 (0.87–1.07)
Women	0.86 (0.74–0.99)

Table VI.  Severe complications from surveillance

	Number of patients
Diagnostic colonic perforation (one death)	12
Therapeutic colonic perforation	3
Polypectomy syndrome	3
Severe bleeding after polypectomy	1
Coronary occlusion (lethal)	1