Prevalence of colorectal neoplasms in young, average risk individuals: A turning tide between East and West

Table 1 Group size, mean age and male percentage according to age study group

Age study group	40-49 yr	50-59 yr	Total
Number of subjects	505	1245	1750
Mean age (yr) at colonoscopy (SD)	45.30 (2.81)	54.64 (2.83)	51.94 (5.09)
Male percentage (%)	55	51.2	52.3

Table 2 Comparison of detection rates of neoplastic findings on primary screening between subjects aged 40-49 and subjects aged 50-59 years, according to gender n (%)

Gender finding type	40-49 yr	50-59 yr	Total	P value1	OR (95%CI)
All
Total colonoscopies	505	1245	1750
Adenomatous polyps	42 (8.3)	170 (13.7)	212 (12.1)	0.002	1.74 (1.22-2.49)
Advanced adenoma	5 (1.0)	30 (2.4)	35 (2.0)	0.060	2.47 (0.95-6.40)
Cancer	1 (0.2)	3 (0.2)	4 (0.2)	1.000	1.22 (0.13-11.73)
Men
Total colonoscopies	278	638	916
Adenomatous polyps	23 (8.3)	106 (16.6)	129 (14.1)	0.001	2.21 (1.37-3.55)
Advanced adenoma	1 (0.4)	22 (3.4)	23 (2.5)	0.005	9.89 (1.33-73.76)
Cancer	1 (0.4)	2 (0.3)	3 (0.3)	1.000	0.87 (0.08-9.65)
Women
Total colonoscopies	227	607	834
Adenomatous polyps	19 (8.4)	64 (10.5)	83 (10.0)	0.435	1.29 (0.76-2.21)
Advanced adenoma	4 (1.8)	8 (1.3)	12 (1.4)	0.744	0.75 (0.22-2.50)
Cancer	0 (0.0)	1 (0.2)	1 (0.1)	1.000	1

¹χ² statistical comparison of distribution of selected findings.

Table 3 Studies reporting detection rates of adenoma and advanced lesion among average risk individuals aged 40-49 and 50-59 years

Ref.	Country of origin	Year published	Number of subjects in age group
			40-49 yr	50-59 yr
Western origin
de Jong et al[17]	the Netherlands	2005	90	36
Regula et al[8]	Poland	2006	2392	37313
Boursi et al[18]	Israel	2009	262	672
Current study	Israel	-	505	1245
Strul et al[4]	Israel	2006	183	409
Imperiale et al[6]	United States	2002	906	1533
Thoma et al[19]	United States	2010	247	747
Rundle et al[20]	United States	2008	553	352
Studies of Western origin (8)			5138	40774
Asian origin
Hemmasi et al[21]	Iran	2014	333	407
Chiu et al[22]	Taiwan (China)	2005	654	592
Chiu et al[23]	Taiwan (China)	2008	4161	4211
Liu et al[24]	Taiwan (China)	2005	2656	1903
Choe et al[25]	South Korea	2006	1875	1587
Hong et al[26]	South Korea	2010	1049	712
Kim et al[27]	South Korea	2013	4550	4436
Chung et al[28]	South Korea	2009	1930	2716
Park et al[29]	South Korea	2009	1057	1207
Ko et al[30]	South Korea	2012	1200	1038
Studies of Asian origin (9)			19465	18807
All studies (17)			24603	59581

Table 4 Odds ratio for colorectal neoplasia detection among individuals aged 50-59 years compared to those aged 40-49 according to country of origin

Finding	OR (95%CI)	P value1
Studies of Western origin
Overall adenomas	1.7 (1.53-1.88)	< 0.0001
Advanced adenoma	2.34 (1.95-2.81)	< 0.0001
Cancer	2.33 (1.45-3.75)	< 0.0001
Studies of Asian origin
Overall adenomas	1.99 (1.89-2.09)	< 0.0001
Advanced adenoma	2.36 (2.05-2.72)	< 0.0001
Cancer	3.88 (2.41-6.23)	< 0.0001
Total
Overall adenomas	1.25 (1.20-1.30)	< 0.0001
Advanced adenoma	2.65 (2.38-2.94)	< 0.0001
Cancer	3.39 (2.45-4.68)	< 0.0001

¹χ² statistical comparison of distribution of selected findings.