Brief Articles
Copyright ©2009 The WJG Press and Baishideng.
World J Gastroenterol. May 28, 2009; 15(20): 2526-2530
Published online May 28, 2009. doi: 10.3748/wjg.15.2526
Table 1 Distributions of selected variables in colorectal cancer patients and cancer-free controls n (%)
VariablesTest group
Validation group
Merged group
P1
CaseControlCaseControlCaseControl
Age (yr)0.992
≤ 49120 (23.4)122 (23.3)36 (18.7)36 (18.0)156 (22.1)158 (21.9)
50-60146 (28.5)149 (28.5)39 (20.2)42 (21.0)185 (26.2)191 (26.4)
> 60247 (48.2)252 (48.2)118 (61.1)122 (61.0)365 (51.7)374 (51.7)
Sex0.937
Male300 (58.5)300 (57.4)137 (71.0)149 (74.5)437 (61.9)449 (62.1)
Female213 (41.5)223 (42.6)56 (29.0)51 (25.5)269 (38.1)274 (37.9)
Smoking status< 0.0001
Current228 (44.4)142 (27.2)88 (45.6)77 (38.5)316 (44.8)219 (30.3)
Former 59 (11.5) 79 (15.1)20 (10.4)24 (12.0)79 (11.2)103 (14.3)
Non226 (44.1)302 (57.7)85 (44.0)99 (49.5)311 (44.1)401 (55.5)
Drinking status< 0.0001
Current275 (53.6) 83 (15.9)98 (50. 8)57 (28.5)373 (52.8)140 (19.4)
Former14 (2.7)25 (4.8)12 (6.2)10 (5.0)26 (3.7)35 (4.8)
Non224 (43.7)415 (79.4)83 (43.0)133 (66.5)307 (43.5)548 (75.8)
Family history of cancer0.018
Yes 71 (13.8)57 (10.9)20 (10.4)8 (4.0)91 (12.9)65 (9.0)
No442 (86.2)466 (89.1)173 (89.6)192 (96.0)615 (87.1)658 (91.0)
BMI (kg/m2)0.002
≤ 23.9297 (57.9)346 (66.2)92 (47. 7)118 (59.0)389 (55.1)464 (64.2)
24.0-27.9169 (32.9)139 (26.6)77 (39.9)66 (33.0)246 (34.8)205 (28.4)
≥ 28.047 (9.2)38 (7.3)24 (12.4)16 (8.0)71 (10.1)54 (7.5)
Menstrual history0.881
Premenopause 43 (20.2)41 (18.4)10 (17.9)11 (21.6)53 (19.7)52 (19.0)
Menopause170 (79.8)182 (81.6)46 (82.1)40 (78.4)216 (80.3)222 (81.0)
1P value for two-sided χ2 test.
Table 2 Comparison of epidemiological factors for colorectal cancer
VariablesAdjusted OR (95% CI)1
Test groupValidation groupMerged group
Smoking status
Non  1.00 (ref.)1.00 (ref.)1.00 (ref.)
Former0.97 (0.52-1.80)0.66 (0.30-1.46)0.78 (0.49-1.23)
Current1.41 (0.82-2.43)0.79 (0.45-1.38)1.01 (0.69-1.48)
Trend test P value< 0.000010.187< 0.00001
Drinking status
Non  1.00 (ref.)1.00 (ref.)  1.00 (ref.)
Former2.02 (0.93-4.41)2.84 (1.03-7.81)2.30 (1.27-4.17)
Current14.69 (9.41-22.94)3.82 (2.23-6.56)8.61 (6.15-12.05)
Trend test P value< 0.000010.023< 0.00001
Family history of cancer
Negative  1.00 (ref.)  1.00 (ref.)  1.00 (ref.)
Positive1.43 (0.94-2.18)3.21 (1.31-7.84)1.62 (1.12-3.34)
BMI (kg/m2)
≤ 23.91.00 (ref.)1.00 (ref.) 1.00 (ref.)
≥ 24.01.34 (1.00-1.78)1.60 (1.05-2.44)1.39 (1.10-1.75)
1Adjusted for age, sex, smoking status, alcohol drinking, family history of cancer, BMI.
Table 3 Stratification analysis of colon and rectal cancer
VariablesAdjusted OR (95% CI)1
Test group
Validation group
Merged group
Colon cancer (n = 253)Rectal cancer (n = 260)Colon cancer (n = 95)Rectal cancer (n = 98)Colon cancer (n = 348)Rectal cancer (n = 358)
Smoking status
Non1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)
Former0.71 (0.34-1.49)1.26 (0.59-2.69)1.09 (0.44-2.72)0.41 (0.14-1.18)0.83 (0.48-1.43)0.79 (0.45-1.38)
Current1.34 (0.72-2.51)1.87 (0.96-3.65)1.03 (0.53-2.03)0.78 (0.40-1.51)1.22 (0.78-1.91)1.17 (0.75-1.83)
Drinking status
Non1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)
Former2.28 (0.90-5.76)1.32 (0.48-3.64)2.51 (0.78-8.06)3.10 (0.88-10.92)2.51 (1.24-5.07)1.71 (0.80-3.65)
Current13.24 (7.78-22.51)11.91 (7.14-19.87)3.46 (1.83-6.53)3.61 (1.94-6.74)7.60 (5.13-11.25)7.52 (5.13-11.01)
Family history of cancer
Negative1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)
Positive1.67 (1.01-2.75)1.26 (0.76-2.09)3.26 (1.12-9.45)3.52 (1.26-9.85)1.82 (1.17-2.82)1.51 (0.97-2.35)
BMI (kg/m2)
≤ 23.91.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)1.00 (ref.)
≥ 24.01.48 (1.05-2.09)1.22 (0.86-1.73)1.18 (0.70-1.99)2.00 (1.18-3.36)1.38 (1.04-1.83)1.35 (1.02-1.79)
1Adjusted for age, sex, smoking status, alcohol drinking, family history of cancer, BMI.