Background
Methods
Study populations
Data collection
Assessment of hair dye use and exercise status
Clinical characteristics
Statistical analysis
Sensitivity analysis
Results
Cases | Controls | All cases | ||||||
---|---|---|---|---|---|---|---|---|
Variables |
N = 296 |
N = 296 |
P-value |
N = 608 | ||||
N | (%) | N | (%) | N | (%) | Deatha (N = 48) | ||
Study site1 | ||||||||
South | 296 | (100.0) | 296 | (100.0) | 227 | (37.3) | 19 | |
North | - | - | 381 | (62.7) | 29 | |||
Age (yrs) | ||||||||
Mean ± SD | 71.3 ± 7.4 | 70.9 ± 8.0 | 0.622 | 71.6 ± 8.6 | ||||
<65 | 58 | (19.6) | 64 | (21.6) | 0.430 | 133 | (21.9) | 8 |
≥65 | 229 | (77.4) | 215 | (72.6) | 471 | (77.5) | 40 | |
Missing | 9 | 17 | 4 | |||||
BMI (kg/m2) | ||||||||
Mean ± SD | 24.2 ± 3.1 | 24.1 ± 3.2 | 0.742 | 24.3 ± 3.2 | ||||
<24 | 130 | (43.9) | 134 | (45.3) | 0.967 | 277 | (45.6) | 27 |
24– < 27 | 90 | (30.4) | 89 | (30.1) | 207 | (34.0) | 13 | |
≥27 | 41 | (13.9) | 43 | (14.5) | 98 | (16.1) | 5 | |
Missing | 35 | 30 | 26 | 3 | ||||
Education | ||||||||
<high school | 100 | (33.8) | 111 | (37.5) | 0.861 | 175 | (27.8) | 18 |
High school | 85 | (28.7) | 86 | (29.1) | 225 | (37.0) | 17 | |
>high school | 66 | (22.3) | 66 | (22.3) | 178 | (29.3) | 13 | |
Missing | 45 | 33 | 30 | 0 | ||||
Marital status* | ||||||||
Single/widowed/separated/divorced | 44 | (14.9) | 30 | (10.1) | 0.047* | 55 | (9.0) | 6 |
Married | 205 | (69.3) | 231 | (78.0) | 520 | (85.5) | 42 | |
Missing | 47 | 35 | 33 | |||||
Vasectomy | ||||||||
No | 215 | (72.6) | 199 | (67.2) | 0.628 | 516 | (84.9) | 39 |
Yes | 10 | (3.4) | 7 | (2.4) | 17 | (2.8) | 0 | |
Missing | 71 | 90 | 75 | 9 | ||||
Family history of PC | ||||||||
No | 226 | (76.4) | 245 | (82.8) | 0.243 | 523 | (86.0) | 43 |
Yes | 17 | (5.7) | 11 | (3.7) | 32 | (5.3) | 3 | |
Missing | 53 | 40 | 53 | |||||
Cigarette Smoking | ||||||||
No | 153 | (51.7) | 159 | (53.7) | 0.561 | 293 | (48.2) | 20 |
Yes | 143 | (48.3) | 135 | (45.6) | 315 | (51.8) | 28 | |
Missing | 0 | 2 | 0 | 0 | ||||
Alcohol drinking | ||||||||
No | 199 | (67.2) | 208 | (70.2) | 0.459 | 428 | (70.4) | 28 |
Yes | 95 | (32.1) | 87 | (29.4) | 179 | (29.4) | 20 | |
Missing | 2 | 1 | 1 | 0 | ||||
Betel nut chewing | ||||||||
No | 281 | (94.9) | 281 | (94.9) | 0.845 | 578 | (95.1) | 44 |
Yes | 13 | (4.4) | 12 | (4.1) | 28 | (4.6) | 3 | |
Missing | 2 | 3 | 2 | 1 | ||||
Clinical stageb
| ||||||||
Localized | 290 | (47.7) | 7 | |||||
Locally advanced | 158 | (26.0) | 7 | |||||
Bone metastasis | 154 | (25.3) | 34 | |||||
Missing | 6 | 0 | ||||||
Gleason score | ||||||||
<6 | 255 | (41.9) | 11 | |||||
7 | 191 | (31.4) | 12 | |||||
8-10 | 154 | (25.3) | 25 | |||||
Missing | 8 | 0 | ||||||
Preoperative PSA (ng/ml) | ||||||||
<10 | 152 | (25.0) | 5 | |||||
10- < 20 | 143 | (23.5) | 4 | |||||
≥20 | 295 | (48.5) | 38 | |||||
Missing | 18 | 1 |
Cases | Controls | Crude OR (95 % CI) | AOR (95 % CI)a
| AOR (95 % CI)b
| |||
---|---|---|---|---|---|---|---|
Variables |
N = 296 |
N = 296 | |||||
N | (%) | N | (%) | ||||
Hair dyes | |||||||
No | 197 | (66.6) | 231 | (78.0) | 1.00 | 1.00 | 1.00 |
Yes | 95 | (32.1) | 64 | (21.6) | 1.74 (1.21–2.53)* | 1.86 (1.21–2.82)* | 2.15 (1.32–3.57)* |
Missing | 4 | 1 | 4.69 (0.69–92.10) | 5.03 (0.73–98.83) | 5.40 (0.76–108.02) | ||
Age of first use (yrs) | |||||||
Never | 197 | (66.6) | 231 | (78.0) | 1.00 | 1.00 | 1.00 |
≥60 | 24 | (8.1) | 21 | (7.1) | 1.34 (0.72–2.49) | 1.23 (0.63–2.39) | 1.52 (0.71–3.30) |
50- < 60 | 28 | (9.5) | 21 | (7.1) | 1.56 (0.86–2.87)* | 2.19 (1.08–4.60)* | 2.64 (1.16–6.36)* |
<50 | 29 | (9.8) | 16 | (5.4) | 2.13 (1.14–4.11)* | 2.32 (1.21–4.61)* | 2.25 (1.01–5.19)* |
Missing | 18 | 7 | 3.02 (1.28–7.89) | 2.70 (1.04–7.86) | 4.29 (1.32–16.72) | ||
P for trend | <0.01 | <0.01 | <0.01 | ||||
Years of use (years) | |||||||
Never | 197 | (66.6) | 231 | (78.0) | 1.00 | 1.00 | 1.00 |
≤10 | 40 | (13.5) | 35 | (11.8) | 1.34 (0.82–2.20) | 1.49 (0.87–2.59) | 1.57 (0.82–3.03) |
>10 | 37 | (12.5) | 22 | (7.4) | 1.97 (1.13–3.50)* | 2.10 (1.15–3.92)* | 2.54 (1.23–5.41)* |
Missing | 22 | 8 | 3.22 (1.46–7.87) | 3.23 (1.36–8.52) | 5.43 (1.82–20.13) | ||
P for trend | 0.02 | <0.01 | <0.01 | ||||
Frequency of use (times per year) | |||||||
Never | 197 | (66.6) | 231 | (78.0) | 1.00 | 1.00 | 1.00 |
≤6 | 41 | (13.9) | 32 | (10.8) | 1.50 (0.91–2.49) | 1.64 (0.95–2.85) | 1.73 (0.91–3.32) |
>6 | 35 | (11.8) | 25 | (8.4) | 1.64 (0.95–2.86) | 1.97 (1.07–3.69)* | 2.65 (1.26–5.78)* |
Missing | 23 | 8 | 3.37 (1.53–8.19) | 2.82 (1.23–7.08) | 3.85 (1.41–11.74) | ||
P for trend | 0.02 | <0.01 | <0.01 | ||||
Year of first use | |||||||
No | 197 | (66.6) | 231 | (78.0) | 1.00 | 1.00 | 1.00 |
After 1980 | 5 | (1.7) | 3 | (1.0) | 1.95 (0.47–9.62) | 1.25 (0.23–6.83) | 0.89 (0.11–5.90) |
Before 1980 | 76 | (25.7 | 55 | (18.6) | 1.62 (1.09–2.41)* | 1.87 (1.21–2.90)* | 2.16 (1.28–3.68)* |
Missing | 18 | 7 | 3.02 (1.28–7.89) | 2.71 (1.04–7.89) | 4.32 (1.33–16.87) | ||
Regular exercise | |||||||
No | 126 | (42.6) | 120 | (40.5) | 1.00 | 1.00 | 1.00 |
Yes | 166 | (56.1) | 168 | (56.8) | 0.93 (0.67–1.28) | 0.99 (0.69–1.43) | 1.01 (0.64–1.59) |
Missing | 4 | 8 | 0.48 (0.02–5.03) | none | 1.03 (0.66–1.62) | ||
Frequency of exercise (times per week) | |||||||
No | 126 | (42.6) | 120 | (40.5) | 1.00 | 1.00 | 1.00 |
1-6 | 56 | (18.9) | 65 | (22.0) | 1.22 (0.79–1.89) | 0.94 (0.58–1.53) | 1.01 (0.55–1.86) |
≥7 | 110 | (37.2) | 103 | (34.8) | 0.98 (0.68–1.42) | 1.02 (0.68–1.54) | 0.97 (0.58–1.62) |
Missing | 4 | 8 | 0.48 (0.12–1.55) | 1.57 (0.25–12.15) | 0.97 (0.11–8.50) |
N | Total 608 | Prostate-cancer-specific death 48 | HR | (95 % CI) | AHRa
| (95 % CI) | |
---|---|---|---|---|---|---|---|
Variables | N (%) | N | |||||
Hair dyes | |||||||
No | 443 | (72.9) | 35 | 1.00 | 1.00 | ||
Yes | 161 | (54.4) | 13 | 0.89 | (0.45-1.65) | 1.14 | (0.47-2.59) |
Missing | 4 | 0 | |||||
Years of use | |||||||
Never | 443 | (72.9) | 35 | 1.00 | 1.00 | ||
≤10 years | 85 | (14.0) | 9 | 1.16 | (0.52-2.31) | 1.46 | (0.54-3.56) |
>10 years | 64 | (10.5) | 2 | 0.35 | (0.06-1.15) | 0.33 | (0.02-1.74) |
Missing | 16 | 2 | |||||
Frequency of use (times per year | |||||||
Never | 443 | (72.9) | 35 | 1.00 | 1.00 | ||
≤6 | 83 | (13.7) | 5 | 0.75 | (0.26-1.74) | 0.62 | (0.14-1.94) |
>6 | 63 | (10.4) | 7 | 1.07 | (0.43-2.28) | 2.15 | (0.70-6.03) |
Missing | 19 | 1 | |||||
Regular exercise | |||||||
No | 252 | (41.4) | 34 | 1.00 | 1.00 | ||
Yes | 353 | (58.1) | 14 | 0.27 | (0.14-0.50)* | 0.37 | (0.16-0.83)* |
Missing | 3 | 0 | |||||
Frequency of exercise (times per week) | |||||||
Never | 252 | (41.4) | 34 | 1.00 | 1.00 | ||
1-6 | 161 | (26.5) | 7 | 0.34 | (0.14-0.73)* | 0.66 | (0.22-1.82) |
≥7 | 188 | (30.9) | 6 | 0.20 | (0.08-0.45)* | 0.23 | (0.07-0.65)* |
Missing | 7 | 1 | |||||
Clinical stageb
| |||||||
Localized | 290 | (47.7) | 7 | 1.00 | 1.00 | ||
Locally advanced | 158 | (26.0) | 7 | 1.95 | (0.67-5.71) | 1.56 | (0.41-5.69) |
Bone metastasis | 154 | (25.3) | 34 | 12.10 | (5.64-29.99)* | 10.15 | (3.22-35.98* |
Missing | 6 | 0 |