Table 2.
Association between number of sexual partners and prostate cancer risk in 976 cases and 1034 controls stratified by race/ethnicity
| Total | African-American | European-American | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Control N (%) | Case N (%) | Univariable OR (95% CI) | Multivariablea OR (95% CI) | P valuec | Control N (%) | Case N (%) | Univariable OR (95% CI) | Multivariableb OR (95% CI) | P valuec | Control N (%) | Case N (%) | Univariable OR (95% CI) | Multivariableb OR (95% CI) | P valuec | |
| When you were in your teens with how many different partners did you have intercourse? | |||||||||||||||
| 0–1 | 444 (46) | 347 (38) | Ref. | Ref. | 137 (30) | 113 (24) | Ref. | Ref. | 307 (60) | 234 (54) | Ref. | Ref. | |||
| 2–9 | 458 (47) | 456 (51) | 1.27 (1.05, 1.54) | 1.05 (0.84, 1.32) | 0.666 | 272 (60) | 281 (60) | 1.25 (0.93, 1.69) | 0.96 (0.68, 1.36) | 0.823 | 186 (36) | 175 (40) | 1.23 (0.94, 1.61) | 1.15 (0.84, 1.57) | 0.372 |
| 10 or more | 66 (7) | 99 (11) | 1.92 (1.36, 2.70) | 1.32 (0.89, 1.95) | 0.162 | 45 (10) | 71 (15) | 1.91 (1.22, 3.00) | 1.24 (0.75, 2.07) | 0.399 | 21 (4) | 28 (6) | 1.75 (0.97, 3.16) | 1.31 (0.67, 2.54) | 0.429 |
| Ptrend 0.000 | Ptrend 0.229 | Ptrend 0.006 | Ptrend 0.530 | Ptrend 0.028 | Ptrend 0.284 | ||||||||||
| When you were in your 20s with how many different partners did you have intercourse? | |||||||||||||||
| 0–1 | 308 (31) | 243 (26) | Ref. | Ref. | 80 (17) | 56 (12) | Ref. | Ref. | 228 (42) | 187 (39) | Ref. | Ref. | |||
| 2–9 | 526 (53) | 485 (51) | 1.17 (0.95, 1.44) | 1.14 (0.89, 1.46) | 0.291 | 281 (61) | 277 (58) | 1.41 (0.96, 2.06) | 1.45 (0.94, 2.23) | 0.092 | 245 (45) | 208 (44) | 1.04 (0.79, 1.35) | 1.04 (0.77, 1.40) | 0.816 |
| 10 or more | 167 (17) | 222 (23) | 1.68 (1.30, 2.19) | 1.41 (1.04, 1.92) | 0.027 | 100 (22) | 141 (30) | 2.01 (1.31, 3.09) | 1.82 (1.12, 2.97) | 0.015 | 67 (12) | 81 (17) | 1.47 (1.01, 2.15) | 1.27 (0.82, 1.97) | 0.282 |
| Ptrend 0.000 | P trend 0.029 | Ptrend 0.001 | P trend 0.017 | Ptrend 0.085 | Ptrend 0.345 | ||||||||||
| When you were in your 30s with how many different partners did you have intercourse? | |||||||||||||||
| 0–1 | 544 (54) | 412 (43) | Ref. | Ref. | 158 (34) | 102 (21) | Ref. | Ref. | 386 (71) | 310 (65) | Ref. | Ref. | |||
| 2–9 | 354 (35) | 402 (42) | 1.50 (1.24, 1.82) | 1.39 (1.11, 1.76) | 0.005 | 226 (49) | 274 (58) | 1.88 (1.38, 2.55) | 1.73 (1.22, 2.46) | 0.002 | 128 (24) | 128 (27) | 1.25 (0.93, 1.66) | 1.16 (0.84, 1.60) | 0.368 |
| 10 or more | 103 (10) | 137 (14) | 1.76 (1.32, 2.34) | 1.59 (1.14, 2.22) | 0.007 | 77 (17) | 99 (21) | 1.99 (1.35, 2.94) | 1.79 (1.15, 2.78) | 0.010 | 26 (5) | 38 (8) | 1.82 (1.08, 3.06) | 1.66 (0.93, 2.96) | 0.084 |
| Ptrend 0.000 | P trend 0.001 | Ptrend 0.000 | P trend 0.005 | Ptrend 0.012 | Ptrend 0.078 | ||||||||||
| Throughout your life, what is the total number of partners with whom you have had sexual intercourse? | |||||||||||||||
| <5 | 347 (34) | 260 (27) | Ref. | Ref. | 79 (17) | 56 (12) | Ref. | Ref. | 268 (50) | 204 (43) | Ref. | Ref. | |||
| 5–19 | 416 (41) | 388 (40) | 1.24 (1.01, 1.54) | 1.14 (0.88, 1.46) | 0.320 | 220 (46) | 211 (44) | 1.35 (0.92, 2.00) | 1.30 (0.83, 2.03) | 0.253 | 196 (36) | (37) | 1.19 (0.90, 1.56) | 1.08 (0.78, 1.48) | 0.646 |
| 20 or more | 254 (25) | 315 (33) | 1.66 (1.31, 2.08) | 1.47 (1.11, 1.95) | 0.007 | 177 (37) | 216 (45) | 1.72 (1.16, 2.56) | 1.57 (0.99, 2.48) | 0.053 | 77 (14) | 99 (21) | 1.69 (1.19, 2.39) | 1.58 (1.06, 2.35) | 0.025 |
| Ptrend 0.000 | P trend 0.006 | Ptrend 0.005 | P trend 0.046 | Ptrend 0.004 | P trend 0.040 | ||||||||||
OR odds ratio, 95% CI 95% confidence interval
aUnconditional logistic regression adjusted for body mass index at study enrollment (BMI, kg m−2), age at study entry, education (high school or less, some college, college, professional school), family history of prostate cancer (first degree relatives,
yes/no), smoking history (never, former, current), condom use (usually use, yes/no), aspirin use (regular user, yes/no), IFNL4 rs368234815 genotype (ΔG/ΔG or ΔG/TT vs. TT/TT), and race
bUnconditional logistic regression adjusted for body mass index at study enrollment (BMI, kg m−2), age at study entry, education (high school or less, some college, college, professional school), family history of prostate cancer (first degree relatives,
yes/no), smoking history (never, former, current), condom use (usually use, yes/no), aspirin use (regular user, yes/no), and IFNL4 rs368234815 genotype (ΔG/ΔG or ΔG/TT vs. TT/TT)
Bolded data indicate significant associations in the multivariable logistic regression analysis
cBonferroni-corrected significance thresholds for multiple comparisons in the total (n = 4) and stratified (n = 8) analyses are 0.0125 and 0.00625, respectively