Table 2. Risk of ovarian cancer associated with NSAID use overall and stratified by oral contraceptive use and parity.
| Cases | Controls | Cases | Controls | ||||
|---|---|---|---|---|---|---|---|
| NSAID use | N (%) | N (%) | OR (95% CI)a | N (%) | N (%) | OR (95% CI)a,b | P-interaction |
| Overall | |||||||
| Never use | 336 (70.7) | 1711 (65.7) | 1.00 (Referent) | ||||
| Ever use | 139 (29.3) | 893 (34.3) | 0.74 (0.59–0.92) | ||||
| Former | 45 (9.6) | 220 (8.6) | 0.96 (0.67–1.37) | ||||
| Current | 90 (19.1) | 637 (24.8) | 0.68 (0.52–0.88) | ||||
| Aspirin only | 64 (16.0) | 396 (18.8) | 0.73 (0.54–1.00) | ||||
| Ibuprofen only | 59 (14.9) | 424 (19.9) | 0.68 (0.50–0.93) | ||||
| Duration (years) | |||||||
| <1 | 29 (6.1) | 189 (7.3) | 0.74 (0.49–1.14) | ||||
| 1–4 | 50 (10.5) | 378 (14.5) | 0.64 (0.46–0.88) | ||||
| 5–9 | 30 (6.3) | 150 (5.8) | 0.94 (0.61–1.44) | ||||
| ⩾10 | 30 (6.3) | 176 (6.8) | 0.78 (0.50–1.19) | ||||
| P-trend | 0.03 | ||||||
| Never used oral contraceptives | Ever used oral contraceptives | ||||||
| (n=276) | (n=1483) | (n=222) | (n=1669) | ||||
| Never use | 189 (74.1) | 758 (63.7) | 1.0 (Referent) | 144 (66.4) | 935 (67.4) | 1.0 (Referent) | |
| Ever use | 66 (25.9) | 432 (36.3) | 0.58 (0.42–0.80) | 73 (33.6) | 453 (32.6) | 0.98 (0.71–1.35) | 0.03 |
| Former | 18 (7.1) | 94 (8.0) | 0.69 (0.40–1.20) | 27 (12.6) | 125 (9.1) | 1.32 (0.82–2.12) | 0.1 |
| Current | 46 (18.2) | 321 (27.4) | 0.56 (0.39–0.80) | 44 (20.5) | 309 (22.6) | 0.85 (0.58–1.26) | |
| Aspirin only | 38 (15.0) | 218 (18.4) | 0.63 (0.42–0.93) | 26 (12.0) | 175 (12.7) | 0.97 (0.60–1.57) | 0.04 |
| Ibuprofen only | 20 (7.9) | 180 (15.2) | 0.45 (0.27–0.75) | 39 (18.1) | 239 (17.3) | 0.95 (0.63–1.43) | |
| Duration (years) | |||||||
| <1 | 15 (5.9) | 89 (7.5) | 0.67 (0.37–1.21) | 14 (6.5) | 98 (7.1) | 0.89 (0.48–1.65) | 0.04 |
| 1–4 | 20 (7.8) | 188 (15.8) | 0.42 (0.26–0.69) | 30 (13.8) | 187 (13.5) | 0.96 (0.61–1.49) | |
| 5–9 | 14 (5.5) | 76 (6.4) | 0.62 (0.33–1.14) | 16 (7.4) | 72 (5.2) | 1.56 (0.86–2.85) | |
| ⩾10 | 17 (6.7) | 79 (6.6) | 0.82 (0.46–1.45) | 13 (6.0) | 96 (6.9) | 0.71 (0.36–1.39) | |
| P-trend | 0.008 | 0.85 | |||||
| Nulliparous | Parous | ||||||
| (n=110) | (n=382) | (n=392) | (n=2811) | ||||
| Never use | 79 (78.2) | 197 (64.4) | 1.0 (Referent) | 257 (68.7) | 1514 (66.0) | 1.0 (Referent) | |
| Ever use | 22 (21.8) | 109 (35.6) | 0.47 (0.27–0.82) | 117 (31.3) | 781 (34.0) | 0.81 (0.64–1.04) | 0.05 |
| Former | 6 (6.0) | 32 (10.6) | 0.42 (0.16–1.08) | 39 (10.5) | 188 (8.3) | 1.15 (0.78–1.68) | 0.1 |
| Current | 15 (15.0) | 72 (23.9) | 0.48 (0.25–0.94) | 75 (20.2) | 562 (24.8) | 0.72 (0.54–0.96) | |
| Aspirin only | 8 (7.9) | 40 (13.2) | 0.48 (0.20–1.11) | 56 (15.1) | 355 (15.5) | 0.78 (0.57–1.09) | 0.3 |
| Ibuprofen only | 12 (11.9) | 60 (19.8) | 0.45 (0.22–0.92) | 47 (12.7) | 362 (15.8) | 0.77 (0.55–1.08) | |
| Duration (years) | |||||||
| <1 | 7 (6.9) | 20 (6.5) | 0.80 (0.32–2.03) | 22 (5.9) | 167 (7.3) | 0.75 (0.46–1.20) | 0.03 |
| 1–4 | 6 (5.9) | 51 (16.7) | 0.30 (0.12–0.74) | 44 (11.8) | 326 (14.2) | 0.72 (0.51–1.03) | |
| 5–9 | 4 (4.0) | 17 (5.6) | 0.54 (0.17–1.74) | 26 (7.0) | 133 (5.8) | 1.06 (0.67–1.67) | |
| ⩾10 | 5 (5.0) | 21 (6.9) | 0.47 (0.15–1.48) | 25 (6.7) | 155 (6.8) | 0.88 (0.55–1.39) | |
| P-trend | 0.01 | 0.25 | |||||
a
Adjusted for age, year of interview, state of residence, tubal ligation, family history of ovarian cancer, hysterectomy and menopausal status.
b
Each analysis is adjusted for the other two variables in the table.