Table 3.
Cross-classification of seropositivity to C. trachomatis and other sexually transmitted infections and risk of ovarian cancer: results from the NHS and NHSII
| Control, n | All cases | Invasive EOC | |||||
|---|---|---|---|---|---|---|---|
| Case, n | RRa | 95% CI | Case, n | RRa | 95% CI | ||
| C. trachomatis (CT) and M. genitalium (MG) | |||||||
| CT− and MG− | 291 | 263 | Ref. | 203 | Ref. | ||
| CT+ and MG− | 37 | 57 | 1.89 | 1.11–3.20 | 43 | 1.79 | 1.08–2.97 |
| CT− and MG+ | 6 | 8 | 1.12 | 0.34–3.74 | 5 | 0.93 | 0.26–3.31 |
| CT+ and MG+ | 3 | 9 | 4.38 | 1.03–18.56 | 6 | 5.74 | 1.23–26.72 |
| CT and herpes simplex virus, type 2 (HSV2) | |||||||
| CT− and HSV2− | 276 | 253 | Ref. | 197 | Ref. | ||
| CT+and HSV2− | 32 | 46 | 1.85 | 1.06–3.24 | 34 | 1.67 | 0.97–2.87 |
| CT− and HSV2+ | 21 | 18 | 1.01 | 0.50–2.03 | 11 | 0.73 | 0.33–1.62 |
| CT+ and HSV2+ | 8 | 20 | 2.90 | 1.14–7.37 | 15 | 3.26 | 1.25–8.51 |
| CT and HSV and MG | |||||||
| CT− and HSV2− and MG− | 272 | 245 | Ref. | 192 | Ref. | ||
| CT+ and HSV2− and MG− | 30 | 41 | 1.77 | 0.98–3.18 | 32 | 1.64 | 0.94–2.85 |
| CT− and (HSV2+ or MG+) | 25 | 26 | 1.19 | 0.63–2.23 | 16 | 0.90 | 0.45–1.81 |
| CT+ and (HSV2+ or MG+) | 10 | 25 | 3.04 | 1.29–7.21 | 17 | 3.25 | 1.33–7.96 |
| CT and HSV and MG and human papillomavirus (HPV) 16 E6, HPV18 E6+E7, or HPV45 E6+E7 | |||||||
| Negative for all | 270 | 237 | Ref. | 186 | Ref. | ||
| CT+ only | 29 | 41 | 1.88 | 1.03–3.42 | 32 | 1.73 | 0.99–3.03 |
| MG+, HSV2+ or HPV+ only | 27 | 34 | 1.34 | 0.80–2.24 | 22 | 1.19 | 0.64–2.24 |
| CT+ and any other infection | 11 | 25 | 2.74 | 1.20–6.27 | 17 | 3.01 | 1.26–7.18 |
CT and HPV combination not evaluated, 0 cases and 3 controls positive for both infections
CI confidence interval, EOC epithelial ovarian cancer, NHS Nurses’ Health Study, RR relative risk
aConditional logistic regression models for all cases; all other results are from unconditional logistic regression models additionally controlling for matching factors (year of birth (±1 year), menopausal status at diagnosis (premenopausal, postmenopausal, unknown), and factors at one or both blood draws: menopausal status (premenopausal, postmenopausal, unknown), month of collection (±1 month), time of day (±2 h), fasting status (>8, ≤8 h), and postmenopausal hormone use (yes/no). Premenopausal NHSII cases and controls additionally matched on luteal day at blood collection (date of next menstrual cycle minus date of blood draw, ±1 day)). All adjusted models adjusted for: parity (nulliparous, 1 pregnancy, 2 pregnancies, 3 pregnancies, 4 + pregnancies), oral contraceptive use (never, <1 year, 1–5 years, 5+ years), tubal ligation (yes, no), marital status (never, married/domestic partnership/living with partner, divorced/separated, widowed), and weight change between ages 18 years and blood collection (kg, continuous)