Table 4.
Association between uterine leiomyomata and endometrial cancer, by histological subtype, 1995–2013
| Type I cancers
|
Type II and III cancers
|
|||||||
|---|---|---|---|---|---|---|---|---|
| Exposure | Cases | Crude rate1 | Age- Adjusted IRR2 | 95% CI | Cases | Crude rate1 | Age- Adjusted IRR2 | 95% CI |
| History of UL | ||||||||
| No | 63 | 14.6 | 1.00 | Ref. | 14 | 3.3 | 1.00 | Ref. |
| Yes | 46 | 26.3 | 1.12 | 0.78, 1.59 | 37 | 14.3 | 3.13 | 1.64, 5.99 |
| Age at UL diagnosis (years) | ||||||||
| <30 | 10 | 15.9 | 1.08 | 0.55, 2.12 | 7 | 11.1 | 4.90 | 1.91, 12.57 |
| 30–39 | 24 | 20.6 | 1.09 | 0.68, 1.77 | 10 | 8.6 | 2.71 | 1.16, 6.29 |
| ≥40 | 34 | 43.3 | 1.15 | 0.74, 1.76 | 20 | 25.4 | 3.00 | 1.47, 6.10 |
| Years since UL diagnosis | ||||||||
| 0–2 | 13 | 35.2 | 3.87 | 2.07, 7.21 | 5 | 13.5 | 11.11 | 3.71, 33.27 |
| 3–9 | 9 | 12.5 | 0.75 | 0.37, 1.52 | 2 | 2.8 | 1.12 | 0.25, 5.09 |
| ≥10 | 37 | 29.5 | 0.90 | 0.60, 1.37 | 28 | 22.3 | 3.29 | 1.68, 6.46 |
UL=uterine leiomyomata, IRR=incidence rate ratio, CI=confidence interval.
1
Per 100,000 person-years
2
Adjusted for age and calendar time
3
Additionally adjusted for education, marital status, age at menarche, parity, menopausal status, oral contraceptive use, use of estrogen-only and estrogen+progesterone female hormones, smoking history, vigorous physical activity, and body mass index.