Table 5. Associations between unopposed oestrogen therapy and oestrogen plus progestin therapy and ovarian cancer by histology, NIH-AARP Diet and Health Study Cohort, 1995–2006.
|
Serous cases (
n
=228)
|
Other cases (
n
=198)
|
|||||
|---|---|---|---|---|---|---|
| Number of cancers | Person-years | HRa (95% CI) | No. of cancers | Person-years | HRa (95% CI) | |
| Among women with a hysterectomy at baseline (n=23 584) | ||||||
| No MHT use | 8 | 55 796 | 1.00 (reference) | 15 | 55 839 | 1.00 (reference) |
| ET only | 43 | 116 004 | 2.82 (1.31, 6.04) | 33 | 115 930 | 1.02 (0.56, 1.84) |
| Duration of use (years) | ||||||
| <10 | 17 | 58 341 | 2.20 (0.94, 5.15) | 10 | 58 310 | 0.72 (0.32, 1.62) |
| ⩾10 | 26 | 55 796 | 3.32 (1.49, 7.44) | 23 | 55 753 | 1.52 (0.78, 2.96) |
| Among women with an intact uteri at baseline (n=68 596) | ||||||
| No MHT use | 73 | 315 892 | 1.00 (reference) | 78 | 315 883 | 1.00 (reference) |
| EPT only | 61 | 170 392 | 1.83 (1.28, 2.61) | 37 | 170 265 | 1.05 (0.70, 1.58) |
| Duration of EPT only use (years) | ||||||
| <10 | 43 | 126 355 | 1.73 (1.16, 2.56) | 24 | 126 235 | 0.92 (0.57, 1.49) |
| ⩾10 | 18 | 43 697 | 1.97 (1.17, 3.34) | 13 | 43 691 | 1.37 (0.76, 2.50) |
| Regimen of EPT only use | ||||||
| Sequential | 21 | 56 571 | 1.87 (1.14, 3.08) | 15 | 56 545 | 1.31 (0.74, 2.31) |
| Continuous | 33 | 83 334 | 2.02 (1.32, 3.08) | 15 | 83 223 | 0.87 (0.49, 1.53) |
Abbreviations: CI=confidence interval; EPT=oestrogen plus progestin therapy; ET=unopposed oestrogen therapy; HR, hazard ratio; MHT=menopausal hormone therapy; NIH-AARP=National Institutes of Health-AARP; RR=hazard rate ratio.
a
HR adjusted for continuous age (years), race (white, other/unknown), parity (nulliparous, 1, 2, 3+, unknown), duration of oral contraceptive use (none, <10 years, ⩾10 years, or unknown), and body mass index (<25, 25–29.9, ⩾30 kg m−2, or unknown); models also contained terms for other formulations of menopausal hormone use and unknown use.