Table 6.
Associations Between Age at Menarche and Type of and Age at Menopause and Adenocarcinoma, NIH-AARP Diet and Health Study Cohort, 1995–2006
| Characteristic | Never smokers | Former smokers | Current smokers | ||||||
|---|---|---|---|---|---|---|---|---|---|
| # cancers | RR* | 95% CI | # cancers | RR* | 95% CI | # cancers | RR* | 95% CI | |
| Age at menarche | |||||||||
| <11 | 12 | 1.00 | (referent) | 50 | 1.00 | (referent) | 55 | 1.00 | (referent) |
| 11–12 | 81 | 0.97 | 0.53 1.78 | 301 | 0.88 | 0.65 1.19 | 279 | 0.84 | 0.63 1.13 |
| 13–14 | 75 | 0.87 | 0.47 1.60 | 296 | 0.84 | 0.62 1.14 | 232 | 0.69 | 0.52 0.93 |
| 15+ | 13 | 0.67 | 0.30 1.47 | 55 | 0.71 | 0.48 1.04 | 62 | 0.75 | 0.52 1.08 |
| Missing | 0 | 4 | 1.24 | 0.43 3.54 | 4 | 1.28 | 0.44 3.69 | ||
| p-value for trend | 0.20 | 0.09 | 0.02 | ||||||
| Age at natural menopause | |||||||||
| <45 years | 11 | 1.09 | 0.56 2.09 | 64 | 1.30 | 0.98 1.73 | 72 | 1.43 | 1.06 1.92 |
| 45–49 years | 24 | 0.98 | 0.60 1.60 | 123 | 1.12 | 0.89 1.41 | 128 | 1.34 | 1.04 1.72 |
| 50–54 years | 49 | 1.00 | (referent) | 180 | 1.00 | (referent) | 118 | 1.00 | (referent) |
| 55+ years | 11 | 0.86 | 0.45 1.65 | 28 | 0.66 | 0.45 0.99 | 29 | 1.50 | 1.00 2.25 |
| p-value for trend† | 0.66 | <0.01 | 0.10 | ||||||
| Age at bilateral oophorectomy | |||||||||
| <40 years | 8 | 0.90 | 0.43 1.91 | 71 | 1.69 | 1.28 2.23 | 62 | 1.49 | 1.09 2.02 |
| 40–44 years | 10 | 1.22 | 0.62 2.42 | 43 | 1.29 | 0.92 1.80 | 27 | 1.06 | 0.69 1.60 |
| 45–49 years | 15 | 1.66 | 0.93 2.97 | 35 | 1.04 | 0.72 1.50 | 23 | 1.11 | 0.71 1.73 |
| 50+ years | 11 | 1.76 | 0.92 3.39 | 21 | 1.02 | 0.65 1.60 | 13 | 1.35 | 0.76 2.40 |
| p-value for trend† | 0.10 | <0.01 | 0.35 | ||||||
*
Relative risks (RR) and 95% confidence intervals (CI) from Cox models adjusted for age at entry into cohort, race/ethnicity, education, body mass index, emphysema, smoking status and dose, and, as appropriate, age at menarche, age at natural menopause or age at bilateral oophorectomy.
†
Trends were calculated within menopause subgroups, using the youngest age as the referent, despite the use of a different referent group for the calculation of the RRs.