Table 4.
Associations Between Selected Reproductive and Menopausal Risk Factors and Lung Cancer by Smoking Status Among 185,017 Women, NIH-AARP Diet and Health Study, 1995–2006
| Characteristic | # Lung Cancers (n=276) | Never smokers
|
# Lung Cancers (n=1,509) | Former smokers
|
# Lung Cancers (n=1,727) | Current smokers
|
|||
|---|---|---|---|---|---|---|---|---|---|
| RR* | 95% CI | RR* | 95% CI | RR* | 95% CI | ||||
| Age at menarche (years) | |||||||||
| <11 | 23 | 1.00 | (referent) | 99 | 1.00 | (referent) | 128 | 1.00 | (referent) |
| 11–12 | 121 | 0.76 | 0.48 1.19 | 639 | 0.94 | 0.76 1.17 | 731 | 0.92 | 0.76 1.11 |
| 13–14 | 109 | 0.66 | 0.42 1.04 | 620 | 0.89 | 0.72 1.10 | 694 | 0.87 | 0.72 1.05 |
| 15+ | 21 | 0.55 | 0.30 1.00 | 143 | 0.91 | 0.70 1.18 | 167 | 0.84 | 0.67 1.06 |
| Missing | 2 | 0.95 | 0.21 4.29 | 8 | 1.15 | 0.55 2.42 | 7 | 0.95 | 0.44 2.09 |
| p-value for trend | 0.03 | 0.26 | 0.08 | ||||||
| Age at first live birth among parous women (years) | |||||||||
| <20 | 38 | 1.00 | (referent) | 295 | 1.00 | (referent) | 432 | 1.00 | (referent) |
| 20–24 | 126 | 0.98 | 0.74 1.30 | 677 | 0.99 | 0.88 1.12 | 762 | 0.97 | 0.87 1.08 |
| 25–29 | 53 | 0.90 | 0.63 1.28 | 266 | 1.00 | 0.86 1.17 | 227 | 0.87 | 0.74 1.01 |
| 30+ | 10 | 0.51 | 0.26 0.99 | 69 | 0.83 | 0.64 1.07 | 75 | 0.96 | 0.75 1.22 |
| Missing | 2 | 0.49 | 0.12 2.08 | 20 | 1.25 | 0.78 2.00 | 19 | 1.02 | 0.64 1.63 |
| p-value for trend | 0.22 | 0.18 | 0.04 | ||||||
| Type of and age at menopause | |||||||||
| Natural menopause | |||||||||
| <45 years | 17 | 1.01 | 0.60 1.72 | 143 | 1.37 | 1.13 1.67 | 212 | 1.29 | 1.09 1.52 |
| 45–49 years | 34 | 0.87 | 0.58 1.30 | 270 | 1.20 | 1.02 1.40 | 337 | 1.12 | 0.96 1.29 |
| 50–54 years | 78 | 1.00 | (referent) | 362 | 1.00 | (referent) | 377 | 1.00 | (referent) |
| 55+ years | 23 | 1.11 | 0.70 1.77 | 76 | 0.89 | 0.69 1.14 | 63 | 1.00 | 0.77 1.31 |
| p-value for trend† | 0.56 | <0.0001 | <0.01 | ||||||
| Surgical menopause, bilateral oophorectomy | |||||||||
| <40 years | 14 | 0.94 | 0.53 1.67 | 146 | 1.64 | 1.35 2.00 | 157 | 1.18 | 0.98 1.42 |
| 40–44 years | 13 | 0.96 | 0.53 1.73 | 95 | 1.36 | 1.08 1.70 | 90 | 1.09 | 0.86 1.37 |
| 45–49 years | 19 | 1.30 | 0.79 2.15 | 71 | 1.04 | 0.81 1.34 | 70 | 1.05 | 0.81 1.35 |
| 50+ years | 14 | 1.39 | 0.79 2.46 | 42 | 1.02 | 0.74 1.40 | 29 | 0.92 | 0.63 1.35 |
| p-value for trend† | 0.21 | <0.001 | 0.18 | ||||||
*
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, age at menarche, and type and age at menopause.
†
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.