Table 4.
Multivariable Logistic Regression on Risk Factors for Three Types of Breast Cancers among Premenopausal Women (N=1,715), Nigeria, 1998-2011a
| PABC | Non-PABC | |||
|---|---|---|---|---|
|
|
||||
| ≤2 years postpartum |
3-5 years postpartum |
>5 years postpartum or nulliparous |
P for heterogeneity |
|
| Sample Size: Cases | N=152 | N=145 | N=421 | |
| Controls | N=282 | N=188 | N=525 | |
| Odds ratio: Case vs. Control (95% confidence interval) | ||||
| Age at menarche (years ) | ||||
| 10-14 | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) | 0.7 |
| 15-16 | 1.18 (0.67-2.10) | 1.00 (0.55-1.81) | 1.02 (0.71-1.47) | |
| 17-18 | 0.94 (0.45-1.93) | 0.32 (0.12-0.80) | 0.75 (0.48-1.19) | |
| ≥19 | 0.32 (0.09-1.13) | 0.49 (0.13-1.82) | 0.40 (0.16-0.98) | |
| p-value for trend | 0.2 | 0.05 | 0.06 | |
|
| ||||
| Family history of breast cancer | ||||
| No | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) | 0.3 |
| Yes | 3.28 (1.05-10.3) | 1.35 (0.39-4.64) | 1.84 (0.86-2.75) | |
|
| ||||
| Benign breast disease | ||||
| No | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) | 0.6 |
| Yes | 2.30 (0.82-6.41) | 1.73 (0.57-5.27) | 1.49 (0.80-2.77) | |
|
| ||||
| Hormonal contraceptives (%) | ||||
| No | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) | 0.7 |
| Yes | 0.87 (0.49-1.53) | 0.96 (0.53-1.73) | 0.92 (0.65-1.30) | |
|
| ||||
| Alcohol drinking | ||||
| No | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) | 0.3 |
| Yes | 1.14 (0.27-4.84) | 0.96 (0.32-2.89) | 1.76 (0.99-3.13) | |
|
| ||||
| Anthropometry | ||||
| Height (per 5 cm) | 1.07 (0.89-1.28) | 1.32 (1.07-1.62) | 1.11 (0.99-1.26) | 0.9 |
| BMI (per 5 kg/m2) | 0.73 (0.56-0.95) | 0.75 (0.56-1.01) | 0.82 (0.70-0.95) | 0.3 |
PABC, pregnancy-associated breast cancer; BMI, body mass index
a
Model controlled for age in 3-year category, ethnicity, education, parity, age of first live birth, breastfeeding, and number of abortion, in addition to variables listed in the table.