Table 1.
Characteristics of breast cancer cases by paritya
| Parity | All | 0 | 1–2 | 3 | P-valueb |
|---|---|---|---|---|---|
| N | 159 | 24 (15%) | 63 (40%) | 72 (45%) | |
| Age at diagnosis, years | 60.6±8.7 | 56.8±9.2 | 58.9±8.8 | 63.4±7.6 | <0.001 |
| Body mass index, kg/m2 | 24.4±4.3 | 24.1±6.5 | 24.3±3.7 | 24.7±3.9 | 0.69 |
| Hormone replacement therapy use | <0.01 | ||||
| Never | 64 (40%) | 12 (50%) | 34 (54%) | 18 (25%) | |
| Current/past user | 95 (60%) | 12 (50%) | 29 (46%) | 54 (75%) | |
| Menopausal status | <0.001 | ||||
| Premenopausal | 60 (38%) | 14 (58%) | 31 (49%) | 15 (21%) | |
| Postmenopausal | 99 (62%) | 10 (42%) | 32 (51%) | 57 (79%) | |
| Education, years | 14.6±2.4 | 14.7±2.5 | 14.9±2.2 | 14.4±2.5 | 0.34 |
| Family history of breast cancer | 17 (11%) | 3 (13%) | 5 (8%) | 9 (13%) | 0.66 |
| Ethnicity | 0.97 | ||||
| Japanese American | 70 (44%) | 9 (37%) | 29 (46%) | 32 (44%) | |
| Caucasian | 49 (31%) | 8 (33%) | 18 (28%) | 23 (32%) | |
| Native Hawaiian | 21 (13%) | 3 (13%) | 8 (13%) | 10 (14%) | |
| Other | 19 (12%) | 4 (17%) | 8 (13%) | 7 (10%) | |
| Age at first-live birth, years | <0.0001 | ||||
| No children | 24 (15%) | 24 (100%) | -- | -- | |
| < 21 | 21 (13%) | -- | 7 (11%) | 14 (20%) | |
| 21–30 | 103 (65%) | -- | 46 (73%) | 57 (79%) | |
| ≥ 31 | 11 (7%) | -- | 10 (16%) | 1 (1%) | |
| Age at menarche, years | 0.63 | ||||
| < 13 | 86 (54%) | 12 (50%) | 36 (57%) | 38 (53%) | |
| 13–14 | 58 (37%) | 10 (42%) | 19 (30%) | 29 (40%) | |
| > 14 | 15 (9%) | 2 (8%) | 8 (13%) | 5 (7%) |
a
Data are presented as mean±SD or N (%). Of the 159 women, missing marker expression data were recorded for N=1 for PR and PCNA, N=2 for ERα and ERβ; N=3 for Her2/neu; and N=4 for Ki-67.
b
P-values from χ2 test (categorical variables) or Students t-test (continuous variable).