Table 2.
Selected characteristics (percent) of the study population by race and univariate associations (hazard ratio, 95% confidence interval) with risk of development of metastasis at least seven months after first diagnosis among patients with stages I-III breast cancer, 1992−1999.
| White (n=32,387) | African American (n=2,101) | Other race (n=1,320) | Unadjusted association with development of metastases | |
|---|---|---|---|---|
| Patient factors | ||||
| Age group* | ||||
| 66−69 | 20.9 | 23.9 | 30.2 | 1.00 |
| 70−74 | 28.4 | 29.5 | 33.6 | 0.87 (0.79−0.96) |
| 75−79 | 23.9 | 24.1 | 21.2 | 0.79 (0.71−0.88) |
| 80−84 | 15.9 | 13.2 | 10.2 | 0.69 (0.61−0.78) |
| 85+ | 10.9 | 9.3 | 4.8 | 0.51 (0.44−0.59) |
| Comorbidity* | ||||
| None | 53.9 | 39.0 | 54.4 | 1.00 |
| One | 27.0 | 27.6 | 25.8 | 1.07 (0.98−1.16) |
| Two or more | 17.7 | 31.3 | 17.1 | 1.00 (0.91−1.10) |
| No claims | 1.4 | 2.1 | 2.7 | 0.45 (0.29−0.68) |
| Tumor factors | ||||
| TNM stage* | ||||
| I | 57.9 | 46.5 | 60.3 | 1.00 |
| IIA | 25.2 | 26.4 | 23.4 | 1.85 (1.69−2.02) |
| IIB | 10.0 | 15.5 | 9.9 | 3.03 (2.73−3.36) |
| II (unknown) | 0.8 | 0.8 | 0.4 | 4.13 (3.04−5.61) |
| IIIA | 2.9 | 4.9 | 2.5 | 4.35 (3.72−5.09) |
| IIIB | 3.3 | 6.0 | 3.5 | 3.63 (3.14−4.22) |
| Morphologic grade* | ||||
| Well differentiated (I) | 16.7 | 11.6 | 16.4 | 1.00 |
| Moderately differentiated (II) | 37.0 | 30.3 | 40.2 | 1.97 (1.71−2.27) |
| Poorly differentiated (III) | 24.6 | 30.0 | 24.1 | 3.82 (3.32−4.39) |
| Undifferentiated (IV) | 2.1 | 1.4 | 1.8 | 4.01 (3.12−5.16) |
| Unknown | 19.6 | 26.7 | 17.5 | 3.92 (3.38−4.54) |
| Estrogen receptor* | ||||
| Positive | 68.2 | 54.2 | 69.0 | 1.00 |
| Negative | 12.6 | 18.5 | 15.2 | 1.87 (1.71−2.06) |
| Unknown | 19.3 | 27.4 | 15.8 | 1.23 (1.12−1.35) |
| Progesterone receptor* | ||||
| Positive | 55.9 | 44.4 | 58.0 | 1.00 |
| Negative | 22.5 | 26.3 | 25.2 | 1.57 (1.44−1.70) |
| Unknown | 21.6 | 29.4 | 16.9 | 1.25 (1.15−1.37) |
| Type of treatment | ||||
| Surgery* | ||||
| Breast conserving | 47.7 | 47.0 | 42.7 | 1.00 |
| Mastectomy | 51.6 | 51.2 | 57.0 | 2.04 (1.90−2.20) |
| None | 0.6 | 1.7 | 0.1 | 1.66 (1.15−2.39) |
| Unknown | 0.1 | 0.1 | 0.2 | 2.03 (0.74−5.61) |
| Radiotherapy* | ||||
| No | 36.9 | 33.8 | 38.4 | 1.00 |
| Yes | 61.8 | 63.5 | 59.7 | 0.80 (0.74−0.86) |
| Unknown | 1.3 | 2.7 | 1.9 | 1.07 (0.81−1.40) |
| Lack of access to primary care | ||||
| No | 87.5 | 83.1 | 91.3 | 1.00 |
| Yes* | 12.6 | 16.9 | 8.8 | 0.97 (0.86−1.08) |
| Census-tract level | Mean (s.d.) | Mean (s.d.) | Mean (s.d.) | |
| Poverty rate* | 9.8 (9.0) | 28.2 (16.1) | 12.6 (11.5) | 1.10 (1.06−1.08)** |
| Percent African American* | 5.1 (12.0) | 65.4 (31.4) | 7.0 (14.4) | 1.06 (1.04−1.08)** |
*
p<0.01 for differences by race
**
per 10% increase
s.d.: standard deviation