Table 2.
Age-adjusted and multivariable-adjusted risk of breast cancer-specific mortality associated with race and ethnicity by breast quadrants (n=454,154)
| Deaths from breast cancer |
Person-years | Age-adjusted HR (95%CI) |
Multivariable-adjusted HR (95%CI)a |
|
|---|---|---|---|---|
| White | 34,175 | 36,050,634 | Reference | Reference |
| Black | 7,298 | 4,170,530 | 1.81 (1.76–1.86)** | 1.41 (1.37–1.44)** |
| Asian/PI | 3,075 | 3,714,444 | 0.86 (0.83–0.90)** | 0.82 (0.79–0.85)** |
| Hispanic | 4,756 | 3,966,662 | 1.23 (1.19–1.27)** | 1.05 (1.02–1.09)** |
| Breast quadrants | ||||
| Nipple/central portion of breast | ||||
| White | 3,810 | 3,154,746 | Reference | Reference |
| Black | 626 | 321,451 | 1.59 (1.46–1.73)** | 1.33 (1.22–1.44)** |
| Asian/PI | 423 | 387,036 | 0.91 (0.82–1.00) | 0.82 (0.74–0.91)** |
| Hispanic | 511 | 359,686 | 1.15 (1.05–1.27)** | 0.97 (0.88–1.06) |
| Upper-inner quadrant | ||||
| White | 5,031 | 5,758,358 | Reference | Reference |
| Black | 1,204 | 687,462 | 1.96 (1.84–2.09)** | 1.45 (1.36–1.55)** |
| Asian/PI | 522 | 700,756 | 0.84 (0.77–0.92)** | 0.79 (0.72–0.87)** |
| Hispanic | 775 | 680,719 | 1.27 (1.18–1.37)** | 1.09 (1.01–1.18)* |
| Lower-inner quadrant | ||||
| White | 2,893 | 2,957,899 | Reference | Reference |
| Black | 680 | 401,115 | 1.69 (1.55–1.83)** | 1.34 (1.23–1.46)** |
| Asian/PI | 241 | 299,078 | 0.82 (0.71–0.93)** | 0.80 (0.70–0.91)** |
| Hispanic | 369 | 309,539 | 1.19 (1.07–1.32)** | 1.03 (0.92–1.15) |
| Upper-outer quadrant | ||||
| White | 18,290 | 20,081,992 | Reference | Reference |
| Black | 3,935 | 2,261,009 | 1.86 (1.80–1.93)** | 1.44 (1.39–1.50)** |
| Asian/PI | 1,553 | 1,918,629 | 0.88 (0.84–0.93)** | 0.84 (0.80–0.89)** |
| Hispanic | 2,535 | 2,169,691 | 1.24 (1.19–1.29)** | 1.06 (1.02–1.11)** |
| Lower-outer quadrant | ||||
| White | 3,775 | 3,701,406 | Reference | Reference |
| Black | 739 | 443,261 | 1.62 (1.50–1.76)** | 1.32 (1.22–1.43)** |
| Asian/PI | 310 | 381,388 | 0.79 (0.71–0.89)** | 0.77 (0.69–0.87)** |
| Hispanic | 526 | 413,895 | 1.23 (1.12–1.35)** | 1.05 (0.96–1.16) |
| Axillary tail of breast | ||||
| White | 376 | 396,233 | Reference | Reference |
| Black | 114 | 56,232 | 2.14 (1.73–2.65)** | 1.44 (1.15–1.80)** |
| Asian/PI | 26 | 27,557 | 1.03 (0.69–1.54) | 0.90 (0.61–1.35) |
| Hispanic | 40 | 33,132 | 1.28 (0.92–1.77) | 0.97 (0.69–1.35) |
| Pinteractionb =0.0007 | Pinteractionb =0.51 | |||
CI Confidence interval, HR Hazard ratio, PI Pacific Islander
Statistical significance difference at P value ≤0.05
Statistical significance difference at P value ≤0.01
Hazard ratios were adjusted for age (20–39, 40–49, 50–59, 60–69, or 70–79 years) and year of the diagnosis (1990–1994, 1995–1999, 2000–2004, or 2005–2009, 2010–2014), histopathological features including tumor size (≤2 cm, 2–5 cm, >5 cm, or unknown), grade (well differentiated, moderately differentiated, poorly differentiated and undifferentiated, or unknown), and histological type (IDC,ILC or other histology), laterality of the tumor (right, or left), lymph node status (negative, positive, or unknown), estrogen receptor (ER) status (negative, positive, or unknown), progesterone receptor (PR) status (negative, positive, or unknown), and treatments including surgery (no surgical treatment, breast-conserving surgery(BCS) alone, mastectomy, or unknown), radiation (no/unknown, yes), and chemotherapy (no/unknown, yes)
In age-adjusted Cox regression model, the P value in the interaction effect (quadrant*race) is statistically significant (Pinteraction =0.0007). In adjusted Cox regression model, the P value in the interaction effect (quadrant*race) is statistically non-significant (Pinteraction =0.51)