Table 2.
Multivariable logistic regression for the presence of bone metastases at diagnosis of breast cancer in the SEER cohort
| Patient characteristics | Among entire cohort | Among subset with metastatic disease | ||
|---|---|---|---|---|
| OR (95% CI) | P‐value | OR (95% CI) | P‐value | |
| Age at diagnosis | ||||
| 18‐49 | Reference | Reference | Reference | Reference |
| 50‐64 | 1.109 (1.036‐1.188) | 0.003 | 1.000 (0.899‐1.112) | 0.996 |
| ≥65 | 1.000 (0.931‐1.073) | 0.993 | 0.826 (0.740‐0.922) | 0.001 |
| Sex | ||||
| Female | Reference | Reference | Reference | Reference |
| Male | 1.450 (1.136‐1.850) | 0.003 | 1.207 (0.835‐1.744) | 0.317 |
| Race | ||||
| White | Reference | Reference | Reference | Reference |
| Black | 0.989 (0.915‐1.068) | 0.773 | 0.808 (0.725‐0.901) | <0.001 |
| Hispanic | 0.864 (0.792‐0.942) | 0.001 | 0.893 (0.783‐1.019) | 0.093 |
| Asian | 0.775 (0.699‐0.859) | <0.001 | 0.874 (0.747‐1.021) | 0.090 |
| Othersa | 0.798 (0.564‐1.130) | 0.203 | 0.897 (0.549‐1.466) | 0.666 |
| Histology | ||||
| IDC | Reference | Reference | Reference | Reference |
| ILC | 1.996 (1.840‐2.165) | <0.001 | 1.243 (1.065‐1.451) | 0.006 |
| Othersb | 1.238 (1.157‐1.325) | <0.001 | 0.927 (0.837‐1.026) | 0.143 |
| Grade | ||||
| I | Reference | Reference | Reference | Reference |
| II | 2.449 (2.219‐2.702) | <0.001 | 1.125 (0.928‐1.365) | 0.229 |
| III/IV | 2.872 (2.587‐3.187) | <0.001 | 0.712 (0.587‐0.863) | 0.001 |
| Unknown | 7.576 (6.770‐8.478) | <0.001 | 0.992 (0.813‐1.212) | 0.940 |
| Tumor subtype | ||||
| HR+/HER‐ | Reference | Reference | Reference | Reference |
| HR‐/HER2+ | 0.618 (0.548‐0.698) | <0.001 | 0.390 (0.338‐0.450) | <0.001 |
| HR+/HER2+ | 1.063 (0.981‐1.151) | 0.136 | 0.737 (0.656‐0.828) | <0.001 |
| Triple‐negative | 0.470 (0.426‐0.519) | <0.001 | 0.340 (0.301‐0.384) | <0.001 |
| Unknown | 0.780 (0.624‐0.788) | <0.001 | 0.669 (0.591‐0.756) | <0.001 |
| Extraosseous metastatic sites, No. | ||||
| 0 | Reference | Reference | Reference | Reference |
| 1 | 44.896 (41.868‐48.143) | <0.001 | 0.391 (0.358‐0.426) | <0.001 |
| 2 | 89.690 (78.928‐101.919) | <0.001 | 0.814 (0.709‐0.934) | 0.003 |
| All 3 | 192.634 (130.771‐283.765) | <0.001 | 1.895 (1.286‐2.792) | 0.001 |
| Unknown | 4.906 (4.396‐5.475) | <0.001 | 0.494 (0.423‐0.577) | <0.001 |
| Marital status | ||||
| Married | Reference | Reference | Reference | Reference |
| Unmarriedc | 1.367 (1.296‐1.443) | <0.001 | 1.049 (0.966‐1.139) | 0.258 |
| Unknown | 0.959 (0.852‐1.079) | 0.483 | 0.894 (0.755‐1.060) | 0.197 |
| Insurance | ||||
| Insured | Reference | Reference | Reference | Reference |
| Uninsured | 1.592 (1.387‐1.827) | <0.001 | 1.069 (0.887‐1.289) | 0.483 |
| Unknown | 0.571 (0.476‐0.683) | <0.001 | 0.743 (0.577‐0.955) | 0.021 |
| Residence type | ||||
| Urban | Reference | Reference | Reference | Reference |
| Rural | 0.992 (0.906‐1.086) | 0.863 | 0.908 (0.792‐1.042) | 0.169 |
| Median household income (per $10 000 annual increase) | 0.951 (0.931‐0.972) | <0.001 | 0.977 (0.946‐1.010) | 0.173 |
| High school education (per 10% increase) | 1.066 (1.024‐1.111) | 0.002 | 1.081 (1.016‐1.151) | 0.015 |
CI, confidence interval; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; IDC, infiltrating ductal carcinoma; ILC, infiltrating lobular carcinoma.
Unknown age and unknown race removed from model owing to nonconvergence (n = 1798).
a
Including American Indian/Alaskan native and Pacific Islander.
b
Including other histology of invasive breast cancer except IDC and ILC.
c
Including divorced, separated, single (never married), and widowed.