Supplementary Table 4.
Cox regression models for cancer-specific survival in patients with extraskeletal osteosarcoma in the unmatched cohort.
| Characteristic | Unadjusted* (Unmatched cohort) | Model 1** (Unmatched cohort) | Model 2*** (Unmatched cohort) | ||||
|---|---|---|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | HR (95% CI) | P value | ||
| Chemotherapy | No | Reference | NA | Reference | NA | Reference | NA |
| Yes | 0.887 (0.637–1.236) | 0.479 | 0.765 (0.533–1.099) | 0.147 | 0.727 (0.503–1.049) | 0.088 | |
| Age (year) | <60 | Reference | NA | Reference | NA | Reference | NA |
| ≥60 | 1.547 (1.107–2.163) | 0.011 | 1.672 (1.149–2.432) | 0.007 | 1.680 (1.123–2.513) | 0.012 | |
| Gender | Male | Reference | NA | Reference | NA | ||
| Female | 0.933 (0.670–1.299) | 0.681 | 0.922 (0.619–1.375) | 0.692 | |||
| Race | White | Reference | NA | Reference | NA | ||
| Black | 0.944 (0.567–1.571) | 0.826 | 1.219 (0.702–2.116) | 0.482 | |||
| Other | 0.650 (0.303–1.395) | 0.269 | 0.825 (0.358–1.904) | 0.652 | |||
| Insurance type | Insured | Reference | NA | Reference | NA | ||
| Any medicaid | 1.201 (0.606–2.381) | 0.600 | 0.940 (0.427–2.070) | 0.878 | |||
| Unknown | 0.853 (0.593–1.228) | 0.392 | 1.529 (0.697–3.357) | 0.290 | |||
| Marital status | Single | Reference | NA | Reference | NA | Reference | NA |
| Widowed/divorced | 1.864 (1.074–3.236) | 0.027 | 1.573 (0.866–2.856) | 0.137 | 1.682 (0.910–3.109) | 0.097 | |
| Married | 1.525 (0.924–2.517) | 0.099 | 1.440 (0.835–2.482) | 0.190 | 1.410 (0.797–2.495) | 0.238 | |
| Unknown | 1.717 (0.584–5.053) | 0.326 | 2.123 (0.703–6.412) | 0.182 | 1.739 (0.541–5.591) | 0.353 | |
| Year of diagnosis | 1976 to 1985 | Reference | NA | Reference | NA | ||
| 1986 to 1995 | 1.269 (0.578–2.787) | 0.553 | 1.422 (0.610–3.313) | 0.415 | |||
| 1996 to 2005 | 0.950 (0.465–1.942) | 0.888 | 0.849 (0.391–1.843) | 0.680 | |||
| 2006 to 2016 | 1.266 (0.629–2.549) | 0.509 | 1.809 (0.655–4.994) | 0.253 | |||
| Primary site | Extremity | Reference | NA | Reference | NA | Reference | NA |
| Trunk | 1.608 (1.051–2.460) | 0.028 | 1.953 (1.250–3.053) | 0.003 | 2.138 (1.338–3.415) | 0.001 | |
| Visceral | 3.716 (2.416–5.717) | <0.001 | 3.079 (1.914–4.952) | <0.001 | 3.462 (2.069–5.791) | <0.001 | |
| Other | 1.108 (0.628–1.954) | 0.724 | 1.377 (0.731–2.593) | 0.322 | 1.441 (0.748–2.778) | 0.275 | |
| Grade | Grade I/II | Reference | NA | Reference | NA | Reference | NA |
| Grade III/IV | 4.738 (1.502–14.952) | 0.008 | 4.344 (1.346–14.023) | 0.014 | 4.076 (1.250–13.297) | 0.020 | |
| Unknown | 4.923 (1.521–15.936) | 0.008 | 2.779 (0.838–9.220) | 0.095 | 2.850 (0.850–9.558) | 0.090 | |
| Stage | Localized | Reference | NA | Reference | NA | Reference | NA |
| Regional | 1.830 (1.218–2.751) | 0.004 | 1.543 (1.009–2.359) | 0.045 | 1.718 (1.099–2.686) | 0.018 | |
| Distant | 4.142 (2.675–6.413) | <0.001 | 2.717 (1.642–4.495) | <0.001 | 3.255 (1.878–5.644) | <0.001 | |
| Unstaged | 3.274 (1.698–6.315) | <0.001 | 1.673 (0.817–3.423) | 0.159 | 1.957 (0.906–4.227) | 0.088 | |
| Tumor size (mm) | <73 | Reference | NA | Reference | NA | Reference | NA |
| ≥73 | 2.766 (1.947–3.931) | <0.001 | 3.026 (2.066–4.432) | <0.001 | 3.184 (2.153–4.710) | <0.001 | |
| Radiation | Yes | Reference | NA | Reference | NA | ||
| No | 0.977 (0.669–1.428) | 0.906 | 0.575 (0.367–0.901) | 0.016 | |||
| Surgery | Yes | Reference | NA | Reference | NA | Reference | NA |
| No | 2.894 (1.887–4.438) | <0.001 | 2.533 (1.568–4.092) | <0.001 | 2.729 (1.652–4.506) | <0.001 | |
CI – confidence interval; NA – not applicable; HR – hazard ratio; mm – millimeter.
*
Univariable Cox regression analysis in the unmatched cohort.
**
Multivariable Cox regression adjusted for chemotherapy, age, marital status, primary site, grade, stage, tumor size and surgery in the unmatched cohort.
***
Multivariable Cox regression adjusted for all characteristics in the study in the unmatched cohort.