Table 3.
Univariable and multivariable Cox regression analysis with all-cause death as the endpoint, including only cases with no missing information for all co-variables in both models
| No. of cases (n=3320) | No. of deaths (n=207) | Univariable HR | P | Multivariable HR | P | |
|---|---|---|---|---|---|---|
| Age (years) | <0.001 | 0.001 | ||||
| <41 | 129 | 5 | 0.40 (0.16, 0.98) | 0.71 (0.20, 2.57) | ||
| 41–50 | 530 | 18 | 0.36 (0.22, 0.59) | 0.70 (0.28, 1.73) | ||
| 51–65 | 1330 | 70 | 0.56 (0.41, 0.75) | 0.52 (0.38, 0.72) | ||
| >65 | 1331 | 114 | 1.00 (reference) | 1.00 (reference) | ||
| Invasive tumour category * | 0.011 | 0.062 | ||||
| T1 | 2452 | 135 | 1.00 (reference) | 1.00 (reference) | ||
| T2–3 | 868 | 72 | 1.45 (1.09, 1.92) | 1.34 (0.98, 1.82) | ||
| Histological subtype | 0.690 | 0.452 | ||||
| Ductal | 2651 | 168 | 1.00 (reference) | 1.00 (reference) | ||
| Lobular | 375 | 19 | 0.82 (0.51, 1.31) | 0.74 (0.45, 1.22) | ||
| Other | 294 | 20 | 1.04 (0.65, 1.65) | 1.07 (0.66, 1.73) | ||
| Tumour multifocality | 0.951 | 0.986 | ||||
| Yes | 258 | 15 | 0.98 (0.58, 1.66) | 1.00 (0.59, 1.71) | ||
| No | 3062 | 192 | 1.00 (reference) | 1.00 (reference) | ||
| Node category | 0.011 | 0.075 | ||||
| Negative | 2536 | 141 | 1.00 (reference) | 1.00 (reference) | ||
| Positive | 784 | 66 | 1.46 (1.09, 1.96) | 1.45 (0.96, 2.19) | ||
| Nottingham histological grade | 0.003 | 0.035 | ||||
| 1 | 634 | 28 | 1.00 (reference) | 1.00 (reference) | ||
| 2 | 1716 | 98 | 1.38 (0.90, 2.10) | 1.36 (0.88, 2.10) | ||
| 3 | 970 | 81 | 1.97 (1.28, 3.03) | 1.94 (1.16, 3.24) | ||
| Tumour surrogate subtype † | <0.001 | 0.696 | ||||
| ER/PR+ HER2− | 2742 | 162 | 1.00 (reference) | 1.00 (reference) | ||
| ER/PR+ HER2+ | 242 | 9 | 0.64 (0.32, 1.24) | 0.76 (0.26, 2.22) | ||
| ER/PR− HER2+ | 87 | 4 | 0.77 (0.28, 2.07) | 0.42 (0.07, 2.44) | ||
| ER/PR− HER2− | 249 | 32 | 2.32 (1.59, 3.39) | 0.98 (0.31, 3.17) | ||
| Chemotherapy | 0.479 | 0.417 | ||||
| Yes | 1400 | 92 | 1.10 (0.84, 1.45) | 0.85 (0.58, 1.25) | ||
| No | 1920 | 115 | 1.00 (reference) | 1.00 (reference) | ||
| Endocrine therapy | <0.001 | 0.183 | ||||
| Yes | 2973 | 169 | 1.00 (reference) | 1.00 (reference) | ||
| No | 347 | 38 | 2.01 (1.41, 2.85) | 2.15 (0.70, 6.66) | ||
| Anti-HER2 therapy | 0.067 | 0.557 | ||||
| Yes | 295 | 11 | 0.57 (0.31, 1.04) | 0.72 (0.23, 2.19) | ||
| No | 3025 | 196 | 1.00 (reference) | 1.00 (reference) | ||
| Type of surgery | 0.508 | 0.289 | ||||
| Standard BCS | 2991 | 185 | 1.00 (reference) | 1.00 (reference) | ||
| Simple OPS | 184 | 13 | 1.39 (0.79, 2.44) | 1.57 (0.89, 2.77) | ||
| Complex OPS | 145 | 9 | 1.10 (0.75, 2.16) | 1.12 (0.57, 2.21) | ||
| Closest peripheral margin (mm) | 0.387 | 0.258 | ||||
| ≥2 | 2865 | 184 | 1.00 (reference) | 1.00 (reference) | ||
| <2 | 455 | 23 | 0.83 (0.53, 1.27) | 1.29 (0.83, 2.01) | ||
| Radiation dose and fractionation | 0.003 | 0.140 | ||||
| Hypofractionation | 1549 | 100 | 1.00 (reference) | 1.00 (reference) | ||
| Standard fractionation | 1165 | 89 | 0.95 (0.72, 1.27) | 0.84 (0.61, 1.16) | ||
| Hypofractionation + boost | 304 | 5 | 0.24 (0.10, 0.60) | 0.25 (0.07, 0.87) | ||
| Standard fractionation + boost | 302 | 13 | 0.52 (0.29, 0.92) | 0.41 (0.14, 1.19) | ||
| Regional node irradiation | 0.043 | 0.492 | ||||
| Yes | 464 | 39 | 1.43 (1.01, 2.03) | 1.20 (0.71, 2.02) | ||
| No | 2856 | 168 | 1.00 (reference) |
Values in parentheses are 95 per cent confidence intervals. Each patient represents one case: bilateral cancers generate one case only, with the analysed laterality selected at random. *Pretreatment cT category for neoadjuvant cases and histopathological tumour size for primary surgery. †Values derived from pretreatment core needle biopsy in neoadjuvant cases and from histopathological assessment of specimen in primary surgery. HR, hazard ratio; ER, oestrogen receptor; PR, progesterone receptor; HER2, human epidermal growth factor receptor 2; BCS, breast-conserving surgery; OPS, oncoplastic breast-conserving surgery.