Table 4.
Univariable and multivariable analyses of RFS in breast cancer patients among different IHC-based subtypes according to the grade of breast cancer in patients with different Ki-67 expression levels.
| All subtypes | Luminal-like | HER2-positive | TNBC | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HR | 95% Cl | P | HR | 95% Cl | P | HR | 95% Cl | P | HR | 95% Cl | P | ||
| Univariable | |||||||||||||
| Ki-67 Low* | |||||||||||||
| Grade | |||||||||||||
| 1, 2 (reference) | |||||||||||||
| 3 | 2.42 | 1.54 to 3.79 | <0.001 | 2.56 | 1.43 to 4.56 | 0.001 | 1.33 | 0.53 to 3.35 | 0.539 | 3.34 | 0.67 to 16.55 | 0.141 | |
| Ki-67 High* | |||||||||||||
| Grade | |||||||||||||
| 1, 2 (reference) | |||||||||||||
| 3 | 1.25 | 0.92 to 1.70 | 0.162 | 1.5 | 0.94 to 2.40 | 0.088 | 0.86 | 0.52 to 1.44 | 0.57 | 1.12 | 0.50 to 2.47 | 0.789 | |
| Multivariable** | |||||||||||||
| Ki-67 Low* | |||||||||||||
| Grade | |||||||||||||
| 1, 2 (reference) | |||||||||||||
| 3 | 1.92 | 1.81 to 3.11 | 0.008 | 2.12 | 1.13 to 3.99 | 0.02 | 1.16 | 0.44 to 3.05 | 0.762 | 3.33 | 0.64 to 17.32 | 0.153 | |
| Ki-67 High* | |||||||||||||
| Grade | |||||||||||||
| 1, 2 (reference) | |||||||||||||
| 3 | 1.02 | 0.74 to 1.42 | 0.891 | 1.49 | 0.92 to 2.40 | 0.104 | 0.67 | 0.39 to 1.14 | 0.136 | 0.75 | 0.32 to 1.8 | 0.525 | |
Abbreviations: RFS, recurrence-free survival; IHC-based, immunohistochemical-based; HER2, human epidermal growth factor receptor 2; TNBC, triple-negative breast cancer; HR, hazard ratio; CI, confidence interval.
*Ki-67 median = 15%, Ki-67 Low <15%, Ki-67 High ≥ 15%.
** Cox proportional hazard models adjusting for tumour stage, lymph stage, lymphatic vessel invasion (LVI) and IHC-based subtype as covariates.