TABLE 2.
Univariate and multivariate analysis of overall survival (OS) and breast cancer‐specific survival (BCSS) in all patients
| Covariate | OS | BCSS | ||||||
|---|---|---|---|---|---|---|---|---|
| Univariate analysis | Multivariate analysis | Univariate analysis | Multivariate analysis | |||||
| 5‐year OS (95% CI) (%) | P | HR (95% CI) | P | 5‐year BCSS (95% CI) (%) | P | HR (95% CI) | P | |
| Surgery type | <0.001 | <0.001 | ||||||
| BCT | 94.7 (94.4–94.9) | 1.0 [reference] | 97.2 (97.1–97.4) | 1.0 [reference] | ||||
| Mastectomy | 87.6 (87.0–88.1) | 1.78 (1.59–1.98) | <0.001 | 94.3 (93.9–94.7) | 1.81 (1.58–2.08) | <0.001 | ||
| Age (years) | <0.001 | <0.001 | ||||||
| ≤50 | 95.5 (95.1–95.8) | 1.0 [reference] | 99.1 (98.9–99.3) | 1.0 [reference] | ||||
| >50 | 92.3 (92.1–92.6) | 1.90 (1.75–2.07) | <0.001 | 95.9 (95.7–96.0) | 1.24 (1.12–1.37) | <0.001 | ||
| T stage | <0.001 | <0.001 | ||||||
| T1 | 94.8 (94.6–95.1) | 1.0 [reference] | 96.9 (96.7–97.0) | 1.0 [reference] | ||||
| T2 | 88.0 (87.5–88.5) | 1.82 (1.71–1.94) | <0.001 | 95.7 (95.4–96.0) | 2.34 (2.13–2.57) | <0.001 | ||
| N stage | <0.001 | |||||||
| N0 | 94.0 (93.8–94.3) | 1.0 [reference] | 96.6 (96.4–96.7) | 0.580 | 1.0 [reference] | |||
| N1 | 89.2 (88.7–89.8) | 1.59 (1.49–1.70) | <0.001 | 96.5 (96.2–96.9) | 1.99 (1.81–2.19) | <0.001 | ||
| Race | <0.001 | <0.001 | ||||||
| White | 93.1 (92.9–93.3) | 1.0 [reference] | 96.4 (96.2–96.6) | 1.0 [reference] | ||||
| Black | 89.6 (88.8–90.4) | 1.23 (1.14–1.33) | <0.001 | 95.9 (95.4–96.4) | 1.28 (1.15–1.42) | <0.001 | ||
| Other | 95.4 (94.9–96.0) | 0.59 (0.53–0.66) | <0.001 | 98.0 (97.7–98.4) | 0.61 (0.52–0.71) | <0.001 | ||
| Unknown | 99.7 (99.0–100.0) | 0.09 (0.02–0.35) | <0.001 | ‐ | 0.09 (0.01–0.68) | <0.001 | ||
| Tumor subtype | <0.001 | 0.140 | ||||||
| HR−/HER2+ (HER2‐enriched) | 90.0 (88.9–91.4) | 1.0 [reference] | 96.6 (95.8–97.3) | 1.0 [reference] | ||||
| HR+/HER2− (Luminal A) | 94.2 (94.0–94.4) | 0.79 (0.69–0.90) | 0.206 | 96.6 (96.4–96.7) | 0.55 (0.46–0.66) | <0.001 | ||
| HR+/HER2+ (Luminal B) | 94.0 (93.3–94.6) | 0.73 (0.62–0.85) | <0.001 | 97.0 (96.5–97.4) | 0.50 (0.40–0.62) | <0.001 | ||
| HR−/HER2− (Triple‐negative) | 85.3 (84.4–86.1) | 1.63 (1.43–1.86) | <0.001 | 96.2 (95.7–96.6) | 1.92 (1.62–2.27) | <0.001 | ||
| Chemotherapy | <0.001 | <0.001 | ||||||
| No/unknown | 93.7 (93.4–93.9) | 1.59 (1.49–1.71) | <0.001 | 95.7 (95.5–95.9) | 0.79 (0.70–0.88) | <0.001 | ||
| Yes | 91.9 (91.6–92.3) | 1.0 [reference] | 97.9 (97.7–98.1) | 1.0 [reference] | ||||
| Nuclear grade | <0.001 | 0.780 | ||||||
| I/II | 94.9 (94.6–95.1) | 1.0 [reference] | 96.6 (96.4–96.8) | |||||
| III/Ⅳ | 89.0 (88.6–89.5) | 1.62 (1.51–1.73) | <0.001 | 96.5 (96.2–96.7) | ||||
| Unknown | 92.2 (90.6–93.7) | 1.39 (1.15–1.68) | <0.001 | 96.4 (95.3–97.3) | ||||
| Radiation therapy | <0.001 | <0.001 | 0.370 | |||||
| No/unknown | 87.8 (87.2–88.5) | 1.12 (1.43–1.86) | 0.052 | 93.9 (93.4–94.3) | 1.07 (0.93–1.23) | |||
| Yes | 94.2 (94.0–94.4) | 1.0 [reference] | 97.2 (97.0–97.3) | 1.0 [reference] | ||||
The univariate analysis was univariate Kaplan–Meier analysis in the OS and Fine‐Gray competing risk analysis in the BCSS. The multivariate analysis was Cox proportional hazards multivariate analysis in the OS and multivariate regression model of competing risk analysis in the BCSS.
Abbreviation: BCT, breast‐conserving therapy.