Table 2.
Univariable and multivariable Cox regression models of PAM50 breast cancer intrinsic subtypes in primary tumors, lymph node metastases, and distant metastases.
| Univariable PFS | Multivariable PFS a | Univariable OS | Multivariable OS a | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | HR (95% CI) | p | n | HR (95% CI) | p | n | HR (95% CI) | p | n | HR (95% CI) | p | |
| PT | 123 | 89 | 123 | 69 | ||||||||
| PAM50 subtype | 0.002 b | 0.007 b | 0.001 b | 0.001 b | ||||||||
| Lum A | 47 | 1.00 | 1.00 | 1.00 | 1.00 | |||||||
| Lum B | 45 | 0.94 (0.61–1.4) | 0.79 | 0.93 (0.54–1.6) | 0.81 | 1.1 (0.66–1.8) | 0.77 | 0.92 (0.48–1.8) | 0.81 | |||
| HER2-E | 15 | 1.1 (0.58–2.0) | 0.82 | 0.88 (0.38–2.0) | 0.77 | 1.0 (0.52–2.1) | 0.92 | 0.77 (0.31–1.9) | 0.57 | |||
| Basal-like | 16 | 2.8 (1.6–5.1) | 0.001 | 3.8 (1.5–9.3) | 0.004 | 3.4 (1.8–6.3) | <0.001 | 4.6 (1.8–11.3) | 0.001 | |||
| LNM | 68 | 55 | 68 | 44 | ||||||||
| PAM50 subtype | 0.05 b | 0.28 b | 0.09 b | 0.17 b | ||||||||
| Lum A | 18 | 1.00 | 1.00 | 1.00 | 1.00 | |||||||
| Lum B | 37 | 1.1 (0.6–1.9) | 0.84 | 0.88 (0.41–1.9) | 0.76 | 0.93 (0.5–1.7) | 0.81 | 1.2 (0.53–2.8) | 0.63 | |||
| HER2-E | 9 | 0.73 (0.3–1.8) | 0.48 | 0.41 (0.13–1.3) | 0.12 | 0.63 (0.23–1.7) | 0.37 | 0.45 (0.13–1.6) | 0.23 | |||
| Basal-like | 4 | 4.2 (1.4–13) | 0.01 | 1.5 (0.37–6.4) | 0.55 | 3.4 (1.1–10.3) | 0.04 | 2.7 (0.64–11.6) | 0.18 | |||
| DM | 74 | 58 | 74 | 42 | ||||||||
| PAM50 subtype | 0.11 b | 0.002 b | 0.91 b | 0.05 b | ||||||||
| Lum A | 7 | 1.00 | 1.00 | 1.00 | 1.00 | |||||||
| Lum B | 41 | 0.60 (0.26–1.4) | 0.22 | 0.26 (0.08–0.80) | 0.02 | 0.77 (0.32–1.9) | 0.56 | 0.46 (0.13–1.6) | 0.22 | |||
| HER2-E | 19 | 1.0 (0.42–2.5) | 0.97 | 0.64 (0.20–2.1) | 0.46 | 0.88 (0.33–2.4) | 0.81 | 1.6 (0.40–6.8) | 0.49 | |||
| Basal-like | 7 | 1.4 (0.46–3.9) | 0.58 | 2.4 (0.54–10.3) | 0.26 | 0.69 (0.21–2.3) | 0.55 | 1.3 (0.24–6.4) | 0.79 | |||
Abbreviations: CI: confidence interval; DM: distant metastasis; ECOG: Eastern Cooperative Oncology Group; HR: hazard ratio; HER2-E: human epidermal growth factor receptor 2 enriched; LNM: lymph node metastasis; MFI: metastasis-free interval; NHG: Nottingham Histological Grade; n: number; OS: overall survival; PT: primary tumor; PFS: progression-free survival. a Adjusted for age at diagnosis of metastatic breast cancer (<65 versus ≥65 years), ECOG performance status (0 versus 1 versus 2), NHG of PT (I versus II versus III), MFI (0 versus >0–3 versus >3 years), number of metastatic sites (<3 versus ≥3), site of metastasis (visceral versus non-visceral), and circulating tumor cell (CTC) status (<5 versus ≥5 CTCs); b 3-degree-of-freedom overall test.