Table 7.
Univariable and multivariable Cox regression analysis of cancer specific survival.
| Univariable analysis | Multivariable analysis | ||||
|---|---|---|---|---|---|
| E/N | HR (95% CI) | P value | HR (95% CI) | P value | |
| Age | |||||
| <40yrs | 245/1381 | 1 | 1 | ||
| <50yrs | 618/4457 | 0.73 (0.64–0.85) | <0.0001 | 0.86 (0.73–1.00) | 0.053 |
| <60yrs | 850/4874 | 0.97 (0.84–1.11) | 0.64 | 0.94 (0.81–1.10) | 0.43 |
| <70yrs | 522/3125 | 0.99 (0.85–1.15) | 0.89 | 0.95 (0.80–1.12) | 0.55 |
| ≥70yrs | 444/1695 | 1.74 (1.49–2.03) | <0.0001 | 1.26 (1.05–1.51) | 0.015 |
| Race | |||||
| Chinese | 2045/12,753 | 1 | 1 | ||
| Indian | 155/816 | 1.28 (1.09–1.50) | 0.0032 | 1.00 (0.83–1.20) | 0.99 |
| Malay | 417/1519 | 1.94 (1.74–2.16) | <0.0001 | 1.28 (1.13–1.46) | 0.0001 |
| Others | 62/444 | 0.95 (0.74–1.22) | 0.69 | 0.91 (0.69–1.20) | 0.50 |
| AJCC Stage | |||||
| 0 | 24/1944 | 1 | 1 | ||
| I | 185/4214 | 3.46 (2.26–5.29) | <0.0001 | 4.03 (2.60–6.24) | <0.0001 |
| II | 639/5272 | 9.83 (6.55–14.77) | <0.0001 | 8.14 (5.30–12.49) | <0.0001 |
| III | 886/2795 | 29.84 (19.91–44.72) | <0.0001 | 25.19 (16.41–38.66) | <0.0001 |
| IV | 945/1307 | 115.26 (76.81–172.97) | <0.0001 | 65.11 (42.03–100.86) | <0.0001 |
| Housing Index | |||||
| HI (high) | 589/4251 | 1 | 1 | ||
| HI (med) | 1884/10,343 | 1.33 (1.21–1.46) | <0.0001 | 1.15 (1.03–1.27) | 0.0099 |
| HI (low) | 206/938 | 1.63 (1.39–1.92) | <0.0001 | 1.14 (0.95–1.37) | 0.17 |
| MediFund | |||||
| Never received | 2078/13,074 | 1 | 1 | ||
| Ever received | 601/2458 | 1.63 (1.49–1.79) | <0.0001 | 0.96 (0.86–1.07) | 0.47 |
| Marital Status | |||||
| Married | 1753/10,440 | 1 | 1 | ||
| Never married | 348/1992 | 1.08 (0.97–1.22) | 0.16 | 1.09 (0.96–1.23) | 0.17 |
| Previously married | 267/1329 | 1.32 (1.16–1.50) | <0.0001 | 0.93 (0.80–1.08) | 0.36 |
| Unknown | 311/1771 | 1.22 (1.08–1.38) | 0.0015 | 1.01 (0.87–1.17) | 0.9 |
| Tumour grade | |||||
| Grade 1–2 | 742/7562 | 1 | 1 | ||
| Grade 3 | 1315/6352 | 2.28 (2.09–2.49) | <0.0001 | 1.52 (1.38–1.69) | <0.0001 |
| Unknown | 622/1618 | 4.93 (4.42–5.50) | <0.0001 | 1.24 (1.08–1.42) | 0.0019 |
| ER status | |||||
| Positive | 1394/10,160 | 1 | 1 | ||
| Negative | 900/3646 | 1.92 (1.76–2.09) | <0.0001 | 1.87 (1.53–2.28) | <0.0001 |
| Unknown | 385/1726 | 1.47 (1.31–1.65) | <0.0001 | 0.88 (0.52–1.50) | 0.64 |
| PR status | |||||
| Positive | 1136/8650 | 1 | 1 | ||
| Negative | 1138/5022 | 1.84 (1.70–2.00) | <0.0001 | 1.40 (1.23–1.60) | <0.0001 |
| Unknown | 405/1860 | 1.53 (1.36–1.72) | <0.0001 | 1.08 (0.64–1.82) | 0.76 |
| HER2 status | |||||
| Negative | 1351/8377 | 1 | 1 | ||
| Positive | 753/3528 | 1.40 (1.28–1.54) | <0.0001 | 0.79 (0.47–1.33) | 0.38 |
| Unknown | 575/3627 | 0.92 (0.83–1.01) | 0.083 | 0.88 (0.52–1.50) | 0.65 |
| Timely surgerya | |||||
| Yes | 1280/12,474 | 1 | |||
| No | 103/259 | 4.40 (3.60–5.39) | <0.0001 | ||
| Not needed | 945/1307 | 13.66 (12.49–14.94) | <0.0001 | ||
| Not assessable | 351/1492 | 2.71 (2.41–3.05) | <0.0001 | ||
| Radiotherapy | |||||
| Yes | 921/7023 | 1 | 1 | ||
| No | 218/749 | 2.48 (2.14–2.87) | <0.0001 | 1.84 (1.55–2.19) | <0.0001 |
| Not needed | 270/4286 | 0.49 (0.43–0.56) | <0.0001 | 0.87 (0.75–1.01) | 0.075 |
| Not assessable | 1270/3474 | 3.90 (3.58–4.25) | <0.0001 | 1.72 (1.50–1.97) | <0.0001 |
| Chemotherapy | |||||
| Yes | 1086/6069 | 1 | 1 | ||
| No | 320/1965 | 0.90 (0.79–1.01) | 0.084 | 0.99 (0.85–1.16) | 0.93 |
| Not needed | 61/2339 | 0.14 (0.11–0.18) | <0.0001 | 0.53 (0.37–0.76) | 0.0005 |
| Not assessable | 1212/5159 | 1.49 (1.37–1.61) | <0.0001 | 1.19 (1.03–1.36) | 0.016 |
| Endocrine therapy | |||||
| Yes | 1188/8563 | 1 | 1 | ||
| No | 91/857 | 0.81 (0.65–1.00) | 0.048 | 1.49 (1.17–1.91) | 0.0014 |
| Not needed | 752/3097 | 1.97 (1.80–2.16) | <0.0001 | 0.80 (0.62–1.02) | 0.077 |
| Not assessable | 648/3015 | 1.70 (1.54–1.87) | <0.0001 | 1.66 (1.42–1.94) | <0.0001 |
| Targeted therapy | |||||
| Yes | 160/1366 | 1 | 1 | ||
| No | 230/756 | 2.24 (1.83–2.73) | <0.0001 | 2.62 (2.11–3.24) | <0.0001 |
| Not needed | 1379/9518 | 1.17 (0.99–1.38) | 0.058 | 1.60 (0.93–2.76) | 0.087 |
| Not assessable | 910/3892 | 1.96 (1.66–2.32) | <0.0001 | 1.82 (1.45–2.28) | <0.0001 |
a
Due to concern of multicollinearity, “Timely surgery” was excluded from multivariable analyses as all Stage IV patients were categorized as not needing (“No”) surgery. All variables analysed in univariable analysis were used as covariates for adjustment in the multivariable analysis.
AJCC: American Joint Committee on Cancer, 7th edition, ER: estrogen receptor, PR: Progesterone receptor, HER2: Human epidermal growth factor receptor 2.