Table 2.
Propensity score-weighted Cox proportional hazards models
| T1 (diagnosis → iIBC ≤ 5) HR (95% CI) | T2 (diagnosis → iIBC > 5) HR (95% CI) | T3 (diagnosis → cIBC) HR (95% CI) | T4 (diagnosis → death) HR (95% CI) | T5 (iIBC ≤ 5 → death) HR (95% CI) | T6 (iIBC > 5 → death) HR (95% CI) | T7 (cIBC → death) HR (95% CI) | ||
|---|---|---|---|---|---|---|---|---|
| Local treatment | BCS+RT | REF | REF | REF | REF | REF | REF | REF |
| Mastectomy | 0.50 (0.39–0.65) | 0.21 (0.16–0.26) | 1.18 (1.07–1.31) | 1.14 (1.08–1.20) | 1.30 (0.74–2.30) | 1.31 (0.68–2.52) | 0.96 (0.75–1.23) | |
| BCS | 3.14 (2.70–3.67) | 1.35 (1.20–1.53) | 1.05 (0.95–1.16) | 1.19 (1.13–1.25) | 1.05 (0.70–1.58) | 0.99 (0.70–1.39) | 1.01 (0.78–1.23) | |
| No local treatment | 4.26 (3.12–5.81) | 1.69 (1.19–2.41) | 1.17 (0.87–1.57) | 1.55 (1.34–1.78) | 3.32 (1.31–8.45) | 1.01 (0.38–2.70) | 1.81 (1.06–3.09) | |
| Year of diagnosis | 1.02 (0.98–1.05) | 0.97 (0.94–1.01) | 1.00 (0.98–1.01) | 1.00 (0.99–1.01) | 1.03 (0.97–1.09) | 0.98 (0.86 –1.12) | 1.02 (0.97–1.07) | |
| Age at DCIS diagnosis | 50–69 | REF | REF | REF | REF | REF | REF | REF |
| 40–49 | 1.86 (1.34–2.57) | 1.37 (1.02–1.83) | 0.76 (0.63–0.92) | 0.31 (0.24–0.39) | 1.29 (0.55–3.07) | 1.20 (0.50–2.85) | 1.23 (0.68–2.23) | |
| 70–74 | 1.01 (0.59–1.74) | 1.20 (0.74–1.95) | 1.40 (1.09–1.80) | 3.23 (2.84–3.68) | 4.97 (2.08–11.88) | 2.44 (0.98–6.05) | 2.08 (1.19–3.64) | |
| 75–79 | 0.95 (0.61–1.46) | 0.97 (0.75–1.25) | 1.02 (0.76–1.37) | 5.96 (5.28–6.72) | 4.46 (2.11–9.44) | 4.25 (2.28–7.90) | 2.96 (1.54–5.68) | |
| ≥ 80 | 1.14 (0.80–1.63) | 0.62 (0.44–0.87) | 1.06 (0.74–1.51) | 10.84 (9.78–12.02) | 6.24 (3.26–11.93) | 6.76 (3.12–14.64) | 5.86 (3.73–9.22) | |
| Grade | 2 | REF | REF | REF | REF | REF | REF | REF |
| 1 | 0.87 (0.58–1.32) | 1.04 (0.74–1.44) | 0.84 (0.69–1.02) | 1.13 (1.02–1.24) | 0.72 (0.29–1.78) | 0.94 (0.41–2.14) | 1.26 (0.82–1.93) | |
| 3 | 1.42 (1.05–1.91) | 1.00 (0.73–1.38) | 0.82 (0.68–1.02) | 1.10 (0.99–1.22) | 1.23 (0.66–2.32) | 1.29 (0.69–2.42) | 0.70 (0.45–1.09) | |
| Race | Caucasian | REF | REF | REF | REF | REF | REF | REF |
| African American | 2.52 (1.83–3.48) | 1.79 (1.25–2.55) | 1.12 (0.89–1.42) | 1.37 (1.21–1.54) | 1.47 (0.71–3.07) | 1.51 (0.68–3.39) | 0.97 (0.58–1.62) | |
| Other | 1.46 (0.84–2.55) | 1.54 (1.00–2.36) | 1.07 (0.82–1.39) | 0.75 (0.64–0.88) | 0.46 (0.15–1.40) | 1.77 (0.64–4.95) | 0.66 (0.26–1.69) | |
| Lesion size | < 2 cm | REF | REF | REF | REF | REF | REF | REF |
| ≥ 2 cm | 1.66 (1.23–2.25) | 1.38 (1.00–2.36) | 1.08 (0.90–1.30) | 1.18 (1.06–1.30) | 1.75 (1.02–3.01) | 1.80 (0.82–3.93) | 1.28 (0.85–1.91) | |
| ER status | Negative | REF | REF | REF | REF | REF | REF | REF |
| Positive | 0.76 (0.53–1.10) | 1.51 (0.98–2.33) | 1.13 (0.87–1.46) | 0.94 (0.83–1.06) | 0.40 (0.19–0.85) | 0.51 (0.29–0.90) | 0.67 (0.36–1.25) |
CI confidence interval, cIBC contralateral invasive breast cancer, DCIS ductal carcinoma in-situ, BCS breast conserving surgery, HR hazard ratio, iIBC ipsilateral invasive breast cancer, IQR inter-quartile range, ER estrogen receptor, REF reference category, RT radiotherapy