Table 3. Multivariate Cox regression analyses for the association of risk of selected third non-BC (>10 cases, increased SIR overall) with BC treatment.
| All TNBCs | Stomach | Colorectal | Lung | Non-melanoma skin | Endometrial | Ovarian | Kidney | Haematological | Head and neck | |
|---|---|---|---|---|---|---|---|---|---|---|
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | |
| No. of patients | 583 | 25 | 91 | 77 | 80 | 58 | 33 | 20 | 49 | 18 |
| Age at first BC diagnosis (years) | ||||||||||
| <50 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 50–64 | 1.3 (1.0–1.7) | 2.5 (0.45–13.5) | 3.5 (1.3–9.2) | 1.0 (0.58–1.8) | 1.9 (0.82–4.2) | 2.1 (0.82–5.1) | 0.63 (0.29–1.4) | 1.2 (0.32–4.8) | 1.6 (0.66–3.9) | 0.45 (0.14–1.4) |
| 65+ | 1.8 (1.4–2.3) | 8.1 (1.5–43.8) | 6.4 (2.4–17.1) | 0.47 (0.23–0.95) | 4.6 (2.0–10.6) | 3.2 (1.2–8.3) | 0.13 (0.03–0.49) | 1.9 (0.46–8.1) | 2.2 (0.87–5.6) | 0.07 (0.11–0.39) |
| Incidence year first BC | 1.1 (1.0–1.1) | 1.0 (0.91–1.1) | 1.1 (1.0–1.2) | 1.1 (1.0–1.2) | 1.1 (1.1–1.2) | 1.0 (0.93–1.1) | 0.93 (0.84–1.0) | 1.0 (0.88–1.1) | 1.1 (1.01–1.2) | 1.0 (0.91–1.2) |
| First BC | ||||||||||
| Radiotherapy | 1.1 (0.87–1.3) | 1.8 (0.71–5.0) | 0.69 (0.42–1.2) | 0.93 (0.56–1.6) | 1.5 (0.88–2.5) | 0.69 (0.37–1.3) | 1.4 (0.60–3.1) | 1.6 (0.58–4.3) | 1.6 (0.82–3.1) | 2.9 (0.87–9.9) |
| Chemotherapy | 0.63 (0.45–0.87) | 0.32 (0.03–3.2) | 0.40 (0.11–1.5) | 0.49 (0.21–1.2) | 1.4 (0.61–3.3) | 1.1 (0.41–3.2) | 0.24 (0.05–1.1) | 0.28 (0.03–2.4) | 0.82 (0.29–2.3) | 0.13 (0.01–1.2) |
| Endocrine therapy | 1.0 (0.82–1.3) | 1.2 (0.43–3.5) | 0.63 (0.34–1.2) | 1.2 (0.66–2.3) | 0.69 (0.37–1.3) | 1.4 (0.70–2.7) | 1.2 (0.38–3.5) | 1.7 (0.60–5.0) | 0.62 (0.27–1.4) | 2.0 (0.54–7.3) |
| Second BC | ||||||||||
| Radiotherapy | 1.3 (1.1–1.6) | 1.6 (0.63–4.2) | 1.4 (0.8–2.4) | 1.5 (0.89–2.5) | 1.1 (0.68–1.9) | 1.3 (0.69–2.4) | 1.8 (0.82–4.0) | 0.90 (0.33–2.5) | 1.1 (0.56–2.1) | 0.74 (0.26–2.1) |
| Chemotherapy | 0.93 (0.67–1.3) | 2.3 (0.38–14.0) | 0.80 (0.25–2.6) | 0.58 (0.25–1.4) | 0.55 (0.19–1.6) | 0.95 (0.31–2.9) | 0.95 (0.33–2.7) | 2.1 (0.48–8.8) | 0.70 (0.22–2.2) | 0.54 (0.10–2.8) |
| Endocrine therapy | 1.2 (1.0–1.5) | 0.66 (0.22–2.0) | 1.5 (0.87–2.5) | 1.08 (0.61–1.9) | 1.6 (0.94–2.7) | 1.5 (0.81–2.9) | 0.57 (0.20–1.7) | 2.3 (0.86–6.1) | 2.0 (1.1–3.9) | 3.3 (1.1–10.4) |
Abbreviations: BC=breast cancer; CI=confidence interval; HR=hazard ratio; SIR=standardised incidence ratio; TNBC=third non-breast cancer.
Bold entries denote statistical significance.