Table 2 Incidence rates (IRs) and hazard ratios and associated 95% confidence intervals (95%CIs) of hypothyroidism in the cohort of women diagnosed with non-metastatic breast cancer between 1996 and 2009, who were registered in the Danish Breast Cancer Group clinical database, stratified by the receipt of radiation therapy—to the chest wall only (RTc) or with the addition of the lymph nodes (RTn)—and chemotherapy
From: Incidence of hypothyroidism after treatment for breast cancer—a Danish matched cohort study
Breast cancer survivors | Hazard ratio | ||||||
|---|---|---|---|---|---|---|---|
Treatment modalities | Median age (years) | Cases of hypothyroidism | Numbers | Person years | IR pr. 1000 PY (95% CI) | Crude (95% CI) | Adjusted1 (95% CI) |
RT−/CT− | 66.8 | 728 | 20,754 | 181,597 | 4.01 (3.72–4.31) | Reference group | |
RT−/CT+ | 50.1 | 160 | 4042 | 40,329 | 3.97 (3.38–4.63) | 0.99 (0.83–1.17) | 1.10 (0.91–1.32) |
RTc/CT− | 62.1 | 245 | 6615 | 55,188 | 4.44 (3.90–5.03) | 1.12 (0.96–1.29) | 1.15 (0.99–1.34) |
RTc/CT+ | 51.8 | 82 | 2252 | 19,127 | 4.29 (3.41–5.32) | 1.08 (0.86–1.36) | 1.19 (0.94–1.51) |
RTn/CT− | 62.5 | 254 | 6065 | 48,237 | 5.27 (4.64–5.95) | 1.32 (1.14–1.53) | 1.36 (1.17–1.58) |
RTn/CT+ | 50.1 | 243 | 4846 | 39,922 | 6.09 (5.35–6.90) | 1.53 (1.32–1.77) | 1.71 (1.45–2.01) |