Table 2 Results of unadjusted and adjusted Cox proportional hazards models for discontinuation of initial or any endocrine therapy, by specified clinical and demographic characteristics
From: Early discontinuation of endocrine therapy for breast cancer: who is at risk in clinical practice?
Clinical and demographic characteristics | N (%) | Initial endocrine therapy | Any endocrine therapy | ||
|---|---|---|---|---|---|
Unadjusted hazard ratio (95% CI) | Adjusted hazard ratio (95% CI) | Unadjusted hazard ratio (95% CI) | Adjusted hazard ratio (95% CI) | ||
Initial therapy: | Â | Â | Â | Â | Â |
Tamoxifen | 917 (59.9%) | 1.00 | 1.00 | 1.00 | 1.00 |
Anastrozole | 518 (33.8%) | 0.53 (0.46–0.61) | 0.57 (0.48–0.67) | 0.64 (0.54–0.76) | 0.90 (0.74–1.09) |
Letrozole | 96 (6.3%) | 0.60 (0.45–0.80) | 0.65 (0.49–0.87) | 0.75 (0.53–1.07) | 1.04 (0.72–1.50) |
Year of diagnosis: | Â | Â | Â | Â | Â |
≥2004 | 1297 (84.7%) | 1.00 | 1.00 | 1.00 | 1.00 |
<2004 | 234 (15.3%) | 1.77 (1.52–2.06) | 0.89 (0.63–1.25) | 2.26 (2.16–3.04) | 1.56 (1.01–2.40) |
Age: | Â | Â | Â | Â | Â |
<55Â years | 454 (29.7%) | 1.00 | 1.00 | 1.00 | 1.00 |
55–74 years | 878 (57.3%) | 0.93 (0.82–1.07) | 1.03 (0.88–1.20) | 1.08 (0.91–1.28) | 1.07 (0.88–1.29) |
≥75 years | 199 (13.0%) | 0.76 (0.62–0.94) | 0.79 (0.62–1.01) | 1.22 (0.96–1.55) | 1.31 (0.98–1.75) |
Tumour size: | Â | Â | Â | Â | Â |
>2Â cm | 533 (34.8%) | 1.00 | 1.00 | 1.00 | 1.00 |
<1–2 cm | 528 (34.5%) | 1.02 (0.88–1.19) | 0.94 (0.80–1.11) | 1.09 (0.90–1.32) | 0.90 (0.73–1.11) |
≤1 cm | 176 (11.5%) | 1.01 (0.82–1.25) | 0.84 (0.67–1.06) | 1.47 (1.15–1.90) | 1.13 (0.86–1.48) |
Missing | 294 (19.2%) | 1.75 (1.49–2.06) | 1.43 (1.03–2.00) | 2.52 (2.07–3.07) | 1.25 (0.82–1.91) |
Stage: | Â | Â | Â | Â | Â |
Node-positive | 608 (39.7%) | 1.00 | 1.00 | 1.00 | 1.00 |
Node-negative | 865 (56.5%) | 1.07 (0.94–1.21) | 0.96 (0.84–1.10) | 1.37 (1.16–1.60) | 1.15 (0.97–1.36) |
Missing | 58 (3.8%) | 1.16 (0.85–1.60) | 0.89 (0.63–1.26) | 1.28 (0.85–1.94) | 0.73 (0.47–1.14) |
No chemotherapy | 1145 (74.7%) | 1.26 (1.09–1.46) | 1.05 (0.87–1.26) | 2.12 (1.72–2.62) | 1.42 (1.11–1.83) |
No mastectomy | 1103 (72.0%) | 1.21 (1.06–1.39) | 1.06 (0.91–1.23) | 1.77 (1.47–2.13) | 1.45 (1.18–1.77) |
No medical oncologista | 922 (60.2%) | 1.16 (1.02–1.32) | 1.05 (0.90–1.23) | 1.84 (1.55–2.17) | 1.20 (0.98–1.48) |
Pre-existing comorbidities: | Â | Â | Â | Â | Â |
Anxiety | 111 (7.3%) | 1.00 (0.78–1.27) | 1.00 (0.78–1.30) | 0.99 (0.74–1.33) | 1.09 (0.79–1.50) |
Depression | 271 (17.7%) | 1.00 (0.85–1.18) | 0.97 (0.81–1.16) | 1.11 (0.91–1.35) | 1.11 (0.91–1.36) |
Hot flashes | 14 (0.9%) | 0.80 (0.40–1.60) | 0.93 (0.46–1.90) | 0.88 (0.39–1.96) | 0.86 (0.38–1.95) |
Musculoskeletal pain | 368 (24.0%) | 1.10 (0.96–1.27) | 1.25 (1.06–1.48) | 1.06 (0.89–1.27) | 0.95 (0.77–1.17) |
Osteoporosis | 86 (5.6%) | 0.81 (0.61–1.07) | 0.77 (0.57–1.04) | 0.91 (0.65–1.28) | 0.84 (0.59–1.21) |
Vaginal atrophy | 43 (2.8%) | 1.08 (0.74–1.57) | 1.27 (0.87–1.87) | 1.05 (0.65–1.67) | 1.06 (0.66–1.72) |
Newly-treated comorbidities: | Â | Â | Â | Â | |
Anxiety | 78 (5.1%) | 1.55 (1.20–1.99) | 1.45 (1.11–1.90) | 1.46 (1.08–1.97) | 1.09 (0.79–1.50) |
Depression | 271 (17.7%) | 1.19 (1.02–1.38) | 1.10 (0.93–1.30) | 1.09 (0.90–1.31) | 1.11 (0.91–1.37) |
Hot flashes | 28 (1.8%) | 1.56 (1.03–2.36) | 1.16 (0.76–1.79) | 2.33 (1.51–3.60) | 2.07 (1.32–3.27) |
Musculoskeletal pain | 328 (21.4%) | 1.14 (0.99–1.32) | 1.15 (0.98–1.35) | 1.03 (0.86–1.23) | 0.90 (0.73–1.09) |
Osteoporosis | 175 (11.4%) | 0.89 (0.74–1.08) | 0.93 (0.76–1.14) | 0.94 (0.74–1.18) | 0.88 (0.69–1.12) |
Vaginal atrophy | 60 (3.9%) | 1.56 (1.18–2.06) | 1.31 (0.98–1.75) | 1.56 (1.13–2.16) | 1.33 (0.95–1.88) |
Location: | Â | Â | Â | Â | Â |
Major city | 690 (45.1%) | 1.00 | 1.00 | 1.00 | 1.00 |
Regional | 544 (35.5%) | 1.05 (0.92–1.21) | 1.08 (0.94–1.24) | 1.12 (0.95–1.32) | 1.10 (0.93–1.31) |
Remote | 297 (19.4%) | 0.96 (0.81–1.13) | 0.94 (0.79–1.12) | 0.97 (0.79–1.19) | 0.93 (0.75–1.15) |
Household income: | Â | Â | Â | Â | Â |
≥$70,000 | 272 (17.8%) | 1.00 | 1.00 | 1.00 | 1.00 |
$30,000-$69,999 | 369 (24.1%) | 0.95 (0.79–1.14) | 0.94 (0.77–1.14) | 1.04 (0.82–1.31) | 1.02 (0.79–1.30) |
<$30,000 | 477 (31.2%) | 0.93 (0.78–1.11) | 0.95 (0.76–1.17) | 1.13 (0.91–1.41) | 1.09 (0.83–1.42) |
Refused | 413 (27.0%) | 0.80 (0.67–0.96) | 0.82 (0.67–1.01) | 0.96 (0.77–1.21) | 0.90 (0.69–1.17) |
Education: | Â | Â | Â | Â | Â |
Undergraduate degree | 330 (21.5%) | 1.00 | 1.00 | 1.00 | 1.00 |
Certificate or diploma | 395 (25.8%) | 0.92 (0.77–1.09) | 0.86 (0.72–1.03) | 1.01 (0.82–1.25) | 0.94 (0.75–1.17) |
High school or less | 777 (50.7%) | 0.87 (0.75–1.02) | 0.88 (0.74–1.04) | 0.95 (0.79–1.15) | 0.89 (0.72–1.10) |
Missing | 30 (2.0%) | 0.84 (0.53–1.34) | 0.85 (0.52–1.38) | 1.03 (0.59–1.82) | 0.90 (0.50–1.63) |
Marital status: | Â | Â | Â | Â | Â |
Partner or spouse | 1084 (70.8%) | 1.00 | 1.00 | 1.00 | 1.00 |
Single | 79 (5.2%) | 1.08 (0.83–1.41) | 1.06 (0.80–1.40) | 1.12 (0.81–1.55) | 1.04 (0.74–1.46) |
Separated or widowed | 369 (24.1%) | 0.93 (0.80–1.07) | 0.95 (0.81–1.11) | 1.00 (0.84–1.19) | 0.87 (0.72–1.06) |
Birth country: | Â | Â | Â | Â | Â |
Australia | 1143 (74.7%) | 1.00 | 1.00 | 1.00 | 1.00 |
NZ, UKb | 188 (12.3%) | 1.14 (0.95–1.36) | 1.19 (0.99–1.43) | 1.42 (1.14–1.76) | 1.56 (1.16–2.10) |
Other | 200 (13.1%) | 0.94 (0.78–1.13) | 0.90 (0.75–1.09) | 0.93 (0.74–1.17) | 1.04 (0.83–1.32) |