TY - JOUR
T1 - Mortality after contralateral breast cancer in Denmark
AU - Langballe, Rikke
AU - Frederiksen, Kirsten
AU - Jensen, Maj-Britt
AU - Andersson, Michael
AU - Cronin-Fenton, Deirdre
AU - Ejlertsen, Bent
AU - Mellemkjær, Lene
N1 - Publisher Copyright: © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Purpose: How a second breast cancer diagnosis affects survival in comparison with unilateral breast cancer (UBC) is unclear. Prognostic factors for contralateral breast cancer (CBC) are also not well established. We aimed to investigate the survival pattern after CBC with particular focus on time between first and second breast cancer diagnosis and age at CBC diagnosis. Methods: Within the nationwide Danish Breast Cancer Cooperative Group database, we identified 68,466 breast cancer patients diagnosed during 1978–2012. Patients who subsequently developed CBC were identified in a previously established database (N = 3004). Patients were followed for breast cancer-specific death in the Danish Register of Causes of Death until 2015. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard regression models. Cumulative breast cancer mortality from date of CBC was estimated using the Aalen–Johansen method. Results: Compared with UBC patients, the rate of dying from breast cancer was more than twofold higher following a CBC diagnosis, after adjustment for age, period, tumor characteristics, and treatment of the first breast cancer (HR 2.48; 95% CI 2.31–2.66). Short time interval (< 5 years) was associated with higher breast cancer-specific mortality after CBC among patients < 70 years at CBC diagnosis compared with longer time intervals, but not among patients ≥ 70 years at CBC diagnosis. Conclusion: Breast cancer-specific mortality rates were markedly higher after compared with before a CBC diagnosis. We found higher breast cancer-specific mortality after CBC associated with a short interval between diagnoses among patients diagnosed with CBC before age 70 years.
AB - Purpose: How a second breast cancer diagnosis affects survival in comparison with unilateral breast cancer (UBC) is unclear. Prognostic factors for contralateral breast cancer (CBC) are also not well established. We aimed to investigate the survival pattern after CBC with particular focus on time between first and second breast cancer diagnosis and age at CBC diagnosis. Methods: Within the nationwide Danish Breast Cancer Cooperative Group database, we identified 68,466 breast cancer patients diagnosed during 1978–2012. Patients who subsequently developed CBC were identified in a previously established database (N = 3004). Patients were followed for breast cancer-specific death in the Danish Register of Causes of Death until 2015. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard regression models. Cumulative breast cancer mortality from date of CBC was estimated using the Aalen–Johansen method. Results: Compared with UBC patients, the rate of dying from breast cancer was more than twofold higher following a CBC diagnosis, after adjustment for age, period, tumor characteristics, and treatment of the first breast cancer (HR 2.48; 95% CI 2.31–2.66). Short time interval (< 5 years) was associated with higher breast cancer-specific mortality after CBC among patients < 70 years at CBC diagnosis compared with longer time intervals, but not among patients ≥ 70 years at CBC diagnosis. Conclusion: Breast cancer-specific mortality rates were markedly higher after compared with before a CBC diagnosis. We found higher breast cancer-specific mortality after CBC associated with a short interval between diagnoses among patients diagnosed with CBC before age 70 years.
KW - Adult
KW - Age of Onset
KW - Aged
KW - Aged, 80 and over
KW - Breast Neoplasms/epidemiology
KW - Denmark/epidemiology
KW - Female
KW - Humans
KW - Middle Aged
KW - Neoplasm Grading
KW - Neoplasm Metastasis
KW - Neoplasm Staging
KW - Neoplasms, Second Primary/epidemiology
KW - Prognosis
KW - Proportional Hazards Models
KW - Public Health Surveillance
KW - Registries
UR - http://www.scopus.com/inward/record.url?scp=85048370897&partnerID=8YFLogxK
U2 - 10.1007/s10549-018-4846-3
DO - 10.1007/s10549-018-4846-3
M3 - Journal article
C2 - 29948403
SN - 0167-6806
VL - 171
SP - 489
EP - 499
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
IS - 2
ER -