Nadia Obi1, Christine Eulenburg2, Petra Seibold3, Ursula Eilber3, Kathrin Thöne4, Sabine Behrens3, Jenny Chang-Claude5, Dieter Flesch-Janys6. 1. Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: n.obi@uke.de. 2. Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany; Medical Statistics and Decision Making, Department for Epidemiology, University of Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands. 3. Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg, Germany. 4. Department of Cancer Epidemiology/Clinical Cancer Registry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. 5. Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg, Germany; Genetic Tumor Epidemiology Group, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. 6. Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany; Department of Cancer Epidemiology/Clinical Cancer Registry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
Abstract
BACKGROUND: Studies of cohorts of breast cancer (BC) patients diagnosed before 1990 showed radiotherapy (RT) to be associated with increased cardiovascular (CVD) and lung cancer mortality many years after diagnosis. In the late 1990s, improvements in RT planning techniques reduced radiation doses to normal tissues. Recent studies did not consistently report higher RT-related mortality for CVD and second cancers. Aim of the study was to analyze specific causes of death after 3D-conformal RT in a recent BC cohort. METHODS: Stage I-III BC patients diagnosed 2001-2005 and enrolled in the population based MARIEplus study were followed-up for 11.9 years (median). Associations between adjuvant RT and cause-specific mortality were analyzed by using competing risks models, yielding subdistribution hazard ratios (SHR) for RT directly related to cumulative incidences. Models were adjusted for differences in baseline characteristics applying inverse-probability-of-treatment-weighting (IPTW). RESULTS: Of the 2951 patients, 2439 (83.0%) received RT. No significant association of RT with lung cancer mortality (SHRIPTW 0.88, 0.35-2.12), other cancer mortality (SHRIPTW 1.04, 95% CI 0.62-1.73) or cardiac mortality was observed (SHRIPTW 1.57, 0.75-3.29). Mortality from lung and other diseases were significantly lower in irradiated women (SHRIPTW 0.39, 95% CI 0.17-0.90 and SHRIPTW 0.58, 95% CI 0.34-0.97, respectively). CONCLUSION: In line with recent studies, 3D-conformal RT did not significantly increase mortality from non-BC causes in the German MARIEplus cohort. Since long-term data are still sparse and event rates low in BC-cohorts, who received modern RT, investigation of possible late RT effects on mortality beyond 14 years of follow-up is warranted.
BACKGROUND: Studies of cohorts of breast cancer (BC) patients diagnosed before 1990 showed radiotherapy (RT) to be associated with increased cardiovascular (CVD) and lung cancer mortality many years after diagnosis. In the late 1990s, improvements in RT planning techniques reduced radiation doses to normal tissues. Recent studies did not consistently report higher RT-related mortality for CVD and second cancers. Aim of the study was to analyze specific causes of death after 3D-conformal RT in a recent BC cohort. METHODS: Stage I-III BC patients diagnosed 2001-2005 and enrolled in the population based MARIEplus study were followed-up for 11.9 years (median). Associations between adjuvant RT and cause-specific mortality were analyzed by using competing risks models, yielding subdistribution hazard ratios (SHR) for RT directly related to cumulative incidences. Models were adjusted for differences in baseline characteristics applying inverse-probability-of-treatment-weighting (IPTW). RESULTS: Of the 2951 patients, 2439 (83.0%) received RT. No significant association of RT with lung cancer mortality (SHRIPTW 0.88, 0.35-2.12), other cancer mortality (SHRIPTW 1.04, 95% CI 0.62-1.73) or cardiac mortality was observed (SHRIPTW 1.57, 0.75-3.29). Mortality from lung and other diseases were significantly lower in irradiated women (SHRIPTW 0.39, 95% CI 0.17-0.90 and SHRIPTW 0.58, 95% CI 0.34-0.97, respectively). CONCLUSION: In line with recent studies, 3D-conformal RT did not significantly increase mortality from non-BC causes in the German MARIEplus cohort. Since long-term data are still sparse and event rates low in BC-cohorts, who received modern RT, investigation of possible late RT effects on mortality beyond 14 years of follow-up is warranted.
Authors: Hiltrud Merzenich; Dan Baaken; Marcus Schmidt; Inga Bekes; Lukas Schwentner; Wolfgang Janni; Achim Woeckel; Detlef Bartkowiak; Thomas Wiegel; Maria Blettner; Daniel Wollschläger; Heinz Schmidberger Journal: Breast Cancer Res Treat Date: 2021-10-09 Impact factor: 4.872