Jee Suk Chang1, Byung Kyun Ko2, Jeoung Won Bae3, Jong-Han Yu4, Min Ho Park5, Yongsik Jung6, Ye Won Jeon7, Kyung Hwan Kim1, Jaeyong Shin8, Chang-Ok Suh1, Yong Bae Kim9. 1. Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea. 2. Department of Surgery, Ulsan University Hospital, Ulsan University College of Medicine, Ulsan, South Korea. 3. Department of Breast and Endocrine Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, South Korea. 4. Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. 5. Department of Surgery, Chonnam National University Medical School, Gwangju, South Korea. 6. Department of Surgery, School of Medicine, Ajou University, Suwon, South Korea. 7. Department of Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea. 8. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, South Korea. 9. Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea. ybkim3@yuhs.ac.
Abstract
PURPOSE: To study the late cardiac toxicity of breast radiation therapy (RT) in Asian women. METHODS: Female breast cancer patients in Korea who underwent breast conservation surgery followed by RT from 1990-2012 were identified from two large registries at institution and population levels. Cumulative incidences of acute coronary events (ACE) or cardiac mortality were estimated in relation to the laterality of breast cancer using a competing risks analysis. RESULTS: In an analysis of 2577 women from a single institution, 3.7% were obese (body mass index ≥30), and 3.4% were ever-smokers. Patients with a history of hypertension, diabetes, or coronary artery disease were 17.5, 5.7, and 2.8%, respectively. The mean heart doses were 6.2 and 1.5 Gy for left- and right-sided tumors, respectively. With a median follow-up of 7 (range 1-23) years, the overall and breast cancer-specific survivals at 10 years were 94.9 and 96.5%, respectively. The 10-year cumulative incidence of ACE was 2.96%. The mean time to ACE was 5.2 ± 3.9 years (range 1-17). There was no clinically relevant difference in rates of ACE between left-sided and right-sided patients, with an adjusted hazard ratio of 1.16 (CI 0.59-2.29). An analysis of 24,235 women in a nationwide registry validated these negative findings with respect to cardiac mortality, with an adjusted hazard ratio of 1.52 (CI 0.37-6.25). Increasing age, a higher body mass index, and a history of hypertension or ischemic heart disease were identified as risk factors. CONCLUSIONS: Our findings reassure that excess risk from breast RT may be small in healthy women, most of who not smoke, weigh less, and have fewer risk factors. A validation using a larger data set of National Health Insurance Corporation is ongoing.
PURPOSE: To study the late cardiac toxicity of breast radiation therapy (RT) in Asian women. METHODS: Female breast cancerpatients in Korea who underwent breast conservation surgery followed by RT from 1990-2012 were identified from two large registries at institution and population levels. Cumulative incidences of acute coronary events (ACE) or cardiac mortality were estimated in relation to the laterality of breast cancer using a competing risks analysis. RESULTS: In an analysis of 2577 women from a single institution, 3.7% were obese (body mass index ≥30), and 3.4% were ever-smokers. Patients with a history of hypertension, diabetes, or coronary artery disease were 17.5, 5.7, and 2.8%, respectively. The mean heart doses were 6.2 and 1.5 Gy for left- and right-sided tumors, respectively. With a median follow-up of 7 (range 1-23) years, the overall and breast cancer-specific survivals at 10 years were 94.9 and 96.5%, respectively. The 10-year cumulative incidence of ACE was 2.96%. The mean time to ACE was 5.2 ± 3.9 years (range 1-17). There was no clinically relevant difference in rates of ACE between left-sided and right-sided patients, with an adjusted hazard ratio of 1.16 (CI 0.59-2.29). An analysis of 24,235 women in a nationwide registry validated these negative findings with respect to cardiac mortality, with an adjusted hazard ratio of 1.52 (CI 0.37-6.25). Increasing age, a higher body mass index, and a history of hypertension or ischemic heart disease were identified as risk factors. CONCLUSIONS: Our findings reassure that excess risk from breast RT may be small in healthy women, most of who not smoke, weigh less, and have fewer risk factors. A validation using a larger data set of National Health Insurance Corporation is ongoing.
Entities:
Keywords:
Asian women; Breast cancer; Cardiac mortality; Late toxicity; Radiation therapy
Authors: Won Kyung Cho; Won Park; Doo Ho Choi; Hyejung Cha; Seok Jin Nam; Seok Won Kim; Jeong Eon Lee; Jonghan Yu; Young-Hyuck Im; Jin Seok Ahn; Yeon Hee Park; Ji-Yeon Kim Journal: J Breast Cancer Date: 2018-06-20 Impact factor: 3.588