RESUMO
Radiotherapy (RT) is an essential part of breast cancer (BC) treatments. Unfortunately, heart exposure to radiation can also impair the long-term survival of patients. Our study aimed to quantify the oncological benefit and the cardiovascular (CV) risk associated with modern RT in a real-world cohort of BC patients. Our descriptive study enrolled BC patients who received adjuvant RT. Ten-year overall survival (OS) was estimated using Predict® version 2.1 (National Health Service, London, UK). The basal risk of CV events was estimated using the American Heart Association (ACC/AHA) CV score. Treatment volumes and mean cardiac doses were obtained from RT treatment plan records. The increased risk of CV events due to RT was estimated using a model proposed by Darby. The risk of acute myocardial infarction or stroke mortality was estimated using HeartScore® (European Society of Cardiology, Brussels, Belgium). A total of 256 BC patients were included in the study. The average age of patients was 57 years old (range: 25-91); 49.6% had left BC. The mean cardiac dose was 166 cGy (interquartile range (IQR) 94-273); the estimated hazard ratio (HR) for CV disease was HR 1.12 (confidence interval (CI) 1.04-1.24). The estimated baseline 10-year CV risk was 5.6% (0.2 to 51.2); CV risk increased by 0.9% (range 0.02-35.47%) after RT. The absolute risk of 10-year mortality from CV disease was 2.5% (0.1-9); RT was associated with an estimated 4.9% survival benefit (3.73-6.07) against BC death and a 0.23% (0.17-0.29) estimated increase in CV mortality. Modern RT decreased 10-year BC mortality by 4% but increased CV mortality by 0.2% in this cohort. Our findings encourage the implementation of personalized adjuvant RT treatments that balance risks and benefits to improve long-term BC patient survival.
RESUMO
BACKGROUND: Although fairly uncommon, loco-regional recurrence in breast cancer (BC) has major consequences for the patient. Several predictors for locoregional have been previously reported from large randomized clinical trials mainly from Europe & North America; data from other geographical areas are somewhat scarce. Here we performed a retrospective review of medical records in a single academic center in Chile, searching for predictors of breast tumor recurrence. RESULTS: Median patient follow up was 61 months, 5 year overall survival (OS) rate was 94.2% (95% CI 93-95.3). We found that 108 out of 2,754 (5.3%) patients had loco-regional recurrence. The 2-year loco-regional control was 98% (95% CI 97.3-98.7) and 5-year was 94% (95% CI 92.6-95.4). Univariate analysis showed a correlation between recurrence and being <50 year-old, positive surgical margins, advanced stage, subtype, and presence of LVI and omission of adjuvant radiotherapy. Only the absence of adjuvant RT was predictor of locoregional recurrence in multivariable (p< 0.001). CONCLUSIONS: Our study population presents high local control of BC. Age, surgical margins, stage, molecular subtype and absence of adjuvant radiotherapy were associated with loco-regional recurrence. Prospective trials and long-term follow up are required in order to confirm these results. MATERIALS AND METHODS: We analyzed medical records from 2,201 BC patients at the Pontificia Universidad Católica de Chile from 1997 to 2016. Collected data included: age at diagnosis, tumor size, axillary involvement, molecular subtype, margin status, histological grade, lympho-vascular invasion (LVI) and ipsilateral recurrence.
