Identification of Predictive Factors for Late Radiotherapy Induced Complications in Post Mastectomy Breast Cancer Survivors

Introduction: Post mastectomy radiotherapy significantly improves locoregional control and survival in breast cancer patients but may lead to late complications such as fibrosis, cardiopulmonary toxicity, and lymphedema, which adversely affect long term quality of life. Identifying patients at higher risk is essential for personalized survivorship care. This study aims to determine predictive factors for late radiotherapy induced complications in post mastectomy breast cancer survivors.Material and methods: This cross-sectional analytical study was conducted in ۲۰۲۵ at hospitals affiliated with Tabriz University of Medical Sciences and included ۷۳ post-mastectomy breast cancer survivors. The study evaluated predictive factors for late radiotherapy-induced complications using demographic, clinical, surgical, oncologic, and dosimetric variables, along with treatment-related characteristics and late toxicity outcomes.Results: Among ۷۳ post mastectomy survivors, late complications were common, particularly skin fibrosis (۳۰.۱۴%) and shoulder limitation (۲۸.۷۷%). Severe toxicity (CTCAE ≥۲) occurred in ۳۵.۶۲% and was associated with higher BMI (P = ۰.۰۰۴), smoking (P = ۰.۰۳۷), mean heart dose (P = ۰.۰۰۱), and lung V۲۰ (P = ۰.۰۰۲). Lung V۲۰ predicted severe events (AUC = ۰.۸۴; cut off = ۲۰.۵۷%; sensitivity = ۸۴.۶۲%; specificity = ۷۲.۳۴%).Conclusion: Late radiotherapy induced complications remain prevalent in post mastectomy breast cancer survivors. Elevated BMI, smoking, and higher cardiopulmonary dose parameters—particularly lung V۲۰—were associated with severe toxicity. These findings highlight the importance of optimizing radiation planning and addressing modifiable risk factors to reduce long term morbidity and improve survivorship outcomes.

کلیدواژه ها:

Breast Cancer Survivorship ، Post Mastectomy Radiotherapy ، Late Radiation Toxicity ، Lung V۲۰