Reconstructive complications and early toxicity in breast cancer patients treated with proton-based postmastectomy radiation therapy

BackgroundPostmastectomy radiation therapy (PMRT) decreases the risk of locoregional recurrence and increases overall survival rates in patients with high-risk node positive breast cancer. While the number of breast cancer patients treated with proton-based PMRT has increased in recent years, there is limited data on the use of proton therapy in the postmastectomy with reconstruction setting. In this study, we compared acute toxicities and reconstructive complications in patients treated with proton-based and photon-based PMRT.MethodsA retrospective review of our institutional database was performed to identify breast cancer patients treated with mastectomy with implant or autologous reconstruction followed by PMRT from 2015 to 2020. Baseline clinical, disease, and treatment related factors were compared between the photon-based and proton-based PMRT groups. Early toxicity outcomes and reconstructive complications following PMRT were graded by the treating physician.ResultsA total of 11 patients treated with proton-based PMRT and 26 patients treated with photon-based PMRT were included with a median follow-up of 7.4 months (range, 0.7-33 months). Six patients (55%) in the proton group had a history of breast cancer (3 ipsilateral and 3 contralateral) and received previous RT 38 months ago (median, range 7-85). There was no significant difference in mean PMRT (p = 0.064) and boost dose (p = 0.608) between the two groups. Grade 2 skin toxicity was the most common acute toxicity in both groups (55% and 73% in the proton and photon group, respectively) (p = 0.077). Three patients (27%) in the proton group developed grade 3 skin toxicity. No Grade 4 acute toxicity was reported in either group. Reconstructive complications occurred in 4 patients (36%) in the proton group and 8 patients (31%) in photon group (p = 0.946).ConclusionsAcute skin toxicity remains the most frequent adverse event in both proton- and photon-based PMRT. In our study, reconstructive complications were not significantly higher in patients treated with proton- versus photon-based PMRT. Longer follow-up is warranted to assess late toxicities

Cardiovascular Toxicities of Breast Cancer Treatment: Emerging Issues in Cardio-Oncology

Cancer and cardiovascular disease (CVD) are the two most common causes of mortality and morbidity worldwide. The incidence of both cancer and cardiovascular disease increases with age. With increased life expectancy, the burden of both these diseases will increase substantially in coming years. Patients with CVD share multiple common risk factors and lifestyle behaviors in addition to frequently suffering from multiple comorbid conditions. Tobacco use, hypertension, high cholesterol, diabetes, physical inactivity, and poor nutrition are all established risk factors of heart disease. Patients with diseases such as breast cancer may develop CVD from treatment, such as use of chemotherapy and RT. Effects on the heart are a potentially significant and serious clinical problem in radiation therapy treatment of breast cancer. Over the course of the past 50 years, there have been great advances in the delivery of RT due to the development of new techniques, beam energy, improvement in imaging modalities, and development of image registration strategies. It is hypothesized that cardiac damage from RT is correlated to the dose absorbed by the heart and differs between left- and right-breast radiotherapy. The damage to cardiac micro- and macro-vasculature is the pathophysiological cause of RT-related heart disease. Given the growing clinical relevance of cardio-oncology, this Frontiers in Oncology Research Topic provides a venue for disseminating focused reviews and cutting edge research in this quickly growing field. We encourage submission of original papers and reviews dealing with cardiac toxicity after breast cancer treatment, motion management to reduce cardiac exposure, imaging to evaluate potential cardiac toxicities and primary prevention of cardiac disease in the breast cancer patient