Cardiac serum marker alterations after intraoperative radiotherapy with low-energy x-rays in early breast cancer as an indicator of possible cardiac toxicity

Long-term oncologic outcome of intraoperative radiotherapy (IORT) with low-energy X-rays as a tumor-bed boost in Korean patients with breast cancer

BACKGROUND

Although the use of intraoperative radiotherapy (IORT) for accelerated partial breast irradiation is growing, there are not many studies on its effectiveness specifically in Asian population. In this study, we aimed to investigate the long-term oncologic outcomes of Korean patients who received IORT with low-energy X-ray as a tumor-bed boost.

METHODS

We conducted phase II, prospective, single-arm trial to evaluate the local toxicity and oncologic outcomes in breast cancer patients receiving IORT with low-energy X-rays as a tumor-bed boost (NCT02213991). Patients underwent IORT as a tumor-bed boost with low-energy X-rays (20 Gy) followed by external beam radiotherapy for whole breast irradiation (46 Gy). Patients diagnosed with early-stage breast cancer or ductal carcinoma in situ who were suitable for lumpectomy were considered eligible. Kaplan-Meier analysis was used to assess oncologic outcomes with an extended follow-up period.

RESULTS

A total of 194 patients underwent IORT between August 2014 and September 2016 according to the protocol outlined in our study. During the median follow-up of 85.6 months, 12 cases (6.19 %) of recurrence were reported, of which 4 (2.06 %) were reported ipsilateral breast tumor recurrence (IBTR) as the first recurrence event. The 5- and 8-year IBTR rates were both 2.1 % (95 % confidence intervals (CIs), 93.8 - 98.9). The 5-year loco-regional recurrence-free survival (LRRFS), recurrence-free survival (RFS), and overall survival (OS) rates were 97.37 %, 96.32 %, and 100 %, respectively.

CONCLUSION

We identified the oncologic safety of IORT with low-energy X-rays as a tumor-bed boost in Korean patients during an extended follow-up period.

Major complications after intraoperative radiotherapy with low-energy x-rays in early breast cancer

PURPOSE

To describe and analyze major local complications after intraoperative radiotherapy (IORT) with low-energy x‑rays during breast-conserving surgery (BCS) in early breast cancer.

METHODS

Ten women out of 408 who were treated with IORT between 2002 and 2017 and subsequently developed a severe local complication requiring surgical intervention were retrospectively identified and analyzed. Demographic, clinical, and surgical parameters as well as complication characteristics and treatment methods were evaluated.

RESULTS

At initial presentation, eight patients (80%) showed redness, six (60%) seroma, six (60%) wound infection, six (60%) suture dehiscence, and four (40%) induration of the former surgical area. Hematoma and necrosis were observed in one case (10%) each. Time interval until appearance of the first symptoms ranged from directly postoperative until 15 years postoperatively (median 3.1 months). Initial treatment modalities comprised antibiotic therapy (n = 8/80%) and transcutaneous aspiration of seroma (n = 3/30%). In the majority of patients, smaller surgical interventions (excision of a necrotic area/fistula [n = 6/60%] or secondary suture [n = 5/50%]) were sufficient to overcome the complication, yet larger interventions such as complex flap surgery and mastectomy were necessary in one patient each.

CONCLUSION

IORT is an efficient and safe treatment method as < 2.5% of all IORT patients experienced major local complications. However, it seems to pose the risk of causing severe local complications that may require lengthy and burdensome treatment. Thorough preoperative counseling, implementation of recommended intraoperative precautions, and high vigilance for first symptoms of complications during follow-up appointments are necessary measures.

Role of Cardiac Biomarkers in Cancer Patients

Simple Summary

Cardiac biomarkers have proved increasingly useful in the various branches of cardiology, not sparing the field of cardio-oncology. With specific reference to the latter subject, they have been investigated as predictors and/or diagnostic and monitoring tools, as well as prognostic factors, with the purpose of allowing the early prevention of many cardiovascular complications related to the direct action of some cancer types or related to the toxicity of its treatments. However, despite this great potential and excellent cost-effectiveness, their usefulness in some areas still seems to be limited due to lack of sufficient specificity or sensitivity. In fact, in clinical practice, while their use is nowadays standard in some circumstances, evidence does not yet support their routine use in other cases.

Abstract

In patients with cancer—and especially some specific subtypes—the heart can be pathologically affected due to the direct action of the tumor or its secretion products or due to the toxicity of some oncological treatments. Cardiac biomarkers have been investigated as inexpensive and easily accessible tools for prediction, early diagnosis, monitoring, or prognosis of various forms of cancer-related cardiac diseases. However, their clinical usefulness was not always clearly demonstrated in every area of cardioncology. For the identification of anthracycline related cardiotoxicity in the very early stages troponins proved to be more efficient detectors than imaging methods. Nevertheless, the lack of a standardized dosage methodology and of cardiotoxicity specific thresholds, do not yet allow to outline the precise way to employ them in clinical routine and to incorporate them into appropriate diagnostic or managing algorithms. Cardiac biomarkers proved also effective in patients with primary cardiac amyloidosis, in which both troponins and natriuretic peptides were able to predict adverse outcome, and carcinoid heart disease, where a precise diagnostic cut-off for N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was identified to screen patients with valvular involvement. Likewise, NT-proBNP proved to be an excellent predictor of postoperative atrial fibrillation (POAF). On the contrary, evidence is still not sufficient to promote the routine use of cardiac biomarkers to early diagnose myocarditis due to immune check points inhibitors (ICIs), radiotherapy induced cardiotoxicity and cardiac complications related to androgenetic deprivation. In this review we present all the evidence gathered so far regarding the usefulness and limitations of these relatively inexpensive diagnostic tools in the field of cardio-oncology.