Interstitial multicatheter HDR-brachytherapy as accelerated partial breast irradiation after second breast-conserving surgery for locally recurrent breast cancer

A Systematic Review and Meta-Analysis on the Role of Repeat Breast-Conserving Surgery for the Management of Ipsilateral Breast Cancer Recurrence

INTRODUCTION

The standard surgical management of ipsilateral breast cancer recurrence (IBCR) in patients previously treated with breast-conserving surgery (BCS) and radiotherapy (RT) is mastectomy. Recent international guidelines provide conflicting recommendations. The aim of this study was to perform a systematic literature review and meta-analysis of the oncological outcomes in patients with IBCR treated with repeat BCS (rBCS).

METHODS

The MEDLINE and EMBASE databases were searched for relevant English-language publications, with no date restrictions. All relevant studies providing sufficient data to assess oncological outcomes (second local recurrence [LR] and overall survival [OS]) of rBCS for the management of IBCR after previous BCS and RT were included (PROSPERO registration CRD42021286123).

RESULTS

Forty-two observational studies met the criteria and were included in the analysis. The pooled second LR rate after rBCS was 15.7% (95% confidence interval [CI] 12.1-19.7), and 10.3% (95% CI 6.9-14.3) after salvage mastectomy. On meta-analysis of comparative studies (n = 17), the risk ratio (RR) for second LR following rBCS compared with mastectomy was 2.103 (95% CI 1.535-2.883; p < 0.001, I² = 55.1%). Repeat RT had a protective effect (coefficient: - 0.317, 95% CI - 0.596 to - 0.038; p = 0.026, I² = 40.4%) for second LR. Pooled 5-year OS was 86.8% (95% CI 83.4-90.0) and 79.8% (95% CI 74.7-84.5) for rBCS and salvage mastectomy, respectively. Meta-analysis of comparative studies (n = 20) showed a small OS benefit in favor of rBCS (RR 1.040, 95% CI 1.003-1.079; p = 0.032, I² = 70.8%). Overall evidence certainty was very low.

CONCLUSIONS

This meta-analysis suggests rBCS could be considered as an option for the management of IBCR in patients previously treated with BCS and RT. Shared decision making, appropriate patient selection, and individualized approach are important for optimal outcomes.

The Role of Interstitial Brachytherapy for Breast Cancer Treatment: An Overview of Indications, Applications, and Technical Notes

Simple Summary

Breast cancer is the most common cancer in the female population. Adjuvant radiotherapy has become increasingly important as conservative treatment. Muticatheter interstitial brachytherapy is a type of radiation technique wherein the radioactive sources are directly implanted into or close to the target tissue and may be considered an extremely precise, versatile, and variable radiation technique. Literature data support muticatheter interstitial brachytherapy as the only method with strong scientific evidence to perform partial breast irradiation and reirradiation after previous conservative surgery and external beam radiotherapy. The aim of our work is to provide a comprehensive view of the use of interstitial brachytherapy, with particular focus on the implant description, limits, and advantages of the technique.

Abstract

Breast cancer represents the second leading cause of cancer-related death in the female population, despite continuing advances in treatment options that have significantly accelerated in recent years. Conservative treatments have radically changed the concept of healing, also focusing on the psychological aspect of oncological treatments. In this scenario, radiotherapy plays a key role. Brachytherapy is an extremely versatile radiation technique that can be used in various settings for breast cancer treatment. Although it is invasive, technically complex, and requires a long learning curve, the dosimetric advantages and sparing of organs at risk are unequivocal. Literature data support muticatheter interstitial brachytherapy as the only method with strong scientific evidence to perform partial breast irradiation and reirradiation after previous conservative surgery and external beam radiotherapy, with longer follow-up than new, emerging radiation techniques, whose effectiveness is proven by over 20 years of experience. The aim of our work is to provide a comprehensive view of the use of interstitial brachytherapy to perform breast lumpectomy boost, breast-conserving accelerated partial breast irradiation, and salvage reirradiation for ipsilateral breast recurrence, with particular focus on the implant description, limits, and advantages of the technique.

Fulvestrant May Falsely Increase 17β-Estradiol Levels in Immunoassays: A Case Report of a 57-Year-Old Postmenopausal Patient With Recurrent Estrogen Receptor-Positive Breast Cancer

The prognosis for female patients with locoregionally recurrent breast cancer has improved with the concurrent local and systemic treatment under multiple disciplinary teams. Radiotherapy is a valuable local treatment measure for unresectable locoregional recurrent breast cancer; however, reirradiation in previously irradiated areas is still a matter of debate. Antihormonal therapy achieves an overall survival benefit for most of these patients with estrogen receptor-positive (ER+) breast cancer in both adjuvant and metastatic settings. Fulvestrant is an ER antagonist and selective ER downregulator widely used in antihormonal therapy, especially in recurrent postmenopausal ER+ breast cancers. However, fulvestrant closely resembles 17β-estradiol in its molecular structure which may result in false increases in serum 17β-estradiol levels in commercially available immunoassays leading to incorrect medical decisions. Herein, we report a case of a 57-year-old postmenopausal patient with recurrent ER+ breast cancer treated with concurrent fulvestrant and reirradiation. There was a good clinical response, and the combination treatment was well tolerable. During the quarterly follow-up, we monitored a gradual increase of the serum 17β-estradiol level in immunoassays, unexpectedly, because the patient underwent natural menopause 8 years ago. To rule out the suspected fulvestrant cross-reactivity with 17β-estradiol in immunoassay, the patient’s serum 17β-estradiol levels were subsequently tested with the more sensitive and specific liquid chromatography-mass spectrometry (LC-MS) method, which confirmed 17β-estradiol levels at the postmenopausal level. Concomitant fulvestrant with reirradiation seems to be a safe and effective therapy for locoregionally recurrent ER+ breast cancer. However, a falsely increased 17β-estradiol may result from cross-reactivity between 17β-estradiol and its molecular analog compounds, for example, fulvestrant. Therefore, it is important for the clinicians with the knowledge of this interaction to prevent unnecessary erroneous interpretation of results and avoid wrong medical decisions.

Re-irradiation for intra-thoracic tumours and extra-thoracic breast cancer: dose accumulation, evaluation of efficacy and toxicity based on a literature review

The improvement seen in the diagnostic procedures and treatment of thoracic tumours means that patients have an increased chance of longer overall survival. Nevertheless, we can still find those who have had a recurrence or developed a secondary cancer in the previously treated area. These patients require retreatment including re-irradiation. We have reviewed the published data on thoracic re-irradiation, which shows that some specific healthy tissues can tolerate a significant dose of irradiation and these patients benefit from aggressive treatment; however, there is a risk of damage to normal tissue under these circumstances. We analysed the literature data on re-irradiation in the areas of vertebral bodies, spinal cord, breast, lung and oesophagus. We evaluated the doses of primary and secondary radiotherapy, the treatment techniques, as well as the local control and median or overall survival in patients treated with re-radiation. The longest OS is reported in the case of re-irradiation after second breast-conserving therapy where the 5-year OS range is 81 to 100% and is shorter in patients with loco-reginal re-irradiation where the 5-y OS range is 18 to 60%. 2-year OS in patients re-irradiated for lung cancer and oesophagus cancer range from 13 to 74% and 18 to 42%, respectively. Majority grade ≥3 toxicity after second breast-conserving therapy was fibrosis up to 35%. For loco-regional breast cancer recurrences, early toxicity occurred in up to 33% of patients resulting in mostly desquamation, while late toxicity was recorded in up to 23% of patients and were mostly ulcerations. Early grade ≥3 lung toxicity developed in up to 39% of patients and up to 20% of Grade 5 hemoptysis. The most frequently observed early toxicity grade ≥3 in oesophageal cancer was oesophagitis recorded in up to 57% of patients, followed by hematological complications which was recorded in up to 50% of patients. The most common late complications included dysphagia, recorded in up to 16.7% of patients. We have shown that thoracic re-irradiation is feasible and effective in achieving local control in some patients. Re-irradiation should be performed with maximum accuracy and care using the best available treatment methods with a highly conformal, image-guided approach. Due to tremendous technological progress in the field of radiotherapy, we can deliver radiation precisely, shorten the overall treatment time and potentially reduce treatment-related toxicities.