Omission of adjuvant radiotherapy for older adults with early-stage breast cancer particularly in the COVID era: A literature review (on the behalf of Italian Association of Radiotherapy and Clinical Oncology)

A systematic review and meta-analysis of intraoperative electron radiation therapy delivered with a dedicated mobile linac for partial breast irradiation in early breast cancer

•PBI is valid alternative to WBI in patients at low-risk of local relapse. •PBI is delivered by means of various techniques, one of which is IOeRT. •After IOeRT, an unexpectedly high LR rate was observed in the only phase III RCT. •Patient selection impacts on LR rates after IOeRT. •With appropriate patient selection IOeRT outcomes overlap with other RT techniques.

Omission of Radiotherapy in Women >60 Years Old After Breast Conserving Surgery for Breast Cancer is Non-Inferior in Terms of Local Recurrence: A Retrospective Cohort Study

Objective

Local recurrence rate may show no significant differences between women aged 60 and older who receive breast-conserving surgery followed by radiotherapy and those in the same age group who undergo breast-conserving surgery without subsequent radiotherapy.

Materials and Methods

Retrospective cohort study from a single practice with median follow-up time 44 months (interquartile range: 16, 82), comparing women older than 60 years old at diagnosis of breast cancer, treated with breast conserving surgery and either receiving or not receiving radiation therapy postoperatively. The primary endpoint was local recurrence difference between the two groups.

Results

Local recurrence did not differ significantly between the two groups in terms of radiotherapy or not [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.89-1.02, Fisher's exact test p = 0.388], nor between two age groups with cut-off at 65 years of age (OR: 0.99, 95% CI 0.92-1.07, Fisher's Exact test p = 0.6). Local recurrence also did not differ when subgroups of age (60-65 years and >66 years) were considered. All patients received 5 years of hormonal therapy.

Conclusion

Omission of radiotherapy in selected patients is not inferior to radiotherapy after breast conserving surgery in terms of preventing local recurrence.

Recent Advances in Optimizing Radiation Therapy Decisions in Early Invasive Breast Cancer

Adjuvant whole breast irradiation after breast-conserving surgery is a well-established treatment standard for early invasive breast cancer. Screening, early diagnosis, refinement in surgical techniques, the knowledge of new and specific molecular prognostic factors, and now the standard use of more effective neo/adjuvant systemic therapies have proven instrumental in reducing the rates of locoregional relapses. This underscores the need for reliably identifying women with such low-risk disease burdens in whom elimination of radiation from the treatment plan would not compromise oncological safety. This review summarizes the current evidence for radiation de-intensification strategies and details ongoing prospective clinical trials investigating the omission of adjuvant whole breast irradiation in molecularly defined low-risk breast cancers and related evidence supporting the potential for radiation de-escalation in HER2+ and triple-negative clinical subtypes. Furthermore, we discuss the current evidence for the de-escalation of regional nodal irradiation after neoadjuvant chemotherapy. Finally, we also detail the current knowledge of the clinical value of stromal tumor-infiltrating lymphocytes and liquid-based biomarkers as prognostic factors for locoregional relapse.

Are we overtreating stage I triple-negative breast cancer in Ontario? A population-based retrospective epidemiological analysis using the ICES database

Triple-negative breast cancer (TNBC) is associated with inferior outcomes. The use of adjuvant chemotherapy is the mainstay of treatment, and its efficacy was demonstrated to be correlated with tumor size. Different guidelines exist regarding chemotherapy in early-stage TNBC. This study uses ICES database to examine the outcomes of the use of adjuvant chemotherapy in stage I TNBC in Ontario stratified by tumor size. Records of TNBC patients diagnosed in 2012 to 2014 were collected from ICES database. Stage I patients were analyzed by tumor size: T1a (≤ 0.5 cm), T1b (> 0.5 cm and ≤ 1.0 cm), and T1c (> 1.0 cm and ≤ 2.0 cm). Kaplan-Meier curves, log-rank test statistic, and Cox's proportional hazard regression were used to compare differences in overall survival (OS) between chemotherapy and no-chemotherapy groups. Of 610 patients, 183 had tumor sizes ≤ 1 cm, representing stages T1aN0M0 and T1bN0M0, and 427 had tumors > 1 cm to 2 cm, representing stage T1cN0M0. Patients with tumors ≤ 1 cm who received chemotherapy did not have a significant difference in OS compared to the no-chemotherapy group (p = 0.41, hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.021-2.5). However, patients with tumor sizes > 1 cm to 2 cm who received chemotherapy demonstrated significantly better OS compared to those without (p = 0.023, HR = 0.40, 95% CI 0.16-0.86). Patients with TNBC stage T1cN0M0 should receive adjuvant chemotherapy. For TNBC tumors ≤ 1 cm, avoidance of chemotherapy can be considered. Prospective research should further investigate the efficacy of chemotherapy in TNBC stages T1a-bN0M0.Trial Registration University of Windsor REB#16-119.

Ways to improve breast cancer patients' management and clinical outcome: The 2020 Assisi Think Tank Meeting

We report on the third Assisi Think Tank Meeting (ATTM) on breast cancer, a brainstorming project which involved European radiation and clinical oncologists who were dedicated to breast cancer research and treatment. Held on February 2020, the ATTM aimed at identifying key clinical questions in current clinical practice and "grey" areas requiring research to improve management and outcomes. Before the meeting, three key topics were selected: 1) managing patients with frailty due to either age and/or multi-morbidity; 2) stereotactic radiation therapy and systemic therapy in the management of oligometastatic disease; 3) contralateral breast tumour prevention in BCRA-mutated patients. Clinical practice in these areas was investigated by means of an online questionnaire. In the lapse period between the survey and the meeting, the working groups reviewed data, on-going studies and the clinical challenges which were then discussed in-depth and subjected to intense brainstorming during the meeting; research protocols were also proposed. Methodology, outcome of discussions, conclusions and study proposals are summarized in the present paper. In conclusion, this report presents an in-depth analysis of the state of the art, grey areas and controversies in breast cancer radiation therapy and discusses how to confront them in the absence of evidence-based data to guide clinical decision-making.

Covid-19 and radiotherapy: a systematic review after 2 years of pandemic

Introduction

Following the Covid-19 pandemic spread, changes in clinical practice were necessary to limit the pandemic diffusion. Also, oncological practice has undergone changes with radiotherapy (RT) treatments playing a key role.Although several experiences have been published, the aim of this review is to summarize the current evidence after 2 years of pandemic to provide useful conclusions for clinicians.

Methods

A Pubmed/MEDLINE and Embase systematic review was conducted. The search strategy was "Covid AND Radiotherapy" and only original articles in the English language were considered.

Results

A total of 2.733 papers were obtained using the mentioned search strategy. After the complete selection process, a total of 281 papers were considered eligible for the analysis of the results.

Discussion

RT has played a key role in Covid-19 pandemic as it has proved more resilient than surgery and chemotherapy. The impact of the accelerated use of hypofractionated RT and telemedicine will make these strategies central also in the post-pandemic period.