Time interval from breast-conserving surgery to breast irradiation in early stage node-negative breast cancer: 17-year follow-up results and patterns of recurrence

Breast Cancer Management During the COVID-19 Pandemic: the Radiation Oncology Perspective

Purpose of Review

The coronavirus disease 19 (COVID-19) pandemic has caused disruption in healthcare throughout the world. The limitations placed on hospital resources and the need to limit potential exposure to SARS-CoV-2 for both patients and healthcare staff have affected oncologic care for patients with breast cancer (BC), including radiation therapy (RT). This review highlights published guidelines regarding the provision of radiotherapy for BC patients and their adoption by radiation oncology centers.

Recent Findings

Multiple international and national consortiums plus select institutions have published formal recommendations regarding radiation therapy for BC during the COVID-19 pandemic. They embody the principles of limiting in-person visits, proper triage, and the judicious use of delay, abbreviation, or omission of RT as appropriate.

Summary

Since the start of the pandemic, multiple publications have provided guidance regarding RT for BC during this challenging time. The pandemic has led to increased use of telemedicine and abbreviated radiation therapy courses in the setting of BC, which are likely to persist. Future research is needed to establish the effect of these changes on oncologic outcomes.

Association between waiting time for radiotherapy after surgery for early-stage breast cancer and survival outcomes in Ontario: a population-based outcomes study

Background

After surgery for early-stage breast cancer (bca), adjuvant radiotherapy (rt) decreases the risk of locoregional recurrence and death from bca. It is unclear whether delays to the initiation of adjuvant rt are associated with inferior survival outcomes.

Methods

This population-based retrospective cohort study included a random sample of 25% of all women with stage i or ii bca treated with adjuvant rt in Ontario between 1 September 2001 and 31 August 2002, when, because of capacity issues, wait times for radiation were abnormally long. Pathology reports were manually abstracted and deterministically linked to population-level administrative databases to obtain information about recurrence and survival outcomes. Cox proportional hazards modelling was used to evaluate the association between waiting time and survival outcomes. A composite survival outcome was used to ensure that all possible measurable harms of delay would be captured. The composite outcome, event-free survival, included locoregional recurrence, development of metastatic disease, and bca-specific mortality.

Results

We identified 1028 women with stage i or ii bca who were treated with breast-conserving surgery and adjuvant rt. For the 599 women who were treated with adjuvant radiation without intervening chemotherapy, a waiting time of 12 weeks or more from surgery to the start of radiation appeared to be associated with worse event-free survival after a median follow-up of 7.2 years (hazard ratio for the composite outcome: 1.44; 95% confidence interval: 0.98 to 2.11; p = 0.07). For the 429 women who received intervening adjuvant chemotherapy, a waiting time of 6 weeks or more from completion of chemotherapy to start of radiation was associated with worse event-free survival after a median follow-up of 7.4 years (hazard ratio: 1.50; 95% confidence interval: 1.00 to 2.22; p = 0.047).

Conclusions

Delay to the initiation of adjuvant rt after breast-conserving surgery is associated with inferior bca survival outcomes. The good prognosis for patients with early-stage bca limits the statistical power to detect an effect of delay to rt. Given that there is no plausible advantage to delay, we agree with Mackillop that time to initiation of rt should be kept "as short as reasonably achievable."

The influence of timing of radiation therapy following breast-conserving surgery on 10-year disease-free survival

Background:

The Dutch guidelines advise to start radiation therapy (RT) within 5 weeks following breast-conserving surgery (BCS). However, much controversy exists regarding timing of RT. This study investigated its effect on 10-year disease-free survival (DFS) in a Dutch population-based cohort.

Methods:

All women diagnosed with primary invasive stage I-IIIA breast cancer in 2003 treated with BCS+RT were included. Two populations were studied. Population 1 excluded patients receiving chemotherapy before RT. Analyses were stratified for use of adjuvant systemic therapy (AST). Population 2 included patients treated with chemotherapy, and compared chemotherapy before (BCS-chemotherapy-RT) and after RT (BCS-RT-chemotherapy). DFS was estimated using multivariable Cox regression. Locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were secondary outcomes.

Results:

Population 1 (n=2759) showed better DFS and DMFS for a time interval of >55 than a time interval of <42 days. Patients treated with AST showed higher DFS for >55 days (hazards ratio (HR) 0.60 (95% confidence interval (CI): 0.38–0.94)) and 42–55 days (HR 0.64 (95% CI: 0.45–0.91)) than <42 days. Results were similar for DMFS, while timing did not affect LRRFS and OS. For patients without AST, timing was not associated with DFS, DMFS and LLRFS, but 10-year OS was significantly lower for 42–55 and >55 days compared to <42 days. In population 2 (n=1120), timing did not affect survival in BCS-chemotherapy-RT. In BCS-RT-chemotherapy, DMFS was higher for >55 than <42 days.

Conclusions:

Starting RT shortly after BCS seems not to be associated with a better long-term outcome. The common position that RT should start as soon as possible following surgery in order to increase treatment efficacy can be questioned.

The iBRA-2 (immediate breast reconstruction and adjuvant therapy audit) study: protocol for a prospective national multicentre cohort study to evaluate the impact of immediate breast reconstruction on the delivery of adjuvant therapy

INTRODUCTION

Immediate breast reconstruction (IBR) is routinely offered to improve quality of life for women with breast cancer requiring a mastectomy, but there are concerns that more complex surgery may delay the delivery of adjuvant oncological treatments and compromise long-term oncological outcomes. High-quality evidence, however, is lacking. iBRA-2 is a national prospective multicentre cohort study that aims to investigate the effect of IBR on the delivery of adjuvant therapy.

METHODS AND ANALYSIS

Breast and plastic surgery centres in the UK performing mastectomy with or without (±) IBR will be invited to participate in the study through the trainee research collaborative network. All women undergoing mastectomy ± IBR for breast cancer between 1 July and 31 December 2016 will be included. Patient demographics, operative, oncological and complication data will be collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR will be compared to determine the impact that IBR has on the time of delivery of adjuvant therapy. Prospective data on 3000 patients from ∼50 centres are anticipated.

ETHICS AND DISSEMINATION

Research ethics approval is not required for this study. This has been confirmed using the online Health Research Authority decision tool. This novel study will explore whether IBR impacts the time to delivery of adjuvant therapy. The study will provide valuable information to help patients and surgeons make more informed decisions about their surgical options. Dissemination of the study protocol will be via the Mammary Fold Academic and Research Collaborative (MFAC) and the Reconstructive Surgery Trials Network (RSTN), the Association of Breast Surgery (ABS) and the British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS). Participating units will have access to their own data and collective results will be presented at relevant surgical conferences and published in appropriate peer-reviewed journals.