Accelerated hypofractionated breast radiotherapy with simultaneous integrated boost: a feasibility study

Is FAST FORWARD the Way Forward in Radiotherapy for Locally Advanced Breast Cancer - Learnings From the COVID Pandemic

INTRODUCTION

Low middle-income countries (LMICs), including India, have paucity of external beam radiotherapy (RT) machines leading to prolonged wait times for RT. Delay in delivery of RT has been shown to adversely affect outcomes in locally advanced breast cancer (LABC). With the availability of results of multiple randomized controlled trials, hypofractionated RT delivered over 3 to 4 weeks became the standard of care in breast cancer RT.

METHODS

We conducted a retrospective audit of 172 LABC patients treated with ultrahypofractionated adjuvant RT (radiotherapy completed in 1 week) during the COVID pandemic. Log rank and Cox-regression model used for univariate and multi-variate analyses.

RESULTS

No patient developed grade 3 esophagitis. Grade 2 esophagitis requiring short term narcotic analgesics was seen in 12 (6.9%) patients. Grade 2 or higher toxicity peaked between 2 and 3 weeks after RT. The estimated 2 and 3- year recurrence free survival (RFS) for the cohort is 87.1 % and 81.4 %, respectively. The estimated 2 and 3-year overall survival for the cohort is 95% and 91.3%. On multivariate analysis, presence of extra-nodal extension was found to be an independent factor associated with worse RFS (P = .028).

CONCLUSIONS

FAST FORWARD protocol RT in LABC appears well tolerated.

Hypofractionation for Regional Nodal Irradiation in Breast Cancer: Best of Both the Worlds

Locoregional radiotherapy play an important role in controlling the disease after surgery in patients with breast cancer. Radiotherapy schedules vary from conventional fraction to hypofractionation. The purpose of this review is to get an insight into the data on regional nodal irradiation (RNI) with hypofractionation in patients with breast cancer. This systematic review was constructed in accordance with Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) framework. Electronic databases such as PubMed, Cochrane and EMBASE were searched from January 1, 2023 to March 31, 2023 to identify studies published in English language on hypofractionated RNI in post mastectomy patients. The search was carried out with the National Library of Medicine's Medical Subject Heading (MeSH) terms like "regional nodal irradiation," "hypofractionated" and "hypofractionation in breast cancer" with different Boolean operators (and/or). A manual search of reference lists of included articles was also performed to make sure there were no additional cases unidentified from the primary search. Studies deemed potentially eligible were identified and assessed by same independent reviewers to confirm eligibility. RNI data are mainly from a randomized study from Beijing and pooled data from START trials. There are also data from retrospective and single institutional studies and a few phase II studies with limited number of patients using different dose fractionations and techniques of radiotherapy. Doses used in these trials ranged from 26-47.7 Gy in 5-19 fractions over 1-4 weeks. Grade ≥ 2 pulmonary fibrosis and lymphedema rate ranged from 2%-7.9% and 3%-19.8% respectively. Grade ≥ 2 shoulder dysfunction and brachial plexopathy ranged from 0.2%-28% and 0%-< 1%, respectively. Late effects with a dose range of 26-40 Gy delivered in 5 to 15 fractions over 1-3 weeks were less/similar to conventional fraction. Current data showed lower/similar rates of toxicity with hypofractionated RNI compared with conventional fractionation RNI. Doses of 26 Gy to 40 Gy delivered in 5 to 15 fractions over 1-3 weeks are safe for RNI. With limited data, ultra-hypofractionation 26 Gy/5 fractions/1 week also seems to be safe. However, long-term outcome is awaited and many trials are going on to address its efficacy and safety.

HYPofractionated Adjuvant RadioTherapy in 1 versus 2 weeks in high-risk patients with breast cancer (HYPART): a non-inferiority, open-label, phase III randomised trial

BACKGROUND

Breast cancer is the most common cancer in women. Radiotherapy is an important part of breast cancer treatment after surgery. Breast cancer radiotherapy is usually delivered in 3-5 weeks. This is a long duration for women with breast cancer to stay away from the family and work. We wanted to reduce this duration so that the wages loss and the logistics can be minimised for these patients. Hypofractionation, i.e. high dose per fraction, is delivered in a smaller number of days. In this study, we will compare a 1-week schedule of hypofractionated adjuvant whole breast/chest wall and/or regional nodal radiotherapy against 2 weeks for locoregional disease control, toxicities, quality of life (QoL), survival and second cancers after primary surgery in patients with breast cancer.

METHODS

Eligible patients with breast cancer after mastectomy or breast conserving surgery (BCS) will be treated with a radiotherapy dose of 26 Gy in 5 fractions over 1 week in the study arm and 34 Gy in 10 fractions over 2 weeks in the control arm. The primary endpoint of this noninferiority study will be locoregional tumour control. Secondary endpoints will be early and late radiation toxicities, quality of life, contralateral primary tumours, regional and distant metastases, survival and second cancers. A total of 1018 patients will be randomised (1:1) to receive 1 week or 2 weeks of radiotherapy. An event-driven analysis will be performed after at least 94 patients have documented locoregional recurrences. Acute radiation toxicity will be assessed and scaled according to the RTOG grading system. Late radiation toxicity will be assessed with the Radiation Therapy Oncology Group and the European Organisation for Research and Treatment of Cancer late radiation morbidity scale. Cosmetic assessment will be done using Harvard/NSABP/RTOG breast cosmesis grading scale at baseline and 3 and 5 years. QoL will be assessed with EORTC QLQ-30 and EORTC QLQ-BR 23 at baseline and 3 and 5 years.

DISCUSSION

Hypofractionation reduces treatment time to half while maintaining breast cosmesis and gives control rates equal to conventional fractionation. This is possible because breast tissue can tolerate high dose per fraction. In this study, we presume that 1-week radiotherapy will be non-inferior to 2 week radiotherapy, i.e. disease control will be similar with both the schedules without additional side effects, and QoL of these patients will be maintained. If we are able to achieve these outcomes, then patients will be able to complete their radiotherapy in less duration. There is not much data on regional nodal irradiation with hypofraction in breast cancer. We have used hypofraction for regional nodal irradiation in the past and not encountered any safety issue. If we are able to prove that late-term effects are comparable in the two schedules, it will make the radiation oncologist confident about hypofractionation in breast cancer. As breast cancer is a leading cancer in females and radiation therapy is an integral part of its local management, hypofractionation will help radiation centres worldwide to meet the growing need for radiation treatment in breast cancer, particularly in developing countries where resources are limited. It will also reduce the financial burden on the patient and family. Since we will treat these patients with both simple and complex radiotherapy techniques, it will also be possible for the low-income countries to follow this trial without needing a high-end or expensive radiotherapy equipment as the planning and treatment process will be very simple.

TRIAL REGISTRATION

The trial is registered with ClinicalTrials.gov ID NCT04472845 and CTRI with REF/2020/09/037050.