ESTRO 2022

Session Item

Saturday

May 07

10:30 - 11:30

Room D3

Late-breaking

Chair: , United Kingdom;

Chair: , The Netherlands

Session Type: Proffered Papers

Track: Clinical

Journey:

10:40 - 10:50

First results of FAST-Forward phase 3 RCT nodal substudy: 3-year normal tissue effects

Duncan Wheatley, United Kingdom

Presentation Number: OC-0101

Abstract

Abstract Title:

First results of FAST-Forward phase 3 RCT nodal substudy: 3-year normal tissue effects

Authors:

Duncan Wheatley¹, Joanne Haviland², Jaymini Patel², Mark Sydenham², Abdulla Alhasso³, Charlie Chan⁴, Susan Cleator⁵, Charlotte Coles⁶, Ellen Donovan⁷, Anna Kirby⁸, Cliona Kirwan⁹, Zohal Nabi¹⁰, Elinor Sawyer¹¹, Navita Somaiah⁸, Isabel Syndikus¹², Karen Venables¹³, John Yarnold¹⁴, A Murray Brunt¹⁵, Judith Bliss²

¹Royal Cornwall Hospital, Sunrise Cancer Centre, Truro, United Kingdom; ²The Institute of Cancer Research, ICR-CTSU, London, United Kingdom; ³NHS Greater Glasgow and Clyde, The Beatson West of Scotland Cancer Centre , Glasgow, United Kingdom; ⁴Nuffield Health, Breast Surgery, Cheltenham, United Kingdom; ⁵Imperial College Healthcare NHS Trust, Oncology, London, United Kingdom; ⁶Cambridge University Hospitals NHS Foundation Trust, Oncology, Cambridge, United Kingdom; ⁷University of Surrey, Centre for Vision, Speech and Signal Processing, Guildford, United Kingdom; ⁸The Royal Marsden NHS Foundation Trust, Academic Radiotherapy, Sutton, United Kingdom; ⁹University Hospital of South Manchester, Breast Surgery, Manchester, United Kingdom; ¹⁰The Hillingdon Hospitals NHS Foundation Trust, RTTQA , London, United Kingdom; ¹¹Guy’s and St Thomas’ NHS Foundation Trust, Oncology, London, United Kingdom; ¹²The Clatterbridge Cancer Centre NHS Foundation Trust, Radiotherapy, Clatterbridge, United Kingdom; ¹³The Hillingdon Hospitals NHS Foundation Trust, Medical Physics, London, United Kingdom; ¹⁴The Institute of Cancer Research, Academic Radiotherapy, London, United Kingdom; ¹⁵University of Keele, School of Medicine, Stoke on Trent, United Kingdom

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Purpose or Objective

The FAST-Forward main trial showed that a radiotherapy (RT) schedule of 26Gy in 5 fractions (Fr) delivered in 1 week to the breast/chest wall is as safe and effective as a standard 15Fr regimen after primary surgery for early breast cancer. The findings have changed international clinical practice following publication in April 2020. Here, we present interim results of the nodal substudy up to 3-year follow-up. Formal hypothesis testing will await the 5-year primary analysis.

Material and Methods

The FAST-Forward nodal substudy (ISRCTN19906132) randomised patients with invasive breast cancer (pT1-3 pN1-3a M0) after breast conservation or mastectomy to 40Gy/15Fr over 3 weeks, 27Gy or 26Gy/5Fr over 1 week (1:1:1) to level I-IV axilla. The level was specified by the clinician for each patient. A protocol amendment in 12/2017 closed recruitment to 27Gy/5Fr. Centres pre-specified tumour bed boost if required. Main objective was to assess non-inferiority in patient-reported arm/hand swelling (primary endpoint) and function for 5Fr vs 15Fr. Design assumed 5-year 10% moderate/marked arm/hand swelling (EORTC QLQ-BR23) in 40Gy/15Fr with non-inferiority defined as 10% absolute excess in 5Fr schedules (1-sided α=0.05). NTE are assessed by clinicians (annually) and by patients (3, 6, 12, 24, 60m).

Results

467 patients were randomised 04/2016-10/2018 from 50 UK centres (181 40Gy, 182 26Gy, 104 27Gy). Median age was 60yrs; 7%, 53% & 40% were tumour grade 1, 2 & 3 respectively; 26% received a boost (of which 13% 16Gy/8Fr, 58% 10Gy/5Fr, 29% other). Data returns/expected (excluding deaths & withdrawals) were 89% (367/414) 2-year patient questionnaires and 89% (375/420) 3-year clinical follow-up. Patients reported 2-year moderate/marked arm/hand swelling in 13/127 (10%) for 40Gy, 10/134 (7%) for 26Gy and 12/89 (13%) for 27Gy; estimated absolute differences: -2.8% (90%CI -8.6, 3.0) for 26Gy and 5.1% (90%CI -2.9, 13.2) for 27Gy vs 40Gy. 2-year prevalence of other patient-reported NTE were comparable for 26Gy and 40Gy (table). Clinicians reported arm lymphoedema at 3 years in 11/130 (8%) for 40Gy, 15/123 (12%) for 26Gy, 9/85 (11%) for 27Gy.

Conclusion

At 2-3 years’ follow-up there is no early indication that outcomes relating to arm or shoulder adverse effects are different for 26Gy/5Fr compared with the standard 15Fr regimen but definitive assessment of non-inferiority will await the formal primary analysis at 5 years.

Funding

UK NIHR HTA (09/01/47)