Prolongation of overall treatment time as a cause of treatment failure in early breast cancer: An analysis of the UK START (Standardisation of Breast Radiotherapy) trials of radiotherapy fractionation.
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Date
2016-08-29Author
Haviland, JS
Bentzen, SM
Bliss, JM
Yarnold, JR
START Trial Management Group,
Type
Journal Article
Metadata
Show full item recordAbstract
BACKGROUND: Tests of tumour treatment time effect in patients prescribed post-operative radiotherapy for early breast cancer have focussed on time to start of radiotherapy rather than overall treatment time. The START randomised trials of radiotherapy fractionation provide an opportunity to directly estimate the effect of treatment acceleration. METHODS: Between 1986 and 2002, a total of 5861 women with early breast cancer were recruited into the UK START pilot (START-P), START-A and START-B randomised trials. START-P and START-A tested 13 fractions of 3.0-3.3Gy against 25 fractions of 2.0Gy with a fixed treatment duration of 5weeks for all schedules; START-B tested 15 fractions of 2.67Gy in 3weeks against 25 fractions of 2.0Gy over 5weeks. Estimates of the effect of length of treatment for local-regional relapse and for a measure of late normal tissue effects (change in photographic breast appearance, for patients following breast conserving surgery) were obtained from Cox proportional hazards regression analyses stratified according to trial. RESULTS: At a median follow-up of 10years, 444/5831 (7.6%) patients with data available had a local-regional relapse, and 1135/3185 (35.6%) had mild or marked change in photographic breast appearance by 5years. Adjusting for prognostic factors, the estimate of the overall treatment time effect for local-regional relapse was 0.60Gy/day (95%CI 0.10 to 1.18Gy/day, p=0.02), and 0.14Gy/day (95%CI -0.09 to 0.34Gy/day, p=0.29) for change in photographic breast appearance. CONCLUSIONS: Combined analysis of the START trials generates the hypothesis that overall treatment time is a significant determinant of local cancer control after adjuvant whole breast radiotherapy, with approximately 0.6Gy per day 'wasted' in compensating for tumour cell proliferation.
Collections
Subject
START Trial Management Group
Breast
Humans
Breast Neoplasms
Neoplasm Recurrence, Local
Radiation Injuries
Neoplasm Staging
Treatment Failure
Radiotherapy, Adjuvant
Mastectomy, Segmental
Pilot Projects
Time Factors
Adult
Aged
Aged, 80 and over
Middle Aged
Female
Randomized Controlled Trials as Topic
Young Adult
Dose Fractionation, Radiation
Research team
Clinical Trials & Statistics Unit
Language
eng
Date accepted
2016-08-29
License start date
2016-12
Citation
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 2016, 121 (3), pp. 420 - 423
Publisher
ELSEVIER IRELAND LTD