AT ECCO2017
AMSTERDAM (FRONTLINE MEDICAL NEWS) – Analyses of patient-reported outcomes in the UK START A and B trials show that radiation doses greater than 2 Gy to the supraclavicular fossa or axilla are safe and are associated with acceptable near- and late-term toxicities, trial investigators reported.
The START trials compared standard adjuvant radiation doses and schedules with accelerated, hypofractionated doses in women with early breast cancer.
At the annual San Antonio Breast Cancer Symposium in 2012, lead investigator John Yarnold, MD, professor of clinical oncology at the Institute of Cancer Research in London, reported that a 40-Gy, 15-fraction regimen was associated with fewer adverse events over 10 years of follow-up compared with a 50-Gy, 25-fraction regimen that was at the time the standard in the United States and the United Kingdom.
Here at an annual congress sponsored by the European Cancer Organisation, Dr. Yarnold reported that among 479 patients in the two trials who had lymphatic radiation, there were no significant differences in arm or shoulder pain, swelling, motion problems, or shoulder stiffness between patients who received conventional 2-Gy fractions for a total of 50 Gy, or lower total doses of radiation divided into fractions larger than 2 Gy.
“A post hoc analysis of outcomes in 479 patients treated with radiotherapy fractions larger than 2 Gy to the supraclavicular fossa and/or the axilla raise no concerns in terms of safety or patient acceptability, and it was for this reason that this schedule has been the standard for locoregional radiotherapy in the UK for some years now,” he said.
START (Standardization of Breast Radiotherapy) A enrolled 2,236 patients from 35 UK centers with breast cancer stages T 1-3, nodal stage N0-1, and no distant metastases (M0) and randomly assigned them to 50 Gy in 25 fractions of 2 Gy each over 5 weeks, 39.0 Gy in 13 fractions of 3.0 Gy over 5 weeks, and 41.6 Gy in 13 fractions of 3.2 Gy over 5 weeks.
In START B, 2,215 women were randomly assigned to the 50 Gy or 40 Gy regimens.
As reported in 2012, over a median follow-up of 9.3 years in START A, the 41.6-Gy regimen was similar in its adverse events profile compared with the 50-Gy dose (hazard ratio [HR] 0.94, and the lower-dose regimen also was comparable in efficacy, as measured by the rate of locoregional tumor relapse.
There were numerically but not significantly more relapses in the 39-Gy dose, however.
In START B, the 40-Gy dose was associated with significantly fewer adverse events over a median of 9.9 years of follow-up (HR 0.77). Efficacy was similar, although there was a nonsignificant trend toward superiority for the hypofractionated regimen.
In the post hoc analysis, the investigators looked at adverse events in 479 total patients in START A and B, 365 of whom had completed patient-reported outcome measures on the European Organization for Research and Treatment of Cancer (EORTC) Breast Cancer–Specific Quality of Life Questionnaire (QLQ-BR23).
A total of 262 patients in START A, and 103 in START B completed the questionnaires at 0, 6, 12, 24, and 60 months. Of these patients. The majority in each arm had radiation to the supraclavicular fossa only, and a minority had axilla radiation alone or in addition to supraclavicular fossa radiation.
In START B, 5-year patient reported outcomes of severity of 3 or 4 on a 4-point scale were low in each treatment arm, with arm or hand swelling reported in 10% of patients on 50 Gy, and 6% of patients on 40 Gy, and shoulder stiffness reported in 12% on the 50-Gy dose, vs. 15% on the 40-Gy dose.
Among all 479 patients with clinical assessments at 10 years, there were also no significant differences in either arm edema or shoulder stiffness between patients who received 50 Gy and those who received other, hypofractionated in each of the two trials.
The findings lend support to the Danish Breast Cancer Cooperative Group’s SKAGEN Trial 1 , which is evaluating moderately hypofractionated locoregional adjuvant radiation therapy of early breast cancer combined with a simultaneous integrated boost in patients with an indication for boost, Dr. Yarnold said.
The UK START trials were supported by Cancer Research UK, the Medical Research Council, and the National Cancer Research Institute. Dr. Yarnold reported having no conflicts of interest.
