Breast cancer tumours can be kept under control with fewer, larger doses of radiotherapy, research has shown.
In one trial, patients received 39 grays (the unit used to measure the strength of radiotherapy) or 41.6 grays in 13 fractions over five weeks and in the other, 40 grays in 15 fractions over three weeks. In both cases tumours were kept under similar degrees if control compared with standard radiotherapy treatment.
About 40% of over 2,000 women questioned reported moderate or marked changes to the breast in the five years after treatment. All received surgery for early-stage breast cancer and radiotherapy and one-third suffered arm and shoulder pain linked to earlier treatment.
The lower overall course of radiotherapy saw fewer skin changes in the clinical trial and other side effects like hardness, swelling, sensitivity and pain and stiffness were similar among women given the new regime and the standard dose. Breast hardness (41%) and change in breast appearance (39%) were the most frequently reported effects.
The international standard dose of radiotherapy is 50 grays delivered in 25 fractions (treatments) over five weeks.
The study, published in the journal The Lancet Oncology, was part of the Start trials involving 4,451 patients and was funded by Cancer Research UK, the Medical Research Council and the Department of Health.
Professor John Yarnold, chief investigator of the trial from the ICR, said: “Using women’s personal ratings of the side-effects they experienced since treatment for early breast cancer gives us a unique insight into the effects of the lower dose of radiotherapy compared to the international standard.”