Women with breast cancer normally get chemotherapy first, radiotherapy next. In the current treatment scenario, women must attend hospital five days a week for five weeks. This involves spending an hour or more queuing for the radiotherapy machine, getting their correct position under it and receiving their daily dose of radiation.

The international standard radiotherapy schedule for early breast cancer, stipulates that women should receive 50 gray of radiation in 25 equal doses over five weeks. But this requires a huge investment of time and effort from the patient, although it reduces the risk of local cancer relapse by nearly 70 percent.

The study involved women with breast cancer in two trials, called Start A and B (Standardization of Breast Radiotherapy Trial). The women attended clinics three days a week over five weeks and received a total dose of between 39 and 41.6 gray, compared with the normal 50 gray.

The findings showed that “reducing the overall dose of radiation by 20 per cent and the number of sessions by 40 per cent cut side effects without increasing cancer recurrence.”

The study published online in Lancet Oncology and The Lancet could also have implications for other cancers of glandular tissue, such as prostate cancer.