A trial looking at different radiotherapy schedules for treating breast cancer (START B)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 3

This trial looked at different ways of giving radiotherapy after surgery for early stage breast cancer. This trial was supported by Cancer Research UK.

Many women have radiotherapy after surgery for early stage breast cancer. This is to reduce the risk of the cancer coming back in the breast. There are different ways of having radiotherapy, which you may hear called schedules. A schedule includes the number of doses you have and how big each dose is. A radiotherapy dose is called a fraction and is measured in units called ‘grays’.

This trial compared 2 different schedules for women who have had surgery to remove early stage breast cancer. The aim of the trial was to find out which one

Is best at stopping breast cancer coming back after surgery
Causes the fewest side effects

There are 2 START trials – START A and START B. This information is about START B. There is information about START A on a separate entry in the trials database.

Summary of results

The research team found that having fewer, larger doses, but a lower total dose of radiotherapy is as safe and works as well as the standard higher dose for women with early stage breast cancer.

The trial recruited 2,215 women into one of 2 groups. There were just over 1,100 in each group.

Group 1 had radiotherapy 5 times a week for 5 weeks, with a total dose of 50 gray in 25 doses of 2 gray
Group 2 had radiotherapy 5 times a week for 3 weeks, with a total dose of 40 gray in 15 doses of 2.67 gray.

After an average follow up of 6 years, the number of women whose cancer came back in the breast was low. It was 3.3 per 100 (3.3%) for women in group 1 and 2.2 per 100 (2.2%) in group 2.

They also looked at effects on normal tissue. Just under half of the women taking part had photographs of their breast taken before radiotherapy, and again 2 years after treatment. These showed that fewer women in group 2 had changes in the appearance of their breast than women in group 1.

Over 1,000 women completed quality of life questionnaires. Changes in the appearance of the beast or breast hardness were the most common changes that they reported. This affected up to 4 out of 10 women. Women in group 2 reported fewer changes in the way the breast looked than women in group 1.

Pain in the arm and shoulder affected up to a third of the women taking part. This was about the same for women in both groups.

In 2013, the trial team published more long term results. Having monitored the women in the trial for nearly 10 years, they found that the number of women whose cancer had come back in the breast was still similar in both groups, and there were fewer adverse changes in the breast for women in group 2.

This confirmed their 5 year findings that the 15 dose schedule of radiotherapy works as well as the 25 dose schedule.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.