A trial comparing radiotherapy and surgery for women with breast cancer which has spread to their lymph nodes (AMAROS)

This trial compared surgery with radiotherapy as a treatment for women with breast cancer that has spread to the lymph nodes.

As part of treatment for breast cancer, doctors often remove some or all of the lymph nodes under the arm, to find out whether the breast cancer has spread to these lymph nodes.

The first lymph node that cancer cells reach is known as the sentinel node. In this trial the doctors removed the sentinel node and checked it for cancer cells. This is called a sentinel node biopsy.

Women who have cancer cells in their sentinel node need further treatment to the lymph nodes. This reduces the risk of breast cancer coming back.

When this trial was done, doctors often used surgery to treat women in this situation. But some women had radiotherapy instead, and the research team wanted to find out if one treatment was better than the other.