Radiotherapy after lumpectomy has breast cancer benefits

Radiation treatment after a lumpectomy almost halves the risk of recurrence after 10 years and reduces the risk of dying from breast cancer, a large European study suggests.

Radiation treatment after a lumpectomy almost halves the risk of recurrence after 10 years and reduces the risk of dying from breast cancer, a large European study suggests.

The analysis of data for 10,801 women with early stage breast cancer treated with breast-conserving surgery and radiation concluded there was an overall 16 per cent decrease in the risk of recurrence of the disease and a four per cent decrease in risk of dying from breast cancer. 
Radiotherapy after breast-conserving surgery substantially reduced the risk of recurrence and moderately reduced the risk of death from breast cancer, researchers found. (Eric Gaillard/Reuters)

"After breast-conserving surgery, radiotherapy to the conserved breast halves the rate at which the disease recurs and reduces the breast cancer death rate by about a sixth," the study authors concluded in Thursday's issue of the medical journal The Lancet.

"The overall findings from these trials show that radiotherapy after breast-conserving surgery not only substantially reduces the risk of recurrence but also moderately reduces the risk of death from breast cancer. These results suggest that killing microscopic tumour [cells] … in the conserved breast with radiotherapy reduces the potential for both local recurrence and distant metastasis."

The proportion of recurrences that were local suggested that the main effect of radiation was to reduce local recurrence, while the reduction in death rate pointed to benefits for distant recurrences, Dr. Sarah Darby of the Early Breast Cancer Trialists' Collaborative Group at the University of Oxford and her co-authors said.

The investigators noted that many aspects of breast cancer care, such as screening, surgery, pathology and radiation treatments, have changed since most of the women entered the clinical trials that were reviewed.

A journal commentator put the benefit into context, saying a 50 per cent reduction in 10-year recurrence exceeds that from chemotherapy alone or hormonal therapy alone, and is about equivalent to the benefits of trastuzumab or Herceptin for people with a certain type of breast cancer called HER-2 disease.

"The data reinforce the important role that radiotherapy has in management of breast cancer," Dr. Thomas  Buchholz, head of the division of radiation oncology at the University of Texas MD Anderson Cancer Center in Houston, said in the commentary.

The study was funded by Cancer Research UK, the British Heart Foundation, the UK Medical Research Council and the University of Oxford.