Additional radiation reduces breast cancer recurrence in some patients

23 July 2015

Toronto -

A Canadian Cancer Society–funded clinical trial has found a reduction in breast cancer recurrence when radiation is given to the nearby lymph nodes in addition to the standard treatment of whole-breast radiation after breast-conserving surgery (such as lumpectomy). Overall survival was not shown to increase.

The research was conducted over 14 years, led by the Society-funded NCIC Clinical Trials Group at Queen’s University in Kingston. The study examined the effects of adding radiation to regional lymph nodes to the typically prescribed radiation of the whole breast and compared the results to whole-breast radiation alone.

The study involved women whose breast cancer had spread to the lymph glands under the arm (axillary node-positive) or women who didn’t have cancer in the underarm nodes (axillary node-negative), but had cancer with high-risk features.

Currently, many women with early breast cancer are treated with lumpectomies, a breast-conserving surgery where the tumour is removed along with some of the healthy tissue surrounding it. This surgery is then usually followed by radiation to the whole breast.

The technique used in the trial is a treatment that is sometimes used after mastectomy in women with node-positive breast cancer where radiotherapy to the chest wall and regional lymph nodes (under the arm, above the collar bone and under the breast bone) is administered. 

“This trial helps answer an important question about whether the addition of regional lymph node radiation to the standard radiation of the breast improves outcomes in women with breast cancer,” says Dr Siân Bevan, Director of Research, Canadian Cancer Society. “The Canadian Cancer Society is committed to supporting research to ensure that cancer patients receive the best available treatment based on strong scientific evidence, which will also influence treatments in the future.”

Trial leader Dr Tim Whelan is a professor of oncology at McMaster University’s Michael G. DeGroote School of Medicine and a radiation oncologist at Hamilton Health Sciences Juravinski Cancer Centre.

“This study is important because it shows that additional radiation to the surrounding lymph nodes provides added benefit to women, particularly those with involvement of the lymph nodes in the axilla,” said Whelan. “Additional radiation to the surrounding lymph nodes reduced the risk of subsequent recurrence of breast cancer both locally, such as under the arm, and at sites distant from the breast, such as the bone, liver and lung. The treatment did not increase survival, but follow-up is still relatively early.”

Dr Whelan added that further research is necessary to determine which women are most likely to benefit and who may not from the additional radiation. Another study, which was performed in Europe, has showed very similar findings.

This research was published in the New England Journal of Medicine. More than 1,800 women with breast cancer and a team of investigators from Canada, the United States and Australia were involved with the trial.

The Canadian Cancer Society is a national community-based organization of volunteers whose mission is the eradication of cancer and the enhancement of the quality of life of people living with cancer. When you want to know more about cancer, visit our website www.cancer.ca or call our toll-free, bilingual Cancer Information Service at 1 888 939-3333.

For more information, please contact:

Rosie Hales

Communications Specialist

Canadian Cancer Society

National office

Phone: 416 934-5338