Immune system not affected by radiation therapy
Two commonly used radiation treatments for early-stage, node-negative breast cancer have been found to have no effect on the immune system,
and women who receive five-day partial-breast radiation therapy* (PBRT) have improved energy and quality of life compared with women who undergo six weeks of whole-breast radiation therapy (WBRT). These conclusions were drawn from a study, by a team of researchers** led by Dr Kevin Albuquerque, radiation oncologist at the Cardinal Bernardin Cancer Centre, Loyola University Health System, Illinois, USA, Albuquerque, and presented at the Canadian Association of Radiation Oncologists (CARO) 2007 meeting.
WBRT has been the standard treatment for early-stage, small-tumour, node-negative breast cancer. However, both PBRT and WBRT are now commonly used in cancer centres throughout the USA and Canada. Dr Albuquerque added that PBRT is a viable option for women who are eligible, and added that the study could help many women facing treatment.
The study: 30 women aged 45 years+, who had a lumpectomy for early stage, small-tumour, node-negative breast cancer were divided into two groups – i.e. to receive WBRT or PBRT. All the patients partook in psychological tests five times during the study: first, pre-treatment, then three weeks after radiation therapy ended, then six, nine and 15 weeks after therapy.
The tests measured tension, depression, anger, vigour and fatigue; well-being at emotional, physical, functional and social levels; plus aspects specific to breast cancer: appearance, illness, treatment side effects and sexuality. At the time of each test, blood samples were collected to assess natural killer cell activity and the number of circulating lymphocyte subsets, indicators of immune system function.
WBRT targeted the entire breast with large-field radiation, while limiting risk to adjacent healthy tissue.
With PBRT, a catheter is left in the woman for five days. When the patient comes for treatment, this catheter is attached to a machine that delivers a radiation ‘seed’ for therapy. After each treatment the seed is removed and the patient leaves. No radiation seed remains in the breast overnight.
Six weeks after therapy, said Dr Albuquerque, the PBRT women ‘… perceived their life is not so drastically changed. At nine and 15 weeks, the PBRT women perceived less stress than the WBRT women. When analysing six-week data for change from baseline, women who had been treated with PBRT had improved energy and quality of life compared with those who had received WBRT.’
* MammoSite brachytherapy
** Loyola researchers: Linda Janusek PhD RN and Linda Millbrandt RN; radiation oncologist Dr Philip Lobo, Northwest Community Hospital; Herbert Mathews PhD, professor of microbiology and immunology, and breast cancer surgeon Dr Sheryl Gabram (now at Emory University School of Medicine, Atlanta)
This article was published on 10/30/2007