Last Updated: 2003-08-19 16:00:44 -0400 (Reuters Health)

NEW YORK (Reuters Health) - After lumpectomy for early-stage breast cancer, radiation treatment is usually applied to the whole breast. Now new research suggests that "limited-field" radiation treatment is just as good for preventing cancer recurrence.

It has been known for some time that breast-sparing surgery plus radiation therapy is as effective as mastectomy for treating early-stage breast cancer. However, it hasn't been clear if the radiation must cover the whole breast or just the area of the cancer.

If limited-field radiotherapy is feasible, it should entail fewer side effects and be easier to administer.

To compare the two strategies, Dr. Frank A. Vicini and colleagues, from William Beaumont Hospital in Royal Oak, Michigan, analyzed data from 199 women treated with limited-field radiotherapy and 199 matched patients treated with whole-breast radiotherapy.

As they report in the Journal of the National Cancer Institute, the researchers found that the rate of cancer recurrence after five years was the same in both groups -- 1 percent.

"The importance of the current study is that it represents, to our knowledge, the largest group of patients treated with limited-field radiation therapy and it has the longest follow-up, which is critical in assessing the potential efficacy of limited-field radiation therapy before proceeding with phase III clinical trials," the team says.

In a commentary in the journal, Dr. C. Norman Coleman and colleagues, from the National Cancer Institute in Bethesda, Maryland, say that such a clinical trial will "provide definitive answers for those physicians and patients yet to face the decision about treatment options for early stage breast cancer."