Women ages 40 and younger with early-stage breast cancer had a reduced risk of cancer returning in the same breast by undergoing an extra dose of radiation after surgery to conserve the breast, followed by standard radiation treatment, researchers said last week at the ASTRO annual meeting in Los Angeles. The additional "boost" dose of radiation reduced the risk of recurrence in the same breast during a 10-year period from nearly 24 percent to 13.5 percent. The effect was seen in women of all ages, though the statistical evidence was strongest among younger women.

The study included 5,500 women who underwent breast-conserving surgeries (lumpectomies) and radiation treatment for stage I and stage II breast cancer. Findings from the study, led by Dr. Harry Bartelink of the Netherlands Cancer Institute, appeared in the August 1 Journal of Clinical Oncology.

The treatment did not appear to help the women live longer, however, the boost radiation meant that fewer patients needed a mastectomy because of a recurrence in the same breast, and this helped them avoid the physical and psychological effects of losing a breast.