PITTSBURGH/Miami Beach, Fla. – Concerns about the toxicity of a newer breast cancer treatment called Accelerated Partial Breast Irradiation (APBI) are unfounded, according to a study presented today, at the 53rd meeting of the American Society of Therapeutic Radiation and Oncology, (ASTRO) by Thomas B. Julian, MD, Director, Division of Breast Surgical Oncology at West Penn Allegheny Health System.
Accelerated partial breast irradiation involves limiting radiation therapy to only the tumor site following lumpectomy. The therapy is given twice a day over a period of about a week, compared to conventional external beam radiation which may entail five weekly treatments for four to six weeks. Many oncologists feel APBI is poised to become the standard of treatment for breast cancer patients.
Several small, single-institution studies, however, have reported significant short-term toxicity for 3-D CEBT (conformal external beam therapy), a type of partial-breast irradiation that is now being evaluated in a large clinical trial by the National Surgical Adjuvant Breast and Bowel Project (NSABP B-39/RTOG 0413).
Because of these reports, Dr. Julian and other principal investigators in the NSABP trial thought it necessary to inform ASTRO about the levels of toxicity they have observed in patients being treated with 3-D CEBT.
The trial has enrolled 4,008 patients, 1,458 of whom are receiving 3-D CEBT. With a mean follow-up time of 46.8 months, no significant toxicity-related issues have been noted.
“We are investigating whether this therapy is as effective as irradiating the entire breast in the local management of early-stage breast cancer. The toxicity rates in our trial continue to be acceptably low,” said Dr. Julian. “This trial has many more patients and a longer follow-up time than other trials, and it is critical that we continue to investigate the efficacy of APBI and its impact on patients’ quality of life.”
Norman Wolmark, MD, Chairman of the NSABP and Director of Oncology for WPAHS, is also one of the principal investigators in the NSABP trial along with Joseph P. Costantino, PhD; Frank A. Vicini, MD; Julia R. White, MD; Douglas W. Arthur, MD; Robert R. Kuske, MD; Rachel Rabinovitch, MD; Kathryn A. Winter, MS, and Walter J. Curran Jr., MD.