September 22, 2008 - Women with early stage breast cancer who choose lumpectomy and radiation as their treatment option may be able to significantly shorten their total treatment time using three-dimensional conformal radiation therapy (3DCRT) according to new research from the Radiation Therapy Oncology Group (RTOG) presented at ASTRO 2008.
RTOG, an NCI-funded national clinical trials group, is a clinical research component of the American College of Radiology (ACR).
Breast conserving therapy of lumpectomy followed by radiotherapy, with its superior cosmetic result and equivalent survival outcome, is an accepted option instead of mastectomy for many patients with stage I or II breast cancer. A major drawback of standard breast conserving therapy is that it is a more complicated treatment regimen requiring five to seven weeks to complete radiotherapy. Using 3DCRT to more accurately target the radiation and spare uninvolved areas of the breast, RTOG researchers are able to deliver radiation to the tumor bed site in higher doses more quickly thus shortening the post lumpectomy treatment time to one week.
“These are very preliminary but encouraging results for women who need treatment but who also have families, careers and other factors to consider when deciding on breast conservation therapy for cancer," said Frank Vicini, M.D., chief of oncology, Beaumont Hospitals, Royal Oak, Mich. “We are leading a large, National Cancer Institute-sponsored clinical trial to give us more information on the benefits vs. risks of accelerated breast irradiation in one week compared to standard radiation therapy for up to seven weeks.”
The phase II study, RTOG 0319, enrolled 58 women from 24 academic and community institutions in the U.S. and Canada from August 2003 until April 2004. The women enrolled on the study received 3DCRT twice daily, with each dose separated by six hours, for five consecutive days. Fifty-three of the patients were evaluable for efficacy reporting with a median follow-up of 4.0 years. At four years the disease-free survival rate was 84 percent, mastectomy-free survival was 90 percent, and overall survival was 96 percent. This is comparable to published rates for standard therapy.
“RTOG is able to test innovative treatment options such as accelerated partial breast irradiation with 3DCRT in a wide variety of treatment facilities both in the community and in academic centers. This allows us to respond to the needs of community physicians and moves proven, new therapies into general practice faster,” said Walter J. Curran, Jr., the RTOG Group Chair, and the Lawrence W. Davis Professor and chair of the department of radiation oncology in the Emory School of Medicine and chief medical officer of the Emory Winship Cancer Institute.