The new procedure takes three weeks and is cheaper than the standard treatment, announced the Canada-based medical team at the annual conference of the American Society for Therapeutic Radiology and Oncology in Boston, Massachusetts.
Researchers tested the new treatment, called accelerated irradiation, on 1,234 women with early stage breast cancer between April 1993 and September 1996, and followed the women for 12 years to determine the rate of recurrence.
There has been renewed interest in the new treatment "due to the potential radiation advantages, patient convenience, quality of life and lower costs," said Timothy Whelan, lead author of the study and a radiation oncologist at the Juravinski Cancer Centre at McMaster University in Ontario, Canada.
Long-term effects were a potential concern for the team, Whelan said, but researchers were "surprised that the risk of local recurrence and side effects was so low even at 12 years."
The study shows that at 10 years after treatment, cancer returned locally in 6.2 percent of patients treated with the new accelerated therapy, compared to 6.7 percent for patients treated with standard therapy.
"Our study shows that this treatment should be offered to select women treated with early stage breast cancer," said Whelan.
The study confirmed findings of a similar British study published in March.
A second study by Peter Beitsch at the Medical Center in Dallas, Texas has also found a one-week treatment that is less invasive and more economical than conventional therapies.
The Texas study's clinical trials involved 400 women with early-stage breast cancer, half of whom were given the standard treatment of radiation for the entire breast.
The other 200 women had cancerous tumors removed and received treatment through a single balloon catheter that delivered the radiation through tiny radioactive seeds.
The study, which followed the women for four years after initial treatment, found that the recurrence rate is similar to that seen with conventional procedures.
"Some women live hundreds of miles from a radiation center or they feel they can't take seven weeks off from their jobs," said Breitsch. "These women often end up having mastectomies."
Breast cancer is the leading cause of cancer death among women worldwide, with around 465,000 deaths in 2007, according to estimates from the American Cancer Society.