A shorter more intensive course of radiation therapy that lasts three weeks as opposed to the standard five appears to be just as effective for treating early stage breast cancer said researchers at a conference in Boston on Monday.
The results of a randomized long term study comparing the two therapies were presented by lead author Dr Timothy Whelan who is a radiation oncologist at the Juravinski Cancer Centre at McMaster University in Hamilton, Ontario, Canada. Whelan presented the findings at the plenary session of the 50th Annual Meeting of the American Society for Therapeutic Radiology and Oncology.
Many women with early stage breast cancer have breast conservation treatment comprising surgery to remove the cancerous growth (a “lumpectomy”) followed by 5 weeks of standard radiation therapy on the whole breast to kill off any remaining cancer cells. The treatment typically consists of 15 minutes of daily therapy from Monday to Friday for five weeks.
Whelan and colleagues tested a shorter treatment comprising a more intensive course that also irradiates the whole breast but it only lasts three weeks.
They found the shorter course was just as effective and they also suggested it offered patients more convenience at lower cost, which meant a better quality of life.
The new shorter treatment is called “accelerated hypofractionated whole breast irradiation” and is one third cheaper than the standard five week course, and is also less costly than other new methods such as those that only irradiate part of the breast.
Whelan said while the new method had attracted a lot of interest, mainly because it was cheaper and more convenient, there was insufficient evidence of its long term effectiveness which is why they carried out the study.
“We were surprised that the risk of local recurrence and side effects for women treated with accelerated whole breast irradiation was so low even at 12 years,” said Whelan.
“Our study shows that this treatment should be offered to select women treated with early-stage breast cancer,” he added.
For the study, Whelan and colleagues recruited 1,234 women seeking treatment for early stage breast cancer from April 1993 to September 1996. Each woman was randomly assigned to either receive accelerated whole breast irradiation or the standard whole breast irradiation treatment.
The women were then followed for 12 years after treatment. The results showed that at 10 years after treatment, the cancer had returned locally in 6.2 per cent of the accelerated treatment group compared to 6.7 per cent of the the standard therapy group. Cosmetic outcomes were excellent in both groups, said the researchers.
Whelan concluded that:
“This shorter treatment may not be for everyone, however, I would encourage women whose breast cancer is caught early to talk to their oncologist to see if they are a good candidate for this shorter therapy.”
The press report did not mention where they were intending to publish the study.
After skin cancer, breast cancer is the most common cancer among women in the United States, and it is the second leading cause of death in women after lung cancer, according to the American Cancer Society (ACS). The chance of a woman developing invasive breast cancer sometime during her life is about 1 in 8 and the chance of dying from it is about 1 in 35.
The ACS estimates that about 182,460 women in the US will be diagnosed with invasive breast cancer in 2008 and nearly 40,500 will die of the disease. There are currently 2.5 million breast cancer survivors living in the US.
Rates of breast cancer deaths are going down, probably as a result of earlier detection and improved treatment, said the ACS.
Long-Term Results of a Randomized Trial of Accelerated Hypofractionated Whole Breast Irradiation Following Breast Conserving Surgery in Women with Node-negative Breast Cancer.”
Whelan, T, et al.
Presented at the plenary session at 2:00 p.m. on Monday, September 22, 2008.
At the 50th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Boston, USA.
Source: American Society for Therapeutic Radiology and Oncology, American Cancer Society.
Written by: Catharine Paddock, PhD