Evidence to Support Shortened Radiation Therapy for Breast Cancer
We find the increasing information supporting the effectiveness of shorter regimens of radiation therapy good news for breast cancer patients. Radiation therapy is used to help decrease the risk of local recurrences.
It has been shown that with the conventional 5-week regimen of radiation therapy up to 30% of women may avoid getting the treatment due to inconvenience and cost. Shortened courses of radiation therapy for breast cancer are less demanding in time and cost.
Researchers looking at shorter regimens are finding that the 10-year recurrence rates and cosmetic outcomes for breast cancer patients are similar. With the shortened regimens, a greater percentage of women are likely to complete the recommended therapy.
In February this year, a study in the New England Journal of Medicine, compared an intense three-week course of hypofractionated radiation therapy to the standard five-week regimen for women with early-stage breast cancer. The risk of local recurrence at 10 years was found to be similar in both groups: 6.7% among the standard irradiation group compared with 6.2% among the hypofractionated group.
The latest research to support using shortened radiation protocols for breast cancer treatment comes from Jayant Vaidya, PhD, of University College London, and colleagues published online in The Lancet.
Vaidya and colleagues enrolled more than 2,000 patients in a prospective, randomized, non-inferiority trial of women aged 45 years or older with invasive ductal breast carcinoma undergoing breast-conserving surgery. The study involved 28 centers in nine countries.
Patients were randomly assigned in a 1:1 ratio to receive targeted intraoperative radiotherapy (TARGIT) or whole breast external beam radiotherapy. Postoperative discovery of predefined factors (eg, lobular carcinoma) could trigger addition of external beam radiotherapy to targeted intraoperative radiotherapy (in an expected 15% of patients). The primary outcome was local recurrence in the conserved breast.
Of 996 patients who received the allocated treatment in the targeted intraoperative radiotherapy group, 854 (86%) received targeted intraoperative radiotherapy only and 142 (14%) received targeted intraoperative radiotherapy plus external beam radiotherapy. 1025 (92%) patients in the external beam radiotherapy group received the allocated treatment.
The TARGIT approach uses a device that provides a point source of low energy x-rays positioned in the tumor bed for between 20 and 35 minutes to irradiate tissues that are at highest risk of local recurrence.
In the TARGIT group there were 6 local recurrences at 4 years compared to 5 in the external beam group.
Complication frequency was similar for both groups, 3.3% in the TARGIT group and 3.9% in the external beam radiotherapy group. There was one exception to this. The TARGIT group had almost 3 times as many (2.1% versus 0.8%) wound seromas that needed more than three aspirations.
Even though I agree with David Azria, MD, PhD, of INSERM U896 in Montpellier, France, and Céline Bourgier, MD, of Institut Gustave Roussy in Villejuif, France that the results of this trial need to have a longer follow-up, I find it encouraging that shortened courses of radiation therapy may be an option for women.
Shortened Radiation Treatment Works for Breast Cancer
Vaidya JS, et al "Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): an international, prospective, randomised, non-inferiority phase 3 trial" Lancet 2010; DOI:10.1016/S0140-6736(10)60837-9.
Azria D, Bourgier C "Partial breast irradiation: new standard for selected patients." Lancet 2010; DOI:10.1016/S0140-6736(10)60898-7.6736(10)60898-7.
This page is updated on May 18, 2013