Among women with early-stage breast cancer, use of brachytherapy to administer radiation therapy may result in more post-operative complications than conventional external beam radiation therapy, and may also increase the likelihood that a woman will later require a mastectomy. These results were presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium.
For women with early-stage breast cancer who are treated with breast-conserving surgery (lumpectomy), surgery is generally followed by radiation therapy in order to reduce the risk of cancer recurrence. Radiation therapy is often delivered to the whole breast from a machine outside the body (external beam radiation therapy). This treatment is commonly delivered on a daily basis for several weeks.
Breast brachytherapy is an alternative to traditional external beam radiation therapy for women who choose breast-conserving surgery. A specialized catheter that contains radioactive material is placed directly into the area of the breast where the cancer was removed. This is often done twice daily over a period of a week or so. Because this approach requires many fewer weeks of treatment than conventional external beam radiation therapy, it may be a much more convenient option for the patient. Information about the safety and efficacy of breast brachytherapy is somewhat limited, however, and clinical trials to address these issues are underway.
While awaiting the results of ongoing clinical trials, researchers at the MD Anderson Cancer Center conducted an analysis of Medicare claims data. The analysis included information about more than 130,000 female Medicare beneficiaries who were diagnosed with invasive breast cancer between 2000 and 2007. All of the women included in the analysis had been treated with breast-conserving surgery followed by either breast brachytherapy or whole-breast external beam radiation therapy.
- Use of brachytherapy increased over time. In 2000, less than 1% of the women had been treated with brachytherapy. By 2007, 13% of women were being treated with brachytherapy.
- Postoperative complications were more common in the brachytherapy group. Infectious complications, for example, developed in 16% of women treated with brachytherapy and 10% of women treated with external beam radiation therapy.
- By five years after treatment, 4% of women treated with brachytherapy had required additional treatment with a mastectomy, compared with 2.2% of women who had received external beam radiation therapy. The researchers note that the higher rate of mastectomy in the brachytherapy group could be due to breast cancer recurrence or breast complications.
These results raise the possibility that breast brachytherapy may be less effective and more apt to cause breast complications than whole-breast external beam radiation therapy. This was not a randomized trial, however, and the results should not be viewed as definitive. Ongoing trials of breast brachytherapy will provide more conclusive information about the risks and benefits of this approach.
Reference: Smith GL, Xu Y, Buchholz TA, Giordano SH, Smith BD. Partial breast brachytherapy is associated with inferior effectiveness and increased toxicity compared with whole breast irradiation in older patients. Presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium. December 6-10, 2011. Abstract S2-1.
Posted December 13, 2011