Brachytherapy Impact Similar but not Superior to Standard Radiation Therapy
Compared with standard radiation therapy, brachytherapy — a method of confining radiation to the tumor site — may similarly reduce the risk of future mastectomy among some older women with early-stage disease.
This study led by researchers at the University of Texas MD Anderson Cancer Center offers the first direct comparison of the two techniques.
Brachytherapy is a form of radiation therapy in which radiation is given through:
- a series of catheters or tubes placed in the breast that surround the tumor site
- a single tube attached to a balloon that inflates inside the affected breast, where the tumor was removed
Small seeds placed in the tube(s) give off the radiation. These two methods may spare healthy tissue from negative side effects of radiation, affecting only the area of the tumor site. Though today’s radiation techniques are better at protecting healthy areas of your body, standard radiation therapy sometimes affects parts of the ribs, muscles, lungs and heart.
Despite its potential benefits, brachytherapy is not standard of care for breast cancer after lumpectomy. Doctors are not yet sure who gains the most from having brachytherapy instead of standard whole breast radiation therapy, or if certain populations are more likely to have negative side effects.
To learn more, researchers compared medical records of women treated with brachytherapy after lumpectomy, standard whole breast radiation therapy after lumpectomy, and lumpectomy alone.
Researchers reviewed medical records of 35,947 women aged 66 years and older from the Surveillance, Epidemiology and End Results (SEER) – Medicare database. The women all had lumpectomy for early-stage breast cancer or ductal carcinoma in situ, DCIS, between 2002 and 2007.
The trial team collected data on whether the women had any surgery-related issues within 1 year of treatment. They also noted whether women needed mastectomy or were treated for radiation side effects by the end of 2009.
Researchers defined each woman as “suitable,” “cautionary,” or “unsuitable” for brachytherapy, using guidelines created by the American Society of Radiation Oncology, ASTRO. This was done to see if these categories are useful in predicting whether brachytherapy is appropriate in people with certain breast cancer characteristics.
- Suitable women had estrogen receptor-positive, early-stage breast cancer and no lymph nodes testing positive for cancer
- Unsuitable women had larger tumors, some positive lymph nodes, or no lymph nodes assessed
- Cautionary women met suitable requirements but had larger tumors or estrogen receptor-negative disease
The analysis showed:
- Brachytherapy lowers the risk of future mastectomy compared with lumpectomy alone, but not as strongly as does traditional whole breast radiation therapy
- Brachytherapy led to a higher risk of negative breast side effects and post-surgery issues overall
- The ASTRO system predicted the likelihood of future mastectomy for women labeled “suitable”
- These women were the least likely to have future breast removal
Information on whether women took hormonal therapy as directed and whether they had clear margins after surgery was not available. Both factors can impact whether cancer comes back and if future mastectomy is needed.
This study also does not reporton side effects of traditional radiation therapy beyond 2009. Late side effects of radiation to the whole breast less commonly include heart attack and second cancers.
What This Means for You
If you are a woman with estrogen receptor-positive, early-stage breast cancer and no positive lymph nodes, choosing brachytherapy may be an option for you.
Though short-term side effects were more common in women receiving brachytherapy, the treatment did lower the chance of future mastectomy at the start of the trial when compared with those treated with lumpectomy alone. The technique may also be associated with fewer long-term risks than standard radiation.
Keep in mind that data for this study were taken from 7 to 10 year-old medical records. Improvements in technology might lead to better results from brachytherapy given today.
Share these findings with your radiation oncologist who will be able to discuss what treatment is best for you.
Smith, G, Jiang, J, Buccholz, T, Xu, Y, Hoffman, K, et al. Benefit of adjuvant brachytherapy versus external beam radiation for early breast cancer: impact of patient stratification on breast preservation. International Journal of Radiation Oncology Biology Physics. 2014; 88 (2): 274-284.