Women diagnosed with early-stage breast cancer who have lumpectomy usually have radiation therapy after surgery. Radiation therapy after lumpectomy lowers the risk of the breast cancer coming back (recurrence) and makes lumpectomy as effective as mastectomy.
There are two basic ways to deliver radiation. The traditional way is to irradiate the entire breast (whole-breast irradiation) with radiation from an external source. Newer methods deliver radiation internally, or externally in precisely focused three dimensions, to just the area of the breast where the cancer was (partial-breast irradiation). A number of studies are being done to see if the benefits and risks of partial-breast irradiation are similar to whole-breast irradiation.
A study comparing one type of partial-breast irradiation -- multi-catheter internal radiation (also called interstitial needle-catheter brachytherapy, or just brachytherapy) -- to whole-breast irradiation after lumpectomy in older women found that women who had brachytherapy were more likely to have treatment complications and more likely to need a mastectomy in the 5 years after lumpectomy compared to women who had whole-breast irradiation.
The results were published in the May 2, 2012 issue of the Journal of the American Medical Association. Read the abstract of Association Between Treatment With Brachytherapy vs. Whole-Breast Irradiation and Subsequent Mastectomy, Complications, and Survival Among Older Women With Invasive Breast Cancer.
Researchers looked at the records of 92,735 women aged 67 or older who were diagnosed with early-stage breast cancer between 2003 and 2007. All the women had lumpectomy to remove the cancer and all had some type of radiation therapy after surgery:
- 6,952 had brachytherapy
- 85,783 had whole breast irradiation
Compared to women who got whole-breast irradiation, women who got brachytherapy were:
- more likely to have complications right after surgery:
- 16.2% of women who got brachytherapy had an infection in the breast area after surgery compared to 10.3% of women who got whole-breast irradiation
- 16.25% of women who got brachytherapy had other complications after surgery compared to 9.0% of women who got whole-breast irradiation
- more likely to have other complications in the 5 years after surgery:
- 14.6% of women who got brachytherapy had breast pain compared to 11.9% of women who got whole-breast irradiation
- 8.3% of women who got brachytherapy had fat necrosis (breakdown of fat in the breast tissue) compared to 4.1% of women who got whole-breast irradiation
- 4.5% of women who got brachytherapy had a broken rib compared to 3.6% of women who got whole-breast irradiation
- more likely to need a mastectomy in the 5 years after lumpectomy:
- 4.0% of women who got brachytherapy had a mastectomy compared to 2.2% of women who got whole-breast irradiation
Still, both groups of women (brachytherapy vs. whole-breast irradiation) had the same overall survival 5 years after diagnosis:
- 87.7% of women who got brachytherapy were projected to be alive 5 years after diagnosis compared to 87.0% of women who got whole-breast irradiation
This study suggests that brachytherapy probably is a worse option than whole-breast irradiation for older women.
The drawbacks of traditional whole-breast irradiation include daily trips to the hospital for treatment -- usually 5 days a week for 4 to 6 weeks -- and accidentally exposing nearby healthy tissue (the lungs or heart, for example) to radiation.
To overcome these drawbacks, doctors developed partial-breast irradiation techniques. The new techniques deliver more focused and intense radiation therapy over a shorter period of time. Because the radiation is more focused, the hope is that the newer techniques will cause fewer or milder side effects than traditional radiation therapy with the same benefit.
Doctors are looking forward to the results of a very large, ongoing study called NSABP B-39/RTOG 0413 that is looking at the effectiveness and safety of three types of partial-breast irradiation and comparing them to whole-breast irradiation in both younger and older women.
The three partial-breast irradiation techniques being studied in NSABP B-39/RTOG 0413 study are:
- multi-catheter internal radiation or interstitial needle-catheter brachytherapy (the same type evaluated in the study reported on above)
- balloon internal radiation, known by the brand name MammoSite
- 3-D conformal external beam radiation (3DCRT)
Brachytherapy uses radioactive "seeds" to deliver radiation directly to the area where the cancer was. The seeds are placed in very small tubes (catheters) that are stitched into place under the skin. The seeds are left in the tubes for a few hours or a few days. You remain in the hospital during treatment. Once the treatment is completed, the seeds, tubes, and stitches are removed and you go home.
The MammoSite system places a special tube with a balloon on one end in the breast where the cancer was. The tube comes out of the skin through a small hole. The tube and balloon are placed either during lumpectomy or afterward in a surgeon's office. During each treatment, a machine places a radioactive seed into the center of the balloon for 5 to 10 minutes -- just long enough to deliver the required dose of radiation. After the seed is removed, you may leave the treatment center. A total of 10 treatments are usually given over 5 days. That means 2 treatments per day, about 6 hours apart. When the final treatment is done, the balloon and tube are removed through the small hole in the skin.
3DCRT radiation starts with a planning session (simulation). A special MRI or CAT scan of the breast is done and is used to map out small treatment fields for the area at risk. The type and distribution of radiation is designed to maximize the dose to the area that needs to be treated and avoid or minimize radiation to tissue near the area. The radiation is delivered with a linear accelerator, the same machine used in traditional external radiation, twice a day for 1 week.
Until more results are published, partial-breast irradiation should be considered a promising experimental approach that hasn’t yet been shown to have the same benefits and risks as whole-breast irradiation. We hope that the NSABP B-39/RTOG 0413 study will give doctors more information.
If you've been diagnosed with early-stage breast cancer and lumpectomy followed by radiation therapy will be part of your treatment, ask your doctor about the radiation therapy options that make the most sense for your unique situation. You and your doctor will consider a number of factors, including:
- the characteristics of the cancer (size, location, lymph node involvement)
- your personal preferences (how important is having a shorter total radiation therapy treatment time?)
- the experience level and results of the doctors who will give your radiation therapy
Together you and your doctor will make the best choice for YOU. Visit the Breastcancer.org Radiation Therapy section to learn more about radiation therapy techniques and possible side effects.