Risks of Breast Brachytherapy

Breast cancer brachytherapy increases risk of later mastectomy

(RxWiki News) After a lumpectomy you can choose - 1) 5-7 weeks of 5-day-a-week radiation treatments, or 2) surgical implanting of a radiation tube (brachytherapy) that stays in place for 5-7 days - and you're done. Easy choice, right? Not so fast.

Women with early breast cancer who choose to have brachytherapy following a lumpectomy are far more likely to need a later mastectomy than women who had so-called whole breast irradiation.

Those who received brachytherapy are also more likely to have more post-surgical complications and radiation toxicity. 

"Ask you doctor the risks and benefits of all medical procedures."

Researchers at The University of Texas MD Anderson Cancer Center looked at patient data of women who had had both types of radiation to kill any remaining cells in the body following surgery. This is the standard of care for women with early stage breast cancer.

Technically known as accelerated partial breast irradiation (APBI) brachytherapy, this technique involves placing a special catheter into the tumor bed after a lumpectomy. It's performed several weeks after surgery twice daily over 5-7 days. 

Senior study author, Benjamin Smith, MD, assistant professor in MD Anderson's Department of Radiation Oncology, is the study's senior author.

"We conducted this study to evaluate outcomes of brachytherapy versus whole breast irradiation in a national cohort of Medicare beneficiaries with invasive breast cancer treated with lumpectomy and radiation therapy," Dr. Smith told dailyRx.

The procedure has gained in popularity following studies that showed generally low cancer recurrence rates. Dr.  Smith points out that these studies never directly compared the procedure with the traditional method in which the whole breast receives radiation.

For this study, researchers analyzed nearly 93,000 Medicare claim forms filed nationwide for people diagnosed with breast cancer between 2003 and 2007.

All participants had a lumpectomy, followed either by brachytherapy or whole breast radiation.

Dr. Smith said, "Although outcomes were very good for both brachytherapy and whole breast irradiation, to our surprise we found that patients treated with brachytherapy were more likely to lose their breast due to mastectomy within five years of diagnosis."

After five years, 4 percent of women who'd received APBI brachytherapy needed a mastectomy, compared with 2.2 percent of women who had received traditional radiotherapy.

Both treatments have benefits and hassles, Dr. Smith noted.

One of the downsides of traditional radiotherapy is the amount of time it takes - 5-7 weeks. Delays or problems completing treatment can affect outcome, Dr. Smith explains. And delays or incomplete treatment can increase risks of the cancer returning.

So the time element alone makes brachytherapy more attractive since treatment time is a week or less.

But in addition to the increased risk of subsequent mastectomy, Dr. Smith said in an email correspondence with dailyRx, "Brachytherapy was also associated with higher risks of post-operative infectious and non-infectious complications and long-term complications such as breast pain and fat necrosis [lumps made of bruised, injured or dead fatty tissue]."

The study found more infectious complications in women who had had APBI brachytherapy  - 16 vs. 10 percent of women who'd received whole breast radiation.

Similar statistically significant increases were seen in other complications  - including rib fracture, infectious complications, post-radiation complications and fat necrosis.  

Dr. Smith concludes, "These data underscore the importance of prospective trials to evaluate brachytherapy in comparison to whole breast irradiation." 

The retrospective study, appears in the May 1 issue of JAMA.

The research was supported by a number of grants from private and governmental sources.

Dr. Smith has a financial relationship with Varian Medical Systems, which presented no conflict of interest in this research.

Reviewed by: 
Review Date: 
May 1, 2012