APBI associated with more mastectomies, toxicities, complications, compared to traditional radiation

May 1, 2012

Accelerated partial breast irradiation (APBI) brachytherapy, the localized form of radiation therapy growing increasingly popular as a treatment choice for women with early-stage breast cancer, is associated with higher rate of later mastectomy, increased radiation-related toxicities and post-operative complications, compared to traditional whole breast irradiation (WBI), according to researchers from The University of Texas MD Anderson Cancer Center.

The retrospective study, appears in the current issue of JAMA; it was first presented in the CTRC-AACR San Antonio Breast Cancer Symposium. Benjamin Smith, M.D., assistant professor in MD Anderson's Department of Radiation Oncology, is the study's senior author.

"Our study compared the two radiation therapy techniques available to women with early-stage breast cancer. We found that women treated with accelerated partial therapy have a two-fold increased risk for subsequent mastectomy, most likely because of or local complications, as well as an increased risk for post-operative and radiation-related complications," said Smith.

There are numerous types of APBI; the MD Anderson study only looked at the brachytherapy technique, which is a form of radiation treatment involving insertion of a catheter containing a radioactive source to kill that may remain after lumpectomy surgery. A specialized catheter is surgically inserted into the cavity left behind after . APBI brachytherapy is performed a few weeks after a lumpectomy, twice daily over a course of five to seven days.

APBI brachytherapy has grown in popularity over the past decade, since earlier studies showed generally low rates, though most prior studies have not directly compared the outcomes of APBI brachytherapy to traditional radiation therapy, explained Smith.

The first commercially-available single catheter to deliver partial breast irradiation was approved by the FDA in 2002, escalating APBI's use, said Ben Smith.

The MD Anderson study was based on analysis of claim forms filed by 92,735 Medicare beneficiaries nationwide, who were diagnosed with cancer between 2003 and 2007.

"In our study of Medicare patients, we found a consistent increase in APBI brachytherapy, from less than 3.5 percent in 2003 to 13 percent in 2007. It's our guess that this trend has continued," said Smith.

There are benefits to the practicality APBI offers women, noted Smith.

"For whole breast irradiation, the standard treatment time is between five and seven weeks, but studies have shown that some women experience delays or have obstacles completing their course of radiation. Treatment delays and incompletion are known to increase the risk of cancer recurrence in the breast. APBI brachytherapy is attractive because it has the potential to address those issues, because treatment only lasts one week."

However, it's also an invasive procedure with the greater potential for side-effects that are not associated with a non-invasive therapy, such as WBI, noted Smith.

For the retrospective population-based study, the MD Anderson team used Medicare claims to examine the treatment history of 92,735 women age 67 and older diagnosed with early-stage, invasive breast cancer between 2000 and 2007. All of the women were treated with breast-conserving surgery followed by either APBI, delivered by brachytherapy, or traditional radiation therapy.

The researchers analyzed for effectiveness of radiation (defined as the need for a later mastectomy), post-operative complications (infectious and non-infectious), and post-radiation complications (breast pain, fat necrosis and rib fracture).

At five years, the incidence of mastectomy was statistically significantly higher in the APBI brachytherapy-treatment group compared to that of the WBI, 4 percent and 2.2 percent, respectively. APBI brachytherapy was also found to be associated with a higher incidence of acute and late toxicities, compared to those of WBI - infectious complications, 16 and 10 percent, respectively; non-infectious complications, 16 percent and 9 percent, respectively; - and post-radiation complications - five-year incidence of rib fracture, 4.5 and 3.6 percent, respectively; fat necrosis, 8 and 4 percent, respectively; and breast pain, 15 percent and 12 percent, respectively.

The researchers note the study's limits, including that it was not randomized, the relatively-short follow up of patients and limited details regarding tumor characteristics were available.

Given the findings, communication between the patient and her physician is paramount so that a woman with can make an informed, personalized decision, said Thomas A. Buchholz, M.D., professor and head of the Division of at MD Anderson, and an author on the paper.

"This is a very important, well-designed study in a large cohort of patients and provides the first comparison of these two popular radiation techniques after breast-conserving surgery," said Buchholz, also an author on the study. "It's important to note that in both groups, we found a relatively low risk of recurrence. Still, we have a responsibility to discuss potential risks and benefits with our patients, while we await definitive results from randomized trials."

National randomized trials comparing APBI brachytherapy to WBI are ongoing. MD Anderson will continue offering APBI to interested patients in the context of ongoing institutional and multi-institutional clinical protocols, says Buchholz.

Explore further: Study finds side effects, complications, mastectomy more likely after partial breast irradiation

Related Stories

Study finds side effects, complications, mastectomy more likely after partial breast irradiation

December 7, 2011
Accelerated partial breast irradiation (APBI) brachytherapy, the localized form of radiation therapy growing increasingly popular as a treatment choice for women with early-stage breast cancer, is associated with higher rate ...

Advantages and motivations uncertain behind use of brachytherapy for breast cancer radiotherapy

December 16, 2011
Accelerated partial breast irradiation using brachytherapy (APBIb) for the treatment of breast cancer has been rapidly increasing over the last several years in the U.S. as an alternative to standard whole-breast irradiation ...

Recommended for you

Researchers compose guidelines for handling CAR T cell side effects

September 19, 2017
Immune-cell based therapies opening a new frontier for cancer treatment carry unique, potentially lethal side effects that provide a new challenge for oncologists, one addressed by a team led by clinicians at The University ...

Altitude training for cancer-fighting cells

September 18, 2017
Mountain climbers and endurance athletes are not the only ones to benefit from altitude training - that is, learning to perform well under low-oxygen conditions. It turns out that cancer-fighting cells of the immune system ...

Metabolism can be used to subtype hepatoblastoma tumors

September 18, 2017
Looking at cell metabolism instead of histology, EPFL scientists have identified new biomarkers that could help more accurately classify the two main subtypes of hepatoblastoma, a children liver cancer.

A new paradigm for treating transcription factor-driven cancers

September 18, 2017
In the current issue of Proceedings of the National Academy of Sciences, researchers from Nationwide Children's Hospital describe a new paradigm for treating transcription factor-driven cancers. The study focuses on Ewing ...

Scientists find bacteria in pancreatic tumors that metabolize a common drug

September 15, 2017
To the reasons that chemotherapy sometimes does not work, we can now add one more: bacteria. In a study published today in Science, researchers describe findings that certain bacteria can be found inside human pancreatic ...

New technologies combined to identify specific DNA defect underlying a type of cancer

September 15, 2017
(Medical Xpress)—A team of researchers from the Netherlands and the U.K. has developed a technique for studying inherited types of cancers using two relatively new technologies—organoid development and CRISPR/Cas9. In ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.