Breast Cancer Brachytherapy May Be Overused
- Other versus white race: odds ratio=0.51
- Region of treatment: OR=2.60 to 8.62
- More recent year of treatment: OR=20.3
Among “unsuitable” patients, variables associated with APBIb use were:
- Black versus white race: OR=0.77 (P=0.008)
- Other versus white race: OR=0.46 (P<0.001)
- Region of treatment: OR=3.33 to 21.6 (P<0.001)
- More recent year of treatment: OR=12.7 (P<0.001)
In an accompanying commentary, Simona Shaitelman, MD, from MD Anderson Cancer Center in Houston, said the higher rate of APBIb delivery in whites and non-Hispanics, and the lower rate among women in rural areas, was noteworthy.
“It remains to be elucidated whether this [racial] disparity stems from physician bias in offer this treatment versus the racial and cultural preferences of patients,” she wrote.
Brachytherapy treatment
You will have brachytherapy treatments twice a day, 6 hours apart, for 5 days. You may drive yourself to your treatments if you are feeling well and not taking any medicines that keep you from driving. Before your first treatment each day, an x-ray of your breast will be taken. This is done to check the balloon inflation and position. You will be taken to the treatment room and will lie on an x-ray couch. The therapist will connect your catheter to the HDR machine. The radioactive source is stored in the machine.
After that is done, the radiation therapy staff will leave the room. You will be alone in the room during your treatment. Staff will watch you closely on a monitor. You can talk with the staff over an intercom.
During your treatment, the radiation source will come out of the machine and go into your catheter. You need to stay still during this time. You will not feel anything. After the treatment, the therapist will check to make sure the radiation source has returned to the machine. Then you will be taken off the machine. A nurse will help you to an exam room.
The result for women in rural areas was surprising because there is the presumption that patients who live farther from radiation facilities would benefit from accelerated treatment, she added.
The authors acknowledged some limitations of this research. While the results are generalizable to the U.S. population, this analysis did not include key clinical variables, such as BRCA status, margin status, and neoadjuvant chemotherapy. This lack of information may have results in misplacement of patients into the ASTRO guideline categories.
Also, the study did not look at financial incentives that may have driven APBI use. The SEER data was complete through 2007, before two important reimbursement decreases, in 2008 and 2010, for the way radiation is delivered.
This is the third study in 2011 to document an increased utilization of APBIb, Shaitelman pointed out. An examination of data on Medicare beneficiaries documented a rise in brachytherapy use as an alternative to WBI (J Clin Oncol 2011; 29(2): 157-165).
Another SEER-based study found that the proportion of women who underwent APBIb increased from 0.4% in 2000 to 6.8% in 2007 (Cancer 2011; 117(15): 3305-3310).
But the increased use of APBI may be premature in relation to the results of randomized trials that have looked at the equivalency of APBI to WBI, Shaitelman said.
A study presented at the 2011 San Antonio Breast Cancer Symposium found that women had almost double the risk of mastectomy when they received brachytherapy instead of WBI for early breast cancer.
The study was supported by a grant from the Joint Center for Radiation Therapy Foundation.
The study authors and Shaitelman did not list any disclosures or conflicts of interest.
Primary source: Journal of the National Cancer Institute
Source reference: Hattangadi, JA, et al “Accelerated partial breast irradiation using brachytherapy for breast cancer: patterns in utilization and guideline concordance” J Natl Cancer Inst 2012; 104: 29-41.
Additional source: Journal of the National Cancer Institute
Source reference: Shaitelman, S “Sounding a warning bell? Documentation of the increased utilization of accelerated partial breast irradiation” J Natl Cancer Inst 2012; 104: 1-3.
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By Shalmali Pal, Contributing Editor, MedPage Today
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