Today's blog continues our series on the latest news on brachytherapy for breast cancer with a focus on how patients are selected for brachytherapy. We'll highlight a Journal of the National Cancer Institute study which compared patient selection in practice to the recommendations of the 2009 American Society for Radiation Oncology consensus guidelines, known as ASTRO-G.
Links to the study, guidelines and media reports may be found on the brachytherapy page of our LATESTBreastCancer.com website.
Part 1 of this series provided a brief overview of accelerated partial breast irradiation (APBI) and brachytherapy, including descriptions of the Mammosite, Contura Multi-Lumen Balloon and SAVI Applicator brachytherapy systems.
Part 2 discussed a presentation at the 2011 San Antonio Breast Cancer Symposium on mastectomy rates and side effects associated with brachytherapy.
Today's blog addresses the question of patient eligibility for brachytherapy treatment.
The ASTRO-G consensus guidelines for patient selection
In 2009, the American Society for Radiation Oncology published a consensus statement with guidelines for brachytherapy use. (The link to the statement is dated November 10, 2011 on our website.)
Based upon clinical trial data at the time, the consensus statement defined three patient types - "suitable," "cautionary" and "unsuitable" for brachytherapy treatment.
Patients suitable for brachytherapy would be at least 60 years old, with no BRCA 1/2 mutations, tumors no larger than 2 cm, estrogen-receptor positive, node-negative invasive ductal carcinoma with no DCIS.
Factors which would result in a cautionary status would be patient age between 50 and 59 years old, tumor size between 2.1 and 3 cm, estrogen-receptor negative status, invasive lobular carcinoma, or DCIS less than 3 cm.
Factors which would result in an unsuitable status would be patient age less than 50, BRCA 1/2 mutations, tumor size greater than 3 cm, DCIS greater than 3 cm, node-positive status and use of chemotherapy before surgery (neoadjuvant chemotherapy.)
The Journal of the National Cancer Institute study
A December 16 Journal of the National Cancer Institute study compared the use of brachytherapy in patients from 2000 to 2007 to the recommendations of the 2009 ASTRO-G guidelines. US News and World Report/HealthDay and the Oncology Nurse Advisor covered the study.
The researchers reviewed data of over 138,000 women. In sum, 2.6% were treated with brachytherapy. Brachytherapy use increased from 0.4% in 2000 to 6.6% in 2007.
Of the women treated with brachytherapy, 32% would be classified as suitable under the ASTRO-G guidelines. 29.6% would be considered cautionary and 36.2% would be considered unsuitable.
Considering the entire population of 138,000, 5% of those suitable for brachytherapy were treated with it. 3.4% of patients considered cautionary and 1.6 of those considered unsuitable were treated with brachytherapy. Looking at it another way, 98.4% of patients considered unsuitable were not treated with brachytherapy. Even 95% of those considered suitable did not receive brachytherapy.
Interestingly, the Oncology Nurse Advisor noted that the steepest increase in brachytherapy use was among suitable patients, ranging from 0.7% in 2000 to 11% in 2007.
It should be noted that the ASTRO-G guidelines were not available until two years after the women in the study were treated. It will be interesting to see future studies on patient selection after the guidelines were published.
For more news and research on brachytherapy, please visit the treatment pages of the LATESTBreastCancer.com website. From the home page, click the Treatments tab and search for "brachytherapy" in the box in the top right corner. For news and research on specific brachytherapy options, you may search for "Mammosite," "Contura" or "SAVI." Future blogs will highlight news and research specific to the various treatment options. Please stay tuned.