For patients being treated with radiotherapy after breast-conserving surgery for ductal carcinoma in situ (DCIS), health service areas associated with more use of radiotherapy were correlated with an increased use of mastectomy at the time of a second breast event, even among patients who are eligible for breast conservation, according to a study published in JAMA Oncology.1
Researchers conducted a retrospective analysis of 2679 women through the Surveillance, Epidemiology and End Results (SEER) database who were diagnosed with DCIS between 1990 and 2011, as well as 757 women through the SEER-Medicare database with a DCIS diagnosis between 1991 and 2009.
The observed women had not undergone radiotherapy for DCIS and had experienced a subsequent breast cancer or DCIS diagnosis. Main outcome was mastectomy, compared with breast-conserving surgery at a second breast event, which was defined as DCIS recurrence or new invasive cancer.
It was found that residence in a health service area that was characterized by a greater use of radiotherapy for DCIS increased the likelihood of receiving mastectomy, compared with breast-conserving surgery at a subsequent breast event. This finding included women who had not previously received radiotherapy for DCIS.
RELATED: Gene-expression Prognostic Signatures Guide Adjuvant Chemotherapy of Early-stage Breast Cancer
The adjusted odds ratios for receiving mastectomy were 1.43 in the SEER group and 1.90 in the SEER-Medicare group for women who were residing in a health service area and, comparing greatest radiotherapy use with the least, corresponding with an adjusted increase from 40.8% to 49.6% and 38.6% to 54.5%, respectively.
“This association suggests that physician-related factors are affecting the likelihood of breast preservation,” the authors concluded.
- Punglia RS, Cronin AM, Uno H, et al. Association of regional intensity of ductal carcinoma in situ treatment with likelihood of breast preservation. JAMA Oncol. 21 Jul 2016. doi:10.1001/jamaoncol.2016.2164 [Epub ahead of print]