Purpose: We analyzed the risk of second malignancies developing in patients with ductal carcinoma in situ (DCIS) undergoing surgery and radiotherapy (S+RT) vs. surgery alone. Methods and Materials: The S+RT cohort consisted of 256 women treated with breast-conserving therapy at William Beaumont Hospital. The surgery alone cohort consisted of 2,788 women with DCIS in the regional Surveillance, Epidemiology, and End Results database treated during the same time period. A matched-pair analysis was performed in which each S+RT patient was randomly matched with 8 surgery alone patients (total of 2,048 patients). Matching criteria included age ± 2 years. The rates of second malignancies were analyzed overall and as contralateral breast vs. non-breast cancers and by organ system. Results: Median follow-up was 13.7 years for the S+RT cohort and 13.3 years for the surgery alone cohort. The overall 10-/15-year rates of second malignancies among the S+RT and surgery alone cohorts were 14.2%/24.2% and 16.4%/22.6%, respectively (p = 0.668). The 15-year second contralateral breast cancer rate was 14.2% in the S+RT cohort and 10.3% in the surgery alone cohort (p = 0.439). The 15-year risk of a second non-breast malignancy was 14.2% for the S+RT cohort and 13.4% for the surgery alone cohort (p = 0.660). When analyzed by organ system, the 10- and 15-year rates of second malignancies did not differ between the S+RT and surgery alone cohorts for pulmonary, gastrointestinal, central nervous system, gynecologic, genitourinary, lymphoid, sarcomatoid, head and neck, or unknown primary tumors. Conclusions: Compared with surgery alone, S+RT is not associated with an overall increased risk of second malignancies in women with DCIS.
|Number of pages||8|
|Journal||International Journal of Radiation Oncology Biology Physics|
|State||Published - Dec 1 2011|
- Breast cancer
- Breast-conserving therapy
- Ductal carcinoma in situ
- Second malignancies