(HealthDay News) — There were substantial shifts in treatment patterns for ductal carcinoma in situ (DCIS) from 1991 to 2010, with more women opting for lumpectomy and radiation therapy rather than single mastectomy, according to a study published online September 30 in the Journal of the National Cancer Institute.
Mathias Worni, from Duke University Medical Center in Durham, North Carolina, and colleagues used data from the Surveillance, Epidemiology, and End Results (SEER) registry to identify patients diagnosed with DCIS from 1991–2010. Treatment pattern trends were analyzed to determine their impact on disease-specific survival (DSS) and overall survival (OS).
The researchers found that the greatest proportion of the 121,080 patients were treated with lumpectomy and radiation therapy (43%), followed by lumpectomy alone (26.5%) and unilateral (23.8%) or bilateral mastectomy (4.5%), with significant shifts over time. For both mastectomy and lumpectomy, the rate of sentinel lymph node biopsy increased (from 9.7% to 67.1% and from 1.4% to 17.8%, respectively). OS was higher for lumpectomy with radiation (hazard ratio [HR], 0.79) and lower for lumpectomy alone (HR, 1.17), compared with mastectomy. Inverse probability weight-adjusted 10-year DSS was highest in lumpectomy with radiation therapy (98.9%), followed by mastectomy (98.5%) and lumpectomy alone (98.4%).
“When outcomes between locoregional treatment options were compared, we observed greater differences in OS than DSS, likely reflecting both a prevailing patient selection bias as well as clinically negligible differences in breast cancer outcomes between groups,” write the authors.