(ChemotherapyAdvisor) – Breast-conserving treatment is a reasonable option for women with DCIS and results in similar long-term mortality outcomes as mastectomy, according to the researchers from Harvard Medical School and Kaiser Permanente California. The study, entitled “Ten-Year Risk of Diagnostic Mammograms and Invasive Breast Procedures After Breast-Conserving Surgery for DCIS”, was published in the Journal of the National Cancer Institute on April 5.
The study authors identified nearly 3,000 women with DCIS who had undergone BCS between 1990 and 2001, then followed their cases for up to ten years at three integrated health-care delivery systems. The percentages of diagnostic mammograms and ipsilateral invasive procedures following the initial breast excision to treat DCIS were then calculated. Researchers then estimated the ten-year cumulative incidence of these procedures and determined hazard ratios for both types of procedures with Cox regression modeling.
The authors wrote: “The estimated ten-year cumulative risk of having at least one diagnostic mammogram after initial DCIS excision was 41% (95% confidence interval [CI]=38.5% to 43.5%); at least one invasive procedure, 65.7% (95% CI=63.7% to 67.8%); and either event, 76.1% (95% CI=74.1% to 78.1%). Excluding events in the first six months following initial DCIS excision, corresponding risks were 36.4% (95% CI=33.8% to 39%) for diagnostic mammograms, 30.4% (95% CI = 26.9% to 33.8%) for invasive procedures, and 49.5% (95% CI=45.6% to 53.5%) for either event.”
The authors concluded: “Women with DCIS treated with BCS continue to have diagnostic and invasive breast procedures in the conserved breast over an extended period. The frequency of ongoing diagnostic breast evaluations should be included in discussions about treatment.”