Women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery “continue to have diagnostic and invasive breast procedures in the conserved breast over an extended period,” according to a study reported in the Journal of the National Cancer Institute. “The estimated 10-year cumulative risk of having at least one diagnostic mammogram after initial DCIS excision was 41.0%,” the investigators reported. The cumulative risk of having at least one invasive procedure was 65.7%.
“The fact that women undergoing BCS are likely to have diagnostic and invasive breast procedures in the conserved breast over an extended period of time is important and needs to be included in discussions about treatment options. The frequency of ongoing diagnostic breast evaluations should be included in discussions about treatment,” the authors concluded.
The study involved 2,948 women with DCIS who were treated with breast-conserving surgery from 1990 to 2001 and followed for up to 10 years at three integrated health-care delivery systems that are part the NCI-funded Cancer Research Network. The mean age of the women was 58.2 years.
“Approximately 42% (n = 1,247) were treated with [breast-conserving surgery] alone, 42% (n = 1,243) with adjuvant radiation, 11% (n = 328) with both adjuvant radiation and tamoxifen, and 4% (n = 130) with tamoxifen alone,” the researchers reported. “Eleven percent (n = 325) of the women had a local recurrence, 173 ipsilateral DCIS, and 152 ipsilateral invasive breast cancer.”
During the 10-year follow-up, 907 women (30.8%) had 1,422 diagnostic mammograms and 1,813 (61.5%) had 2,305 ipsilateral invasive procedures. Diagnostic mammograms occurred in 7.3% of women in the first 6 months and continued at a median annual rate of 4.3%. Ipsilateral invasive procedures occurred in 51.5% of women in the first 6 months and continued at a median annual rate of 3.1%,” the investigators stated.
While breast-conserving surgery “has become the most common treatment for women with DCIS,” according to the authors, “recent data show that mastectomy rates have again begun to increase.” The reasons for this are unclear, but women’s preferences “appear to have a role in the decision for [breast-conserving surgery] vs mastectomy; a recent study found that after women were informed about mortality, treatment, and recurrences after [breast-conserving surgery] and mastectomy, 35% chose mastectomy.”
Women who choose breast-conserving surgery “may be embarking on a more extended journey than anticipated—a journey replete with diagnostic testing that can span many years,” according to an editorial accompanying the article. Women need to understand the implications of screening and treatment options, but informed decision-making is hampered by incomplete information, the editorialists noted. “To reduce the uncertainties surrounding DCIS, we need to learn how to avoid overdiagnosis by calling back fewer women for additional testing after screening mammography; we also need better prognostic biomarkers to minimize overtreatment of lesions that are unlikely to progress to invasive cancer,” they commented.
“In the meantime, we urgently need to assist women in making the best treatment decisions for themselves. Carefully constructed decision aids have been shown to assist patients in understanding medical evidence as well as areas of uncertainty,” the editorialists wrote, and the new data reported should be incorporated into decision aids.
“As the science of DCIS progresses, informed decision-making should remain a motivating priority for clinicians,” the editorialists concluded. “Informed patients feel better about the decision process, and their decisions are more likely to reflect their preferences, values, and concerns. Informed patients are more likely to adhere to treatment and report better self-rated health than less-informed patients.” ■
Nekhlyudov L, et al: J Natl Cancer Inst 104:614-621, 2012.
Elmore JG, Fenton JJ: J Natl Cancer Inst 104:569-571, 2012.