Research shows that at least 3 out of 4 women (75%) with DCIS that is not treated will not get a future invasive breast cancer.
A total of 1286 DCIS patients who did not undergo locoregional therapy were identified. Median age at diagnosis was 60 years (inter-quartile range = 51–74 years), with median follow-up of 5.5 years.
Among patients with tumor grade I/II, the 10-year net risk of ipsilateral invasive breast cancer was 12.2% (95% confidence interval [CI] = 8.6% to 17.1%) compared with 17.6% (95% CI = 12.1% to 25.2%) among patients with tumor grade III (n = 244) and 10.1% (95% CI = 7.4% to 13.8%) among patients with unknown grade (n = 495).
Among all patients, the 10-year cumulative incidences of ipsilateral invasive cancer, contralateral breast cancer, and all-cause mortality were 10.5% (95% CI = 8.5% to 12.4%), 3.9% (95% CI = 2.6% to 5.2%), and 24.1% (95% CI = 21.2% to 26.9%), respectively.
“Despite limited data, our findings suggest that DCIS patients without locoregional treatment have a limited risk of invasive progression. Although the cohort is not representative of the general population of patients diagnosed with DCIS, the findings suggest that there may be overtreatment, especially among older patients and patients with elevated comorbidities.”
“A recent evaluation of data from the SEER registry of women diagnosed with DCIS from 1992-2014 who did not undergo surgery at the time of diagnosis indicates that the rate of invasive progression is highly variable between individuals and that the 10-year net risk of ipsilateral invasive breast cancer ranged from 15%-28%, depending on age at diagnosis and histologic features.”45
Comparing Treatment Options for Women with Low-Risk Ductal Carcinoma In Situ (DCIS) — The COMET Study
“Only 20–30 percent of DCIS cases turn into invasive cancer, which is cancer that spreads and causes illness.”
Surgical Upstaging Rates for Vacuum Assisted Biopsy Proven DCIS: Implications for Active Surveillance Trials
“DCIS upstaging rates in women eligible for active surveillance trials are low (6–10%), and in this series, all those with invasive disease were early-stage, node-negative. The careful patient selection for DCIS active surveillance trials has a low risk of missing occult invasive cancer and additional studies will determine clinical outcomes.”
“For low-grade DCIS, the weighted 10-year breast cancer–specific survival of the nonsurgery group was 98.8% and that of the surgery group was 98.6%.”
“Surgery for DCIS has remained largely unchanged since the 1970s, and mastectomy is now performed more often than is seen with invasive cancer. It is 40 years since the inception of the first breast screening programs, and it is time to question the appropriateness and the outcomes of these management policies for screen-detected DCIS.”
Low-risk ductal carcinoma in situ (DCIS) lesions often do not progress to invasive breast cancer during the patient’s lifetime. Therefore, active surveillance (active monitoring) without surgery as a management strategy for low-risk DCIS is being evaluated in three Clinical Trials, called the COMET (USA)- LORIS (UK)- and LORD (The Netherlands/EU)-trial.