Predicting Upstaging of DCIS to Invasive Disease: Radiologists's Predictive Performance

Radiology for Ductal Carcinoma In Situ of the Breast: Updates on Invasive Cancer Progression and Active Monitoring

Ductal carcinoma in situ (DCIS) accounts for approximately 30% of new breast cancer diagnoses. However, our understanding of how normal breast tissue evolves into DCIS and invasive cancers remains insufficient. Further, conclusions regarding the mechanisms of disease progression in terms of histopathology, genetics, and radiology are often conflicting and have implications for treatment planning. Moreover, the increase in DCIS diagnoses since the adoption of organized breast cancer screening programs has raised concerns about overdiagnosis and subsequent overtreatment. Active monitoring, a nonsurgical management strategy for DCIS, avoids surgery in favor of close imaging follow-up to de-escalate therapy and provides more treatment options. However, the two major challenges in active monitoring are identifying occult invasive cancer and patients at risk of invasive cancer progression. Subsequently, four prospective active monitoring trials are ongoing to determine the feasibility of active monitoring and refine the patient eligibility criteria and follow-up intervals. Radiologists play a major role in determining eligibility for active monitoring and reviewing surveillance images for disease progression. Trial results published over the next few years would support a new era of multidisciplinary DCIS care.

Patterns of aggressiveness: risk of progression to invasive breast cancer by mammographic features of calcifications in screen-detected ductal carcinoma in situ

BACKGROUND

Mammographic features of calcifications on mammograms showing invasive breast cancer are associated with survival. Less is known about mammographic features and progression to invasive breast cancer among women treated for ductal carcinoma in situ (DCIS).

PURPOSE

To investigate mammographic features of calcifications in screen-detected DCIS in women who later did and did not get diagnosed with invasive breast cancer.

MATERIAL AND METHODS

This registry-based nested case-control study analyzed data from women with screen-detected DCIS in BreastScreen Norway, 1995-2016. Within this cohort of women with DCIS, those who were later diagnosed with invasive breast cancer (cases) were matched (1:2) to women who were not diagnosed with invasive breast cancer (controls) after their DCIS and by the end of 2016. Information on mammographic features were collected by a national radiological review, where screening mammograms were reviewed locally at each of the 16 breast centers in Norway. We used conditional logistic regression analysis to estimate associations between mammographic features of calcifications in the DCIS mammogram and the risk of subsequent invasive breast cancer.

RESULTS

We found a higher risk of invasive breast cancer associated with fine linear branching (casting) morphology (odds ratio 20.0; 95% confidence interval [CI] 2.5-158.9) compared to fine linear or fine pleomorphic morphology. Regional or diffuse distribution showed an odds ratio of 2.8 (95% CI 1.0-8.2) compared to segmental or linear distribution.

CONCLUSION

Mammographic features of calcifications in screen-detected DCIS were of influence on the risk of invasive breast cancer. Unfavorable characteristics of DCIS were fine linear branching morphology, and regional or diffuse distribution.

Is conservative management of ductal carcinoma in situ risky?

Nonsurgical management of ductal carcinoma in situ is controversial and little is known about the long-term consequences of this approach. In this study, we aimed to determine the risk of (a) upstaging to invasive carcinoma at excision and (b) ipsilateral breast cancer events in patients who might have been eligible for nonsurgical management of DCIS trials. Data from women aged 20 years or older with a biopsy diagnosis of DCIS between January 1, 2010 to December 31, 2014 were collated. The women underwent biopsy and surgical resection (lumpectomy or mastectomy) and were treated with radiation or endocrine therapy as per treating physicians’ choice. The development of ipsilateral breast cancer events (IBEs) was analyzed in patients with at least 5 years of follow-up after standard of care therapy for DCIS. Subset-analysis was undertaken to identify the incidence of IBEs in patients eligible for nonsurgical management trials. The study population consisted of 378 patients with matched cases of biopsy and surgical excision. The overall upstaging rate to IBC was 14.3 and 12.9% for COMET, 8.8% for LORIS, and 10.7% for LORD trial “eligible” patients. At 5 years of follow-up, ~11.5% of overall and trial eligible patients developed IBEs of which approximately half were invasive IBEs. In conclusion, women with DCIS who would have been eligible for nonsurgical management trials have a significantly high risk of developing ipsilateral breast events within 5 years of diagnosis. Better selection criteria are needed to identify DCIS patients who are at very low risk for the development of IBC.

Updates on treating ductal carcinoma in situ: what's to know in 2021

PURPOSE OF REVIEW

Ductal carcinoma in situ (DCIS) is a noninvasive stage of disease but understood to be a nonobligate precursor to invasive breast cancer. As such, women with DCIS are routinely recommended for standard breast cancer treatment to prevent progression to invasive disease. DCIS, however, represents a heterogeneous group of lesions that differs in its biologic behavior and risk of progression. Thus, optimal treatment is unclear. This review presents the clinical trials evaluating the de-escalation of therapy, attempts at risk stratification, and future directions in the management of this disease.

RECENT FINDINGS

The de-escalation of therapy for patients with DCIS is being actively explored. Although no group of patients based on clinicopathologic features has yet been identified as suitable for omission of therapy, molecular tests appear better able to stratify patients at low risk for whom omission of radiation may be considered. Trials considering omission of surgery are ongoing, and the use of Herceptin and vaccine therapy are also being explored.

SUMMARY

The current review provides a centralized summary enabling the clinician to better understand the complexity of DCIS and the controversies over the optimal management of this disease. It highlights the need for better risk stratification to individualize patient care.

VIDEO ABSTRACT

http://links.lww.com/COOG/A77.

Mixed-Methods Study to Predict Upstaging of DCIS to Invasive Disease on Mammography

BACKGROUND. The incidence of ductal carcinoma in situ (DCIS) has steadily increased, as have concerns regarding overtreatment. Active surveillance is a novel treatment strategy that avoids surgical excision, but identifying patients with occult invasive disease who should be excluded from active surveillance is challenging. Radiologists are not typically expected to predict the upstaging of DCIS to invasive disease, though they might be trained to perform this task. OBJECTIVE. The purpose of this study was to determine whether a mixed-methods two-stage observer study can improve radiologists' ability to predict upstaging of DCIS to invasive disease on mammography. METHODS. All cases of DCIS calcifications that underwent stereotactic biopsy between 2010 and 2015 were identified. Two cohorts were randomly generated, each containing 150 cases (120 pure DCIS cases and 30 DCIS cases upstaged to invasive disease at surgery). Nine breast radiologists reviewed the mammograms in the first cohort in a blinded fashion and scored the probability of upstaging to invasive disease. The radiologists then reviewed the cases and results collectively in a focus group to develop consensus criteria that could improve their ability to predict upstaging. The radiologists reviewed the mammograms from the second cohort in a blinded fashion and again scored the probability of upstaging. Statistical analysis compared the performances between rounds 1 and 2. RESULTS. The mean AUC for reader performance in predicting upstaging in round 1 was 0.623 (range, 0.514-0.684). In the focus group, radiologists agreed that upstaging was better predicted when an associated mass, asymmetry, or architectural distortion was present; when densely packed calcifications extended over a larger area; and when the most suspicious features were focused on rather than the most common features. Additionally, radiologists agreed that BI-RADS descriptors do not adequately characterize risk of invasion, and that microinvasive disease and smaller areas of DCIS will have poor prediction estimates. Reader performance significantly improved in round 2 (mean AUC, 0.765; range, 0.617-0.852; p = .045). CONCLUSION. A mixed-methods two-stage observer study identified factors that helped radiologists significantly improve their ability to predict upstaging of DCIS to invasive disease. CLINICAL IMPACT. Breast radiologists can be trained to better predict upstaging of DCIS to invasive disease, which may facilitate discussions with patients and referring providers.