Do LORIS Trial Eligibility Criteria Identify a Ductal Carcinoma In Situ Patient Population at Low Risk of Upgrade to Invasive Carcinoma?

Evolving Treatment Paradigms for Low-Risk Ductal Carcinoma In Situ: Imaging Needs

Ductal carcinoma in situ (DCIS) is a nonobligate precursor to invasive cancer that classically presents as asymptomatic calcifications on screening mammography. The increase in DCIS diagnoses with organized screening programs has raised concerns about overdiagnosis, while a patientcentric push for more personalized care has increased awareness about DCIS overtreatment. The standard of care for most new DCIS diagnoses is surgical excision, but nonsurgical management via active monitoring is gaining attention, and multiple clinical trials are ongoing. Imaging, along with demographic and pathologic information, is a critical component of active monitoring efforts. Commonly used imaging modalities including mammography, ultrasound, and MRI, as well as newer modalities such as contrast-enhanced mammography and dedicated breast PET, can provide prognostic information to risk stratify patients for DCIS active monitoring eligibility. Furthermore, radiologists will be responsible for closely surveilling patients on active monitoring and identifying if invasive progression occurs. Active monitoring is a paradigm shift for DCIS care, but the success or failure will rely heavily on the interpretations and guidance of radiologists.

Presurgical Oral Tamoxifen vs Transdermal 4-Hydroxytamoxifen in Women With Ductal Carcinoma In Situ: A Randomized Clinical Trial

Importance

Oral tamoxifen citrate benefits women with ductal carcinoma in situ (DCIS), but concern about toxic effects has limited acceptance. Previous pilot studies have suggested transdermal 4-hydroxytamoxifen gel has equivalent antiproliferative efficacy to oral tamoxifen, with low systemic exposure.

Objective

To demonstrate that 4-hydroxytamoxifen gel applied to the breast skin is noninferior to oral tamoxifen in its antiproliferative effect in DCIS lesions.

Design, Setting, and Participants

This randomized, double-blind, phase 2 preoperative window trial was performed at multicenter breast surgery referral practices from May 31, 2017, to January 27, 2021. Among 408 women with estrogen receptor-positive DCIS who were approached, 120 consented and 100 initiated study treatment. The most common reasons for nonparticipation were surgical delay, disinterest in research, and concerns about toxic effects. Data were analyzed from January 26, 2021, to October 5, 2022.

Intervention

Random assignment to oral tamoxifen citrate, 20 mg/d, and gel placebo or 4-hydroxytamoxifen gel, 2 mg/d per breast, and oral placebo, for 4 to 10 weeks, followed by DCIS resection.

Main Outcomes and Measures

The primary end point was absolute change in DCIS Ki-67 labeling index (Ki67-LI). Secondary end points included 12-gene DCIS Score, breast tissue tamoxifen metabolite concentrations, tamoxifen-responsive plasma protein levels, and patient-reported symptoms. Noninferiority of Ki67-LI reduction by 4-hydroxytamoxifen gel was tested using analysis of covariance; within- and between-arm comparisons were performed with paired t tests for mean values or the Wilcoxon rank sum test for medians.

Results

Of 90 participants completing treatment (mean [SD] age, 55 [11] years; 8 [8.9%] Asian, 16 [17.8%] Black, 8 [8.9%] Latina, and 53 [58.9%] White), 15 lacked residual DCIS in the surgical sample, leaving 75 evaluable for the primary end point analysis (40 in the oral tamoxifen group and 35 in the 4-hydroxytamoxifen gel group). Posttreatment Ki67-LI was 3.3% higher (80% CI, 2.1%-4.6%) in the 4-hydroxytamoxifen gel group compared with the oral tamoxifen group, exceeding the noninferiority margin (2.6%). The DCIS Score decreased more with oral tamoxifen treatment (-16 [95% CI, -22 to -9.4]) than with 4-hydroxytamoxifen gel (-1.8 [95% CI, -5.8 to 2.3]). The median 4-hydroxytamoxifen concentrations deep in the breast were nonsignificantly higher in the oral tamoxifen group (5.7 [IQR, 4.0-7.9] vs 3.8 [IQR, 1.3-7.9] ng/g), whereas endoxifen was abundant in the oral tamoxifen group and minimal in the 4-hydroxytamoxifen gel group (median, 13.0 [IQR, 8.9-20.6] vs 0.3 [IQR, 0-0.3] ng/g; P < .001). Oral tamoxifen caused expected adverse changes in plasma protein levels and vasomotor symptoms, with minimal changes in the transdermal group.

Conclusions and Relevance

In this randomized clinical trial, antiproliferative noninferiority of 4-hydroxytamoxifen gel to oral tamoxifen was not confirmed, potentially owing to endoxifen exposure differences. New transdermal approaches must deliver higher drug quantities and/or include the most potent metabolites.

Trial Registration

ClinicalTrials.gov Identifier: NCT02993159.

Active Surveillance for Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ

Atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) are relatively common breast lesions on the same spectrum of disease. Atypical ductal hyperblasia is a nonmalignant, high-risk lesion, and DCIS is a noninvasive malignancy. While a benefit of screening mammography is early cancer detection, it also leads to increased biopsy diagnosis of noninvasive lesions. Previously, treatment guidelines for both entities included surgical excision because of the risk of upgrade to invasive cancer after surgery and risk of progression to invasive cancer for DCIS. However, this universal management approach is not optimal for all patients because most lesions are not upgraded after surgery. Furthermore, some DCIS lesions do not progress to clinically significant invasive cancer. Overtreatment of high-risk lesions and DCIS is considered a burden on patients and clinicians and is a strain on the health care system. Extensive research has identified many potential histologic, clinical, and imaging factors that may predict ADH and DCIS upgrade and thereby help clinicians select which patients should undergo surgery and which may be appropriate for active surveillance (AS) with imaging. Additionally, multiple clinical trials are currently underway to evaluate whether AS for DCIS is feasible for a select group of patients. Recent advances in MRI, artificial intelligence, and molecular markers may also have an important role to play in stratifying patients and delineating best management guidelines. This review article discusses the available evidence regarding the feasibility and limitations of AS for ADH and DCIS, as well as recent advances in patient risk stratification.

Prediction of the histologic upgrade of ductal carcinoma in situ using a combined radiomics and machine learning approach based on breast dynamic contrast-enhanced magnetic resonance imaging

Objective

To investigate whether support vector machine (SVM) trained with radiomics features based on breast magnetic resonance imaging (MRI) could predict the upgrade of ductal carcinoma in situ (DCIS) diagnosed by core needle biopsy (CNB) after surgical excision.

Materials and methods

This retrospective study included a total of 349 lesions from 346 female patients (mean age, 54 years) diagnosed with DCIS by CNB between January 2011 and December 2017. Based on histological confirmation after surgery, the patients were divided into pure (n = 198, 56.7%) and upgraded DCIS (n = 151, 43.3%). The entire dataset was randomly split to training (80%) and test sets (20%). Radiomics features were extracted from the intratumor region-of-interest, which was semi-automatically drawn by two radiologists, based on the first subtraction images from dynamic contrast-enhanced T1-weighted MRI. A least absolute shrinkage and selection operator (LASSO) was used for feature selection. A 4-fold cross validation was applied to the training set to determine the combination of features used to train SVM for classification between pure and upgraded DCIS. Sensitivity, specificity, accuracy, and area under the receiver-operating characteristic curve (AUC) were calculated to evaluate the model performance using the hold-out test set.

Results

The model trained with 9 features (Energy, Skewness, Surface Area to Volume ratio, Gray Level Non Uniformity, Kurtosis, Dependence Variance, Maximum 2D diameter Column, Sphericity, and Large Area Emphasis) demonstrated the highest 4-fold mean validation accuracy and AUC of 0.724 (95% CI, 0.619–0.829) and 0.742 (0.623–0.860), respectively. Sensitivity, specificity, accuracy, and AUC using the test set were 0.733 (0.575–0.892) and 0.7 (0.558–0.842), 0.714 (0.608–0.820) and 0.767 (0.651–0.882), respectively.

Conclusion

Our study suggested that the combined radiomics and machine learning approach based on preoperative breast MRI may provide an assisting tool to predict the histologic upgrade of DCIS.

Incidence of Occult Breast Cancer in Carriers of BRCA1/2 or Other High-Penetrance Pathogenic Variants Undergoing Prophylactic Mastectomy: When is Sentinel Lymph Node Biopsy Indicated?

BACKGROUND

This study sought to determine the likelihood of occult malignancy during risk-reducing mastectomy in high-penetrance pathogenic variant carriers to help refine axillary staging recommendations.

METHODS

The authors performed a retrospective cohort study analyzing all female carriers of pathogenic variants in BRCA1/2, PALB2 or other genes who underwent prophylactic surgery at their institution between 2006 and 2021. Occult breast cancer was defined as the unanticipated presence of in situ or invasive malignancy on pathologic evaluation of prophylactic mastectomy specimens.

RESULTS

Of 523 women, 243 carriers met the inclusion criteria for the study including 124 BRCA1 (51.0%), 108 BRCA2 (44.4%), and 11 PALB2, TP53, CDH1, or PTEN (4.6%) carriers. The median age was 44 years (interquartile range, 37-52 years). Overall, 128 women (52.7%) underwent bilateral prophylactic mastectomies, and 115 (47.3%) underwent contralateral prophylactic mastectomy. In the 371 mastectomies performed, 16 (4.3%) occult malignancies were diagnosed. Most of the occult malignancies were ductal carcinoma in situ (13 mastectomies, 3.5%), whereas 3 mastectomies (0.8%) contained invasive breast cancer. If Breast Imaging Reporting and Data System (BIRADS) 1-2 or BIRADS 3 findings were reported on preoperative magnetic resonance imaging (MRI), the rate of occult malignancy decreased to 3.0 and 2.8%, respectively, per mastectomy. The patient-level factors associated with a likelihood of occult breast cancer greater than 10% included a history of prior breast cancer, age exceeding 60 years, and BIRADS 4 findings on preoperative imaging.

CONCLUSIONS

Occult invasive malignancy was detected in less than 1% of the risk-reducing mastectomies performed for women with BRCA1/2 or PALB2 pathogenic variants. Sentinel lymph node biopsy can be safely avoided when BIRADS 1-3 findings are reported on preoperative MRI.

Addressing the problem of overtreatment in breast cancer

INTRODUCTION

As breast cancer treatment options have multiplied and biologic diversity within breast cancer has been recognized, the use of the same treatment strategies for patients with early-stage and favorable disease, and for those with biologically aggressive disease, has been questioned. In addition, as patient-reported outcome measures have called attention to the morbidity of many common treatments, and as the cost of breast cancer care has continued to increase, reduction in the overtreatment of breast cancer has assumed increasing importance.

AREAS COVERED

Here we review selected aspects of surgery, radiation oncology, and medical oncology for which scientific evidence supports de-escalation for invasive carcinoma and ductal carcinoma in situ, and assess strategies to address overtreatment.

EXPERT OPINION

The problems of breast cancer overtreatment we face today are based on improved understanding of the biology of breast cancer and abandonment of the 'one-size-fits-all' approach. As breast cancer care becomes increasingly complex, and as our knowledge base continues to increase exponentially, these problems will only be magnified in the future. To continue progress, the move must be made from advocating the maximum-tolerated treatment to advocating the minimum-effective one.

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.

Ductal Carcinoma in Situ: Molecular Changes Accompanying Disease Progression

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive ductal carcinoma (IDC), whereby if left untreated, approximately 12% of patients develop invasive disease. The current standard of care is surgical removal of the lesion, to prevent potential progression, and radiotherapy to reduce risk of recurrence. There is substantial overtreatment of DCIS patients, considering not all DCIS lesions progress to invasive disease. Hence, there is a critical imperative to better predict which DCIS lesions are destined for poor outcome and which are not, allowing for tailored treatment. Active surveillance is currently being trialed as an alternative management practice, but this approach relies on accurately identifying cases that are at low risk of progression to invasive disease. Two DCIS-specific genomic profiling assays that attempt to distinguish low and high-risk patients have emerged, but imperfections in risk stratification coupled with a high price tag warrant the continued search for more robust and accessible prognostic biomarkers. This search has largely turned researchers toward the tumor microenvironment. Recent evidence suggests that a spectrum of cell types within the DCIS microenvironment are genetically and phenotypically altered compared to normal tissue and play critical roles in disease progression. Uncovering the molecular mechanisms contributing to DCIS progression has provided optimism for the search for well-validated prognostic biomarkers that can accurately predict the risk for a patient developing IDC. The discovery of such markers would modernize DCIS management and allow tailored treatment plans. This review will summarize the current literature regarding DCIS diagnosis, treatment, and pathology.

Atypical Ductal Hyperplasia-Ductal Carcinoma In Situ Spectrum: Diagnostic Considerations and Treatment Impact in the Era of Deescalation

As the first node in treatment algorithms for breast disease, pathologists have the potential to play a critical role in refining appropriate therapy for lesions in the atypical ducal hyperplasia-ductal carcinoma in situ (ADH-DCIS) spectrum by conservatively approaching diagnosis of lesions limited in size on core needle biopsy. Appropriate efforts to downgrade the diagnosis of lesions at the borderline of ADH and DCIS will certainly lead to more breast conservation and avoid the common morbidities of mastectomy, sentinel node biopsy, and radiation therapy. Whether results of clinical trials of active surveillance will successfully identify a subset of women who may successfully forgo even limited breast-conserving surgery is eagerly anticipated. Given the increasing concern that a significant number of women with DCIS are overtreated, identification of patients at very low risk for progression who may forgo surgery and radiation therapy safely is of significant interest.

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.

Preneoplastic Low-Risk Mammary Ductal Lesions (Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ Spectrum): Current Status and Future Directions

Intraepithelial mammary ductal neoplasia is a spectrum of disease that varies from atypical ductal hyperplasia (ADH), low-grade (LG), intermediate-grade (IG), to high-grade (HG) ductal carcinoma in situ (DCIS). While ADH has the lowest prognostic significance, HG-DCIS carries the highest risk. Due to widely used screening mammography, the number of intraepithelial mammary ductal neoplastic lesions has increased. The consequence of this practice is the increase in the number of patients who are overdiagnosed and, therefore, overtreated. The active surveillance (AS) trials are initiated to separate lesions that require active treatment from those that can be safely monitored and only be treated when they develop a change in the clinical/radiologic characteristics. At the same time, the natural history of these lesions can be evaluated. This review aims to evaluate ADH/DCIS as a spectrum of intraductal neoplastic disease (risk and histomorphology); examine the controversies of distinguishing ADH vs. DCIS and the grading of DCIS; review the upgrading for both ADH and DCIS with emphasis on the variation of methods of detection and the definitions of upgrading; and evaluate the impact of all these variables on the AS trials.

Ductal Carcinoma in Situ: State-of-the-Art Review

Ductal carcinoma in situ (DCIS) is a nonobligate precursor of invasive cancer, and its detection, diagnosis, and management are controversial. DCIS incidence grew with the expansion of screening mammography programs in the 1980s and 1990s, and DCIS is viewed as a major driver of overdiagnosis and overtreatment. For pathologists, the diagnosis and classification of DCIS is challenging due to undersampling and interobserver variability. Understanding the progression from normal breast tissue to DCIS and, ultimately, to invasive cancer is limited by a paucity of natural history data with multiple proposed evolutionary models of DCIS initiation and progression. Although radiologists are familiar with the classic presentation of DCIS as asymptomatic calcifications at mammography, the expanded pool of modalities, advanced imaging techniques, and image analytics have identified multiple potential biomarkers of histopathologic characteristics and prognosis. Finally, there is growing interest in the nonsurgical management of DCIS, including active surveillance, to reduce overtreatment and provide patients with more personalized management options. However, current biomarkers are not adept at enabling identification of occult invasive disease at biopsy or accurately predicting the risk of progression to invasive disease. Several active surveillance trials are ongoing and are expected to better identify women with low-risk DCIS who may avoid surgery.

Advances and controversies in management of breast ductal carcinoma in situ (DCIS)

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer. It accounts for 25% of all breast cancers diagnosed, as a result of the expansion of breast cancer screening and is associated with a high survival rate. DCIS is particularly clinically challenging, due to its heterogeneous pathological and biological traits and its management is continually evolving towards more personalized and less aggressive therapies. This article suggests evidence-based guidelines for proper DCIS clinical management, which should be discussed within a multidisciplinary team in order to propose the most suitable approach in clinical practice, taking into account recent scientific studies. Here we include updated multidisciplinary treatment protocols and techniques in accordance with the most recent contributions published on this topic in the peer-reviewed medical literature, and we outline future perspectives.

Low-risk DCIS. What is it? Observe or excise?

The issue of overdiagnosis and overtreatment of lesions detected by breast screening mammography has been debated in both international media and the scientific literature. A proportion of cancers detected by breast screening would never have presented symptomatically or caused harm during the patient's lifetime. The most likely (but not the only) entity which may represent those overdiagnosed and overtreated is low-grade ductal carcinoma in situ (DCIS). In this article, we address what is understood regarding the natural history of DCIS and the diagnosis and prognosis of low-grade DCIS. However, low cytonuclear grade disease may not be the totality of DCIS that can be considered of low clinical risk and we outline the issues regarding active surveillance vs excision of low-risk DCIS and the clinical trials exploring this approach.

Axillary evaluation in ductal cancer in situ of the breast: challenging the diagnostic accuracy of clinical practice guidelines

BACKGROUND

Staging of the axilla is not routine in ductal cancer in situ (DCIS) although invasive cancer is observed in 20-25 per cent of patients at final pathology. Upfront sentinel lymph node dissection (SLND) is advocated in clinical practice guidelines in certain situations. These include expected challenges in subsequent SLN detection and when the risk for invasion is high. Clinical practice guidelines are, however, inconsistent and lead to considerable practice variability.

METHODS

Clinical practice guidelines for upfront SLND in DCIS were identified and applied to patients included in the prospective SentiNot study. These patients were evaluated by six independent, blinded raters. Agreement statistics were performed to assess agreement and concordance. Receiver operating characteristic curves were constructed, to assess guideline accuracy in identifying patients with underlying invasion.

RESULTS

Eight guidelines with relevant recommendations were identified. Interobserver agreement varied greatly (kappa: 0.23-0.9) and the interpretation as to whether SLND should be performed ranged from 40-90 per cent and with varying concordance (32-88 per cent). The diagnostic accuracy was low with area under the curve ranging from 0.45 to 0.55. Fifty to 90 per cent of patients with pure DCIS would undergo unnecessary SLNB, whereas 10-50 per cent of patients with invasion were not identified as 'high risk'. Agreement across guidelines was low (kappa = 0.24), meaning that different patients had a similar risk of being treated inaccurately.

CONCLUSION

Available guidelines are inaccurate in identifying patients with DCIS who would benefit from upfront SLNB. Guideline refinement with detailed preoperative work-up and novel techniques for SLND identification could address this challenge and avoid overtreatment.

Surgical upstaging rates in patients meeting the eligibility for active surveillance trials

PURPOSE

Four clinical active surveillance trials including LORIS, COMET, LORD and LORETTA, are being conducted to assess whether women with low-risk ductal carcinoma in situ can safely avoid surgery. The present study aimed to determine the rate of upstaging to invasive cancer among patients with a preoperative diagnosis of ductal carcinoma in situ and to evaluate the incidence of upstaging in patients meeting the eligibility criteria for four active surveillance clinical trials.

METHODS

The present study initially enrolled 180 patients with 183 calcifications who received the diagnosis of ductal carcinoma in situ by biopsy. Patients were classified as eligible for four clinical trials according to the respective inclusion criteria.

RESULTS

In total, 152 patients with 155 calcifications were analyzed. Of these, 32 (21%) were upstaged to invasive disease based on the final pathological analysis of surgical specimens. Of the 152 patients, 53 (35%), 90 (59%), 24 (16%) and 34 (22%) met the eligibility criteria for the LORIS, COMET, LORD and LORETTA trial, respectively. Among patients with low-risk ductal carcinoma in situ, 10 (19%), 14 (16%), 6 (25%) and 4 (12%) patients were upstaged to invasive disease in LORIS, COMET, LORD and LORETTA, respectively. The upstaging to pT1b or higher rates were 2% (1/53), 3% (3/90), 0% (0/24) and 3% (1/34) in LORIS, COMET, LORD and LORETTA, respectively.

CONCLUSIONS

The upstaging rate in patients eligible for the clinical active surveillance trials was 12-25%. Although the rate of upstaging to pT1b or higher was low, further studies are required to determine the rates of upstaging to invasive cancer and the risk factors among patients with low-risk ductal carcinoma in situ.

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.

Genomic profiling reveals heterogeneous populations of ductal carcinoma in situ of the breast

In a substantial number of patients, ductal carcinoma in situ (DCIS) of the breast will never progress to invasive ductal carcinoma, and these patients are often overtreated under the current clinical criteria. Although various candidate markers are available, relevant markers for delineating risk categories have not yet been established. In this study, we analyzed the clinical characteristics of 431 patients with DCIS and performed whole-exome sequencing analysis in a 21-patient discovery cohort and targeted deep sequencing analysis in a 72-patient validation cohort. We determined that age <45 years, HER2 amplification, and GATA3 mutation are possible indicators of relapse. PIK3CA mutation negativity and PgR negativity were also suggested to be risk factors. Spatial transcriptome analysis further revealed that GATA3 dysfunction upregulates epithelial-to-mesenchymal transition and angiogenesis, followed by PgR downregulation. These results reveal the existence of heterogeneous cell populations in DCIS and provide predictive markers for classifying DCIS and optimizing treatment.

Satoi Nagasawa and Yuta Kuze et al. report a multi-omic analysis of ductal carcinoma in situ (DCIS) of the breast, including whole-exome, single-cell, and spatial transcriptome sequencing. They find that for patients under 45 years of age, HER2 amplification and GATA3 mutation are associated with higher risk of relapse, suggesting they could be used as predictive markers when deciding on a treatment course.

Nuclear grade and comedo necrosis of ductal carcinoma in situ as histopathological eligible criteria for the Japan Clinical Oncology Group 1505 trial: an interobserver agreement study

OBJECTIVE

The Japan Clinical Oncology Group 1505 trial is a single-arm multicentre prospective study that examined the possibility of non-surgical follow-up with endocrine therapy for patients with low-grade ductal carcinoma in situ. In that study, the eligible criteria included histopathological findings comprising low to intermediate nuclear grade and absence of comedo necrosis, and cases were entered according to the local histopathological diagnosis. Nuclear grade is largely based on the Consensus Conference criteria (1997), whereas comedo necrosis is judged according to the Rosen's criteria (2017). The purpose of this study was to standardize and examine the interobserver agreement levels of these histopathological criteria amongst the participating pathologists.

METHODS

We held slide conferences, where photomicrographs of haematoxylin-eosin-stained slides from 68 patients with ductal carcinoma in situ were presented using PowerPoint. The nuclear grade and comedo necrosis statuses individually judged by the pathologists were analysed using κ statistics.

RESULTS

In the first and second sessions, where 22 cases each were presented, the interobserver agreement levels of nuclear grade whether low/intermediate grade or high grade were moderate amongst 29 and 24 participating pathologists, respectively (κ = 0.595 and 0.519, respectively). In the third session where 24 cases were presented, interobserver agreement levels of comedo necrosis or non-comedo necrosis were substantial amongst 25 participating pathologists (κ = 0.753).

CONCLUSION

Although the concordance rates in nuclear grade or comedo necrosis were not high in a few of the cases, we believe that these results could provide a rationale for employing the present criteria of nuclear grade and comedo necrosis in the clinical study of ductal carcinoma in situ.

Ductal Carcinoma In Situ and Progression to Invasive Cancer: A Review of the Evidence

Ductal carcinoma in situ (DCIS), breast cancer confined to the milk ducts, is a heterogeneous entity. The question of how and when a case of DCIS will extend beyond the ducts to become invasive breast cancer has implications for both patient prognosis and optimal treatment approaches. The natural history of DCIS has been explored through a variety of methods, from mouse models to biopsy specimen reviews to population-based screening data to modeling studies. This article will review the available evidence regarding progression pathways and will also summarize current trials designed to assess DCIS progression.

Complete Removal of the Lesion as a Guidance in the Management of Patients with Breast Ductal Carcinoma In Situ

Simple Summary

A diagnosis of ductal carcinoma in situ, made on biopsy, is often followed by surgery or radiotherapy because of the risk of an upgrading disease upon subsequent surgical specimens, finding invasive carcinoma. In order to select which patients can be spared overtreatments and alternatively followed with active surveillance, we retrospectively reviewed 2173 vacuum assisted breast biopsies. Our goal was to demonstrate if complete removal of the lesion by biopsy, documented by mammograms, can be a valid criterion to select the patients that can be spared further treatments. The results of our study demonstrate a significant lower upgrading rate of disease when the lesion is completely removed. Thus, performing a mammogram to document the absence of residual lesion following vacuum-assisted breast biopsy (VABB) allows us to reduce overtreatments and to select which patients can be followed with an active surveillance, sparing unjustified public health costs.

Abstract

Background: Considering highly selected patients with ductal carcinoma in situ (DCIS), active surveillance is a valid alternative to surgery. Our study aimed to show the reliability of post-biopsy complete lesion removal, documented by mammogram, as additional criterion to select these patients. Methods: A total of 2173 vacuum-assisted breast biopsies (VABBs) documented as DCIS were reviewed. Surgery was performed in all cases. We retrospectively collected the reports of post-VABB complete lesion removal and the histological results of the biopsy and surgery. We calculated the rate of upgrade of DCIS identified on VABB upon excision for patients with post-biopsy complete lesion removal and for those showing residual lesion. Results: We observed 2173 cases of DCIS: 408 classified as low-grade, 1262 as intermediate-grade, and 503 as high-grade. The overall upgrading rate to invasive carcinoma was 15.2% (330/2173). The upgrade rate was 8.2% in patients showing mammographically documented complete removal of the lesion and 19% in patients without complete removal. Conclusion: The absence of mammographically documented residual lesion following VABB was found to be associated with a lower upgrading rate of DCIS to invasive carcinoma on surgical excision and should be considered when deciding the proper management DCIS diagnosis.

Multi-modal imaging of high-risk ductal carcinoma in situ of the breast using C2Am: a targeted cell death imaging agent

BACKGROUND

Ductal carcinoma in situ (DCIS) is a non-invasive form of early breast cancer, with a poorly understood natural history of invasive transformation. Necrosis is a well-recognized adverse prognostic feature of DCIS, and non-invasive detection of its presence and spatial extent could provide information not obtainable by biopsy. We describe here imaging of the distribution and extent of comedo-type necrosis in a model of human DCIS using C2Am, an imaging agent that binds to the phosphatidylserine exposed by necrotic cells.

METHODS

We used an established xenograft model of human DCIS that mimics the histopathological features of the disease. Planar near-infrared and optoacoustic imaging, using fluorescently labeled C2Am, were used to image non-invasively the presence and extent of lesion necrosis.

RESULTS

C2Am showed specific and sensitive binding to necrotic areas in DCIS tissue, detectable both in vivo and ex vivo. The imaging signal generated in vivo using near-infrared (NIR) fluorescence imaging was up to 6-fold higher in DCIS lesions than in surrounding fat pad or skin tissue. There was a correlation between the C2Am NIR fluorescence (Pearson R = 0.783, P = 0.0125) and optoacoustic signals (R > 0.875, P < 0.022) in the DCIS lesions in vivo and the corresponding levels of cell death detected histologically.

CONCLUSIONS

C2Am is a targeted multi-modal imaging agent that could complement current anatomical imaging methods for detecting DCIS. Imaging the presence and spatial extent of necrosis may give better prognostic information than that obtained by biopsy alone.

Morphological intratumor heterogeneity in ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous disease in terms of morphological characteristics, protein expression profiles, genetic abnormalities, and potential for progression. Molecular heterogeneity has been extensively studied in DCIS. Yet morphological heterogeneity remains relatively undefined. This study investigated morphological intratumor heterogeneity in a series of 51 large DCIS. Nuclear atypia, DCIS architecture, necrosis, calcifications, stromal architecture, and stromal inflammation were assessed in one biopsy slide and three representative slides from each corresponding resection. For each histopathological feature, a histo-score was determined per slide and compared between the biopsy and the resection, as well as within a single resection. Statistical analysis comprised of Friedman tests, post hoc Wilcoxon tests with Bonferroni corrections, Mann-Whitney U tests, and chi-square tests. Despite substantial morphological heterogeneity in around 50% of DCIS, the histopathological assessment of the biopsy did not statistically significantly differ from the resection. Morphological heterogeneity was not significantly associated with patient age, DCIS size, or type of surgery, except for a weak association between heterogeneous stromal inflammation and smaller DCIS size. At the group level, the degree of heterogeneity did not significantly affect the representativity of a biopsy. At the individual patient level, however, the presence of necrosis, intraductal calcifications, myxoid stromal changes, and high-grade nuclear atypia was underestimated in a minority of DCIS patients. This study confirms the presence of morphological heterogeneity in DCIS for all six evaluated histopathological features. This should be kept in mind when taking biopsy-based treatment decisions for DCIS patients.

Diagnosis of ductal carcinoma in situ in an era of de-escalation of therapy

Concerns about overdiagnosis and overtreatment have led to interest in de-escalating treatment for ductal carcinoma in situ (DCIS). This article reviews the epidemiology, natural history, and current treatment options for DCIS and discusses ongoing efforts to further de-escalate treatment for these patients.

Association Between Time to Operation and Pathologic Stage in Ductal Carcinoma in Situ and Early-Stage Hormone Receptor-Positive Breast Cancer

Background

During the COVID-19 pandemic, surgical delays have been common for patients with ductal carcinoma in situ (DCIS) and early-stage estrogen receptor-positive (ER+) breast cancer, often in favor of neoadjuvant endocrine therapy (NET). To understand possible ramifications of these delays, we examined the association between time to operation and pathologic staging and overall survival (OS).

Study Design

Patients with DCIS or ER+ cT1-2N0 breast cancer treated from 2010 through 2016 were identified in the National Cancer Database. Time to operation was recorded. Factors associated with pathologic upstaging were examined using logistic regression analyses. Cox proportional hazard models were used to analyze OS. Analyses were stratified by disease stage and initial treatment strategy.

Results

There were 378,839 patients identified. Among those undergoing primary surgical procedure, time to operation was within 120 days in > 98% in all groups. Among cT1-2N0 patients selected for NET, operations were performed within 120 days in 59.6% of cT1N0 and 30.9% of cT2N0 patients. Increased time to operation was associated with increased odds of pathologic upstaging in DCIS patients (ER+: 60 to 120 days: odds ratio 1.15; 95% CI, 1.08 to 1.22; more than 120 days: odds ratio 1.44; 95% CI, 1.24 to 1.68; ER–: 60 to 120 days: NS; more than 120 days: odds ratio 1.36; 95% CI, 1.01 to 1.82; 60 days or less: reference), but not in patients with invasive cancer, irrespective of initial treatment strategy. No difference in OS was seen by time to operation in DCIS or NET patients.

Conclusions

Increased time to operation was associated with a small increase in pathologic upstaging in DCIS patients, but did not impact OS. In patients with cT1-2N0 disease, NET use did not impact stage or OS, supporting the safety of delay strategies in ER+ breast cancer patients during the pandemic.

CDH2/N-cadherin and early diagnosis of invasion in patients with ductal carcinoma in situ

PURPOSE

This proof-of-concept study investigates gene expression in core needle biopsies (CNB) to predict whether individuals diagnosed with ductal carcinoma in situ (DCIS) on CNB were affected by invasion at the time of diagnosis.

METHODS

Using a QuantiGene Plex 2.0 assay, 14 gene expression profiling was performed in 303 breast tissue samples. Preoperative diagnostic performance of a gene was measured by area under receiver-operating characteristic curve (AUC) with 95% confidence interval (CI). The gene mRNA positivity cutoff was computed using Gaussian mixture model (GMM); protein expression was measured by immunohistochemistry; DNA methylation was evaluated by targeted bisulfite sequencing.

RESULTS

mRNA from 69% (34/49) mammoplasties, 72% (75/104) CNB DCIS, and 89% (133/150) invasive breast cancers (IBC) were analyzed. Based on pre-and post-surgery DCIS chart reviews, 21 cases were categorized as DCIS synchronous with invasion and 54 DCIS were pure DCIS without pathologic evidence of invasive disease. The ectopic expression of neuronal cadherin CDH2 was probable in 0% mammoplasties, 6% pure DCIS, 29% synchronous DCIS, and 26% IBC. The CDH2 mRNA positivity in preoperative biopsies showing pure DCIS was predictive of a final diagnosis of invasion (AUC = 0.67; 95% CI 0.53-0.80; P = 0.029). Site-specific methylation of the CDH2 promoter (AUC = 0.76; 95% CI 0.54-0.97; P = 0.04) and measurements of N-cadherin, a pro-invasive cell-cell adhesion receptor encoded by CDH2 (AUC = 0.8; 95% CI 0.66-0.99; P < 0.005) had a discriminating power allowing for discernment of CDH2-positive biopsy.

CONCLUSIONS

Evidence of CDH2/N-cadherin expression, predictive of invasion synchronous with DCIS, may help to clarify a diagnosis and direct the course of therapy earlier in a patient's care.

Do Eligibility Criteria for Ductal Carcinoma In Situ (DCIS) Active Surveillance Trials Identify Patients at Low Risk for Upgrade to Invasive Carcinoma?

BACKGROUND

Clinical trials are currently ongoing to determine the safety and efficacy of active surveillance (AS) versus usual care (surgical and radiation treatment) for women with ductal carcinoma in situ (DCIS). This study aimed to determine upgrade rates of DCIS at needle biopsy to invasive carcinoma at surgery among women who meet the eligibility criteria for AS trials.

METHODS

A retrospective review was performed of consecutive women at an academic medical center with a diagnosis of DCIS at needle biopsy from 2007 to 2016. Medical records were reviewed for mode of presentation, imaging findings, biopsy pathology results, and surgical outcomes. Each patient with DCIS was evaluated for AS trial eligibility based on published criteria for the COMET, LORD, and LORIS trials.

RESULTS

During a 10-year period, DCIS was diagnosed in 858 women (mean age 58 years; range 28-89 years). Of the 858 women, 498 (58%) were eligible for the COMET trial, 101 (11.8%) for the LORD trial, and 343 (40%) for the LORIS trial. The rates of upgrade to invasive carcinoma were 12% (60/498) for the COMET trial, 5% (5/101) for the LORD trial, and 11.1% (38/343) for the LORIS trial. The invasive carcinomas ranged from 0.2 to 20 mm, and all were node-negative.

CONCLUSIONS

Women who meet the eligibility criteria for DCIS AS trials remain at risk for occult invasive carcinoma at presentation, with upgrade rates ranging from 5 to 12%. These findings suggest that more precise criteria are needed to ensure that women with invasive carcinoma are excluded from AS trials.

Treatment of Ductal Carcinoma in Situ: Considerations for Tailoring Therapy in the Contemporary Era

Purpose of Review

Standard options for the treatment of ductal carcinoma in situ (DCIS) include breast-conserving surgery (BCS) alone; BCS with radiotherapy or endocrine therapy, or both; and mastectomy. Survival is excellent with all options, but rates of local recurrence (LR) vary, as do quality-of-life measures. Here we discuss treatment outcomes, risk factors for LR, and tools for risk estimation.

Recent Findings

After BCS, radiotherapy reduces the risk of LR by half, and endocrine therapy reduces the risk by a third. Young age, inadequate margins, and greater volume of disease are associated with higher risk of LR after BCS, while young age, high grade, and microinvasion are associated with higher risk of locoregional recurrence after mastectomy. Clinical tools, including the Memorial Sloan Kettering Cancer Center (MSKCC) DCIS nomogram, provide LR risk estimates after BCS that appear more accurate than current genomic assays. The safety of active surveillance for seemingly low-risk patients remains uncertain.

Summary

Estimation of LR risk, utilizing a multitude of clinicopathologic and treatment factors, can help a woman balance that risk with her values and priorities, and allow her to choose the optimal treatment option for her.

Low-Grade Ductal Carcinoma In Situ

OBJECTIVES

We aimed to determine the interobserver reproducibility in diagnosing low-grade ductal carcinoma in situ (DCIS). We also aimed to compare the interobserver variability using a proposed two-tiered grading system as opposed to the current three-tiered system.

METHODS

Three expert breast pathologists and one junior pathologist identified low-grade DCIS from a set of 300 DCIS slides. Months later, participants were asked to grade the 300 cases using the standard three-tiered system.

RESULTS

Using the two-tiered system, interobserver agreement among breast pathologists was considered moderate (κ = 0.575). The agreement was similar (κ = 0.532) with the junior pathologist included. Using the three-tiered system, pathologists' agreement was poor (κ = 0.235).

CONCLUSIONS

Pathologists' reproducibility on diagnosing low-grade DCIS showed moderate agreement. Experience does not seem to influence reproducibility. Our proposed two-tiered system of low vs nonlow grade, where the intermediate grade is grouped in the nonlow category has shown improved concordance.

Reliability of preoperative breast biopsies showing ductal carcinoma in situ and implications for non-operative treatment: a cohort study

PURPOSE

The future of non-operative management of DCIS relies on distinguishing lesions requiring treatment from those needing only active surveillance. More accurate preoperative staging and grading of DCIS would be helpful. We identified determinants of upstaging preoperative breast biopsies showing ductal carcinoma in situ (DCIS) to invasive breast cancer (IBC), or of upgrading them to higher-grade DCIS, following examination of the surgically excised specimen.

METHODS

We studied all women with DCIS at preoperative biopsy in a large specialist cancer centre during 2000-2014. Information from clinical records, mammography, and pathology specimens from both preoperative biopsy and excised specimen were abstracted. Women suspected of having IBC during biopsy were excluded.

RESULTS

Among 606 preoperative biopsies showing DCIS, 15.0% (95% confidence interval 12.3-18.1) were upstaged to IBC and a further 14.6% (11.3-18.4) upgraded to higher-grade DCIS. The risk of upstaging increased with presence of a palpable lump (21.1% vs 13.0%, pdifference = 0.04), while the risk of upgrading increased with presence of necrosis on biopsy (33.0% vs 9.5%, pdifference < 0.001) and with use of 14G core-needle rather than 9G vacuum-assisted biopsy (22.8% vs 7.0%, pdifference < 0.001). Larger mammographic size increased the risk of both upgrading (pheterogeneity = 0.01) and upstaging (pheterogeneity = 0.004).

CONCLUSIONS

The risk of upstaging of DCIS in preoperative biopsies is lower than previously estimated and justifies conducting randomized clinical trials testing the safety of active surveillance for lower grade DCIS. Selection of women with low grade DCIS for such trials, or for active surveillance, may be improved by consideration of the additional factors identified in this study.

Estimating the benefits of therapy for early-stage breast cancer: the St. Gallen International Consensus Guidelines for the primary therapy of early breast cancer 2019

BACKGROUND

The 16th St. Gallen International Breast Cancer Conference 2019 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer.

DESIGN

Treatments were assessed in light of their intensity, duration and side-effects, estimating the magnitude of clinical benefit according to stage and biology of the disease. The Panel acknowledged that for many patients, the impact of adjuvant therapy or the adherence to specific guidelines may have modest impact on the risk of breast cancer recurrence or overall survival. For that reason, the Panel explicitly encouraged clinicians and patients to routinely discuss the magnitude of benefit for interventions as part of the development of the treatment plan.

RESULTS

The guidelines focus on common ductal and lobular breast cancer histologies arising in generally healthy women. Special breast cancer histologies may need different considerations, as do individual patients with other substantial health considerations. The panelists' opinions reflect different interpretation of available data and expert opinion where is lack of evidence and sociocultural factors in their environment such as availability of and access to medical service, economic resources and reimbursement issues. Panelists encourage patient participation in well-designed clinical studies whenever available.

CONCLUSIONS

With these caveats in mind, the St. Gallen Consensus Conference seeks to provide guidance to clinicians on appropriate treatments for early-stage breast cancer and guidance for weighing the realistic tradeoffs between treatment and toxicity so that patients and clinical teams can make well-informed decisions on the basis of an honest reckoning of the magnitude of clinical benefit.

Risk of Contralateral Breast Cancer in Women with Ductal Carcinoma In Situ Associated with Synchronous Ipsilateral Lobular Carcinoma In Situ

BACKGROUND

Lobular carcinoma in situ (LCIS) is a risk factor for breast cancer, but the effect of LCIS found in association with ductal carcinoma in situ (DCIS) is unknown. In this study, we compared contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) rates among women with DCIS with or without synchronous ipsilateral LCIS treated with breast-conserving surgery (BCS).

METHODS

DCIS patients undergoing BCS from 2000 to 2011 with a contralateral breast at risk were stratified by the presence or absence of synchronous ipsilateral LCIS with the index DCIS (DCIS + LCIS vs. DCIS). Those with contralateral, bilateral, or prior ipsilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated.

RESULTS

Of 1888 patients identified, 1475 (78%) had DCIS and 413 (22%) had DCIS + LCIS. At median follow-up of 7.2 (range 0-17) years, 307 patients had a subsequent first breast event; 207 IBTR and 100 CBC. The 10-year cumulative incidence of IBTR was similar in both groups: 15.0% vs. 14.2% (log-rank, p = 0.8) for DCIS + LCIS vs. DCIS, respectively. The 10-year cumulative incidence of CBC was greater in the DCIS + LCIS group: 10.9% vs. 6.1% for DCIS (log-rank, p < 0.001). After adjustment for other factors, CBC risk remained higher in DCIS + LCIS compared with DCIS (hazard ratio 2.06, 95% confidence interval 1.36-3.11, p = 0.001); there was no significant difference in IBTR risk.

CONCLUSIONS

Compared with DCIS alone, DCIS + LCIS is associated with similar IBTR risk but double the risk of CBC. This finding should inform treatment decisions, in particular regarding endocrine therapy for risk reduction.

Ductal carcinoma in situ of breast: update 2019

Ductal carcinoma in situ is a non-invasive form of breast cancer. Its incidence is increasing due to widespread use of mammographic screening. It presents several diagnostic and management challenges in part due to its relatively indolent behaviour. Most series analysing biomarkers in these lesions are small (<100 patients) and large clinical trials have not been frequent. Herein, we review the recent progress made in understanding the biology of this entity and the tools available for prognostication.

Surgical management of ductal carcinoma in situ of the breast: A large retrospective study from a single institution

BACKGROUND

Management of breast ductal carcinoma in situ (DCIS) has various approaches with distinct institutional specific practice. Here, we review DCIS management in a single institution with emphasize on re-operation rates and outcome.

METHODS

Breast ductal carcinoma in situ cases diagnosed at the Nottingham Breast Institute between 1987 and 2017 were identified (n = 1249). Clinicopathological data were collected. Cases were histologically reviewed, and different factors associated with primary operation selection, re-excision, presence of residual tumor in the re-excision specimens, use of radiotherapy and ipsilateral recurrences were analyzed.

RESULTS

34% of DCIS patients were initially treated by mastectomy and were more frequently symptomatic, of high nuclear tumor grade, size >40 mm, and associated with comedo necrosis and Paget's disease of the nipple. Further surgery was due to involved or narrow surgical margins. Residual tumor tissue was detected in 53% of the re-excision specimens. Re-excision rates of patients treated with breast-conserving surgery (BCS) were reduced from approximately 70% to 23%, and the final mastectomy rates decreased from 60% to 20%. Changes in surgical practice with acceptance of smaller excision margins and more frequent use of local radiotherapy have led to a significant decrease not only in the re-excision rate but also in the final mastectomy rate together with non-significant reduction in 5- and 10-year local recurrence rates.

CONCLUSION

Although BCS is increasingly the preferred primary surgical option for DCIS management, a proportion of low-risk DCIS patients continue to undergo re-excision surgery or completion mastectomy. Despite acceptance of smaller margins, recurrence rate is decreasing.

Ductal carcinoma in situ of the breast: an update for the pathologist in the era of individualized risk assessment and tailored therapies

Ductal carcinoma in situ (DCIS) is a neoplastic proliferation of mammary ductal epithelial cells confined to the ductal-lobular system, and a non-obligate precursor of invasive disease. While there has been a significant increase in the diagnosis of DCIS in recent years due to uptake of mammography screening, there has been little change in the rate of invasive recurrence, indicating that a large proportion of patients diagnosed with DCIS will never develop invasive disease. The main issue for clinicians is how to reliably predict the prognosis of DCIS in order to individualize patient treatment, especially as treatment ranges from surveillance only, breast-conserving surgery only, to breast-conserving surgery plus radiotherapy and/or hormonal therapy, and mastectomy with or without radiotherapy. We conducted a semi-structured literature review to address the above issues relating to "pure" DCIS. Here we discuss the pathology of DCIS, risk factors for recurrence, biomarkers and molecular signatures, and disease management. Potential mechanisms of progression from DCIS to invasive cancer and problems faced by clinicians and pathologists in diagnosing and treating this disease are also discussed. Despite the tremendous research efforts to identify accurate risk stratification predictors of invasive recurrence and response to radiotherapy and endocrine therapy, to date there is no simple, well-validated marker or group of variables for risk estimation, particularly in the setting of adjuvant treatment after breast-conserving surgery. Thus, the standard of care to date remains breast-conserving surgery plus radiotherapy, with or without hormonal therapy. Emerging tools, such as pathologic or biologic markers, may soon change such practice. Our review also includes recent advances towards innovative treatment strategies, including targeted therapies, immune modulators, and vaccines.

A retrospective alternative for active surveillance trials for ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) of the breast is a nonobligate precursor of invasive breast cancer, accounting for 20 % of screen-detected breast cancers. Little is known about the natural progression of DCIS because most patients undergo surgery upon diagnosis. Many DCIS patients are likely being overtreated, as it is believed that only around 50 % of DCIS will progress to invasive carcinoma. Robust prognostic markers for progression to invasive carcinoma are lacking. In the past, studies have investigated women who developed a recurrence after breast-conserving surgery (BCS) and compared them with those who did not. However, where there is no recurrence, the patient has probably been adequately treated. The present narrative review advocates a new research strategy, wherein only those patients with a recurrence are studied. Approximately half of the recurrences are invasive cancers, and half are DCIS. So-called "recurrences" are probably most often the result of residual disease. The new approach allows us to ask: why did some residual DCIS evolve to invasive cancers and others not? This novel strategy compares the group of patients that developed in situ recurrence with the group of patients that developed invasive recurrence after BCS. The differences between these groups could then be used to develop a robust risk stratification tool. This tool should estimate the risk of synchronous and metachronous invasive carcinoma when DCIS is diagnosed in a biopsy. Identification of DCIS patients at low risk for developing invasive carcinoma will individualize future therapy and prevent overtreatment.

Can tumor-associated macrophages in ductal carcinoma in situ on biopsy predict invasive carcinoma on excision?

Recent trials have explored surveillance of ductal carcinoma in situ (DCIS) without complete excision, but it is difficult to fully exclude an associated, unsampled invasive focus. Tumor microenvironment, including tumor-associated macrophages, may play a role in the transition from in situ to invasive carcinoma, and the presence of CD163-positive cells with DCIS has been associated with increased risk of progression to invasive carcinoma. We aimed to evaluate the role of DCIS-associated CD163-positive cells on biopsy in predicting associated invasion on excision. Immunohistochemistry for CD163 was performed on 57 total biopsy cases of DCIS of low (n = 13), intermediate (n = 21), and high (n = 23) nuclear grade, 27 (47%) of which showed invasion on the subsequent excision specimen. Positive intratumoral and stromal cells were quantified independently by 2 observers based on the percentage of cells staining. Intratumoral CD163 scores ranged from 0 to 2 (mean, 0.7). Stromal CD163 scores ranged from 0 to 3 (mean, 1.3). Intratumoral and stromal CD163 levels were not significantly associated with the presence of subsequent invasion when evaluated as a whole group (P = .36 and P = .47) or when subdivided into low (P = .36 and P = .17), intermediate (P = .82 and P = .82), or high (P = .09 and P = .68) nuclear grades. There was no correlation between intratumoral CD163 content and DCIS grade (P = .257). A trend for higher stromal CD163 expression was seen with higher-grade DCIS, although not statistically significant (P = .178). In conclusion, CD163 on breast core biopsy does not help select patients who may safely forgo excision of DCIS.

Not All Ductal Carcinomas In Situ Are Created IDLE (Indolent Lesions of Epithelial Origin)

CONTEXT.—

Mammographic screening has increased the incidence of ductal carcinoma in situ (DCIS), but this has not been accompanied by a decline in the incidence of invasive carcinoma (IC). Consequently, the surgical treatment of DCIS has recently been questioned, with some advocating only surveillance (with or without neoadjuvant endocrine therapy) after a core biopsy diagnosis of DCIS.

OBJECTIVES.—

To examine the predictive value of a core biopsy diagnosis of DCIS, particularly the upgrade rate to IC, and to identify associated factors.

DESIGN.—

Using the pathology database, we identified 2943 cases of DCIS diagnosed on core biopsy from 2000 to 2015, of which 229 cases (8%) later had the stage upgraded to IC.

RESULTS.—

Ages ranged from 25 to 90 years (mean, 59 years). The DCIS presented with calcifications in 151 of 229 cases (65.9%), was widespread in 26 of 151 cases (17%), had a mass or density present in 70 of 229 cases (31%), with heterogeneous echogenic features in 44 of those 70 cases (63%), and an enhancement upon magnetic resonance imaging in 8 of 229 cases (3.5%). Of the 229 cases, the DCIS grades were as follows: low in 29 cases (13%), intermediate in 79 cases (36%), and high in 121 cases (53%). Of the 229 cases, necrosis was present in 152 (66.4%) and was comedo necrosis in 99 cases (43%). Of the 229 cases of IC, the tumor stage was as follows: microIC in 36 (16%), T1a in 119 (52%), T1b in 35 (15%), T1c in 28 (12%), T2 in 8 (3%), and T3 in 3 cases (1%). Axillary lymph nodes were staged in 167 patients as follows: N0, 141 cases (84%); N0(i+), 14 cases (8%); and N1, 12 cases (7%). The 12 N1 cases were subclassified by T stage as follows: T1a, 1 case (8%); T1b, 4 cases (33%); T1c, 2 cases (17%); T2, 4 cases (33%); and T3, 1 case (8%). The IC cases of stage upgrading were predominantly smaller than 2 cm (218 of 229; 95%), and more than two-thirds were smaller than 0.5 cm (155 of 229; 95%), most of which were accompanied by extensive DCIS.

CONCLUSIONS.—

Approximately one-half of the upgrades were associated with high-grade DCIS, especially with comedo necrosis; nevertheless, the other one-half of the upgrades were due to low- and intermediate-grade DCIS and should not be underestimated. There were few positive results from axillary lymph node biopsies, but they occurred in 3% (7 of 218) of the carcinomas smaller than 2 cm. Our findings indicate that caution is needed when DCIS cases diagnosed by core biopsy are treated nonsurgically with surveillance (with or without neoadjuvant endocrine therapy), given the number of cases (229 of 2943; 8%) that are upgraded to IC and those with axillary lymph node metastases (12 of 167; 7%).

Ductal carcinoma in situ current trends, controversies, and review of literature

Ductal carcinoma in situ (DCIS) is a non-obligate precursor, non-invasive malignancy confined within the basement membrane of the breast ductal system. There is a wide variation in the natural history of DCIS with an estimated incidence of progression to invasive ductal carcinoma being at least 13%-50% over a range of 10 or more years after initial diagnosis. Regardless of the treatment strategy, long-term survival is excellent. The controversy surrounding DCIS relates to preventing under-treatment, while also avoiding unnecessary treatments. In this article, we review the incidence, presentation, management options and surveillance of DCIS. Furthermore, we address several current controversies related to the management of DCIS, including margin status, sentinel node biopsy, hormonal therapy, the role of radiation in breast conservation surgery, and various risk stratification schemes.

Feasibility of the Less Is More Approach in Treating Low-Risk Ductal Carcinoma In Situ Diagnosed on Core Needle Biopsy: Ten-Year Review of Ductal Carcinoma In Situ Upgraded to Invasion at Surgery

CONTEXT

- Ductal carcinoma in situ (DCIS) represents 20% of screen-detected breast cancers. The likelihood that certain types of DCIS are slow growing and may never progress to invasion suggests that our current standards of treating DCIS could result in overtreatment. The LORIS (LOw RISk DCIS) and LORD (LOw Risk DCIS) trials address these concerns by randomizing patients with low-risk DCIS to either active surveillance or conventional treatment.

OBJECTIVE

- To determine the upgrade rate of DCIS diagnosed on core needle biopsy to invasive carcinoma at surgery and to evaluate the safety of managing low-risk DCIS with surveillance alone, by characterizing the pathologic and clinical features of upgraded cases and applying criteria of the LORD and LORIS trials to these cases.

DESIGN

- A 10-year retrospective analysis of DCIS on core needle biopsy with subsequent surgery.

RESULTS

- We identified 1271 cases of DCIS on core needle biopsy: 200 (16%) low grade, 649 (51%) intermediate grade, and 422 (33%) high grade. Of the 1271 cases, we found an 8% upgrade rate to invasive carcinoma (n = 105). Nineteen of the 105 upgraded cases (18%) had positive lymph nodes. Low-grade DCIS was least likely to upgrade to invasion, comprising 10% (10 of 105) of upgraded cases. Three of the 105 upgraded cases (3%) met criteria for the LORD trial, and all were low-grade DCIS on core needle biopsy with favorable biology on follow-up.

CONCLUSIONS

- There is a clear risk of upgrade to invasion on follow-up excision; however, applying strict criteria of the LORD trial effectively decreases the likelihood of a missed invasive component or missed aggressive pathologic features.

Active surveillance of women diagnosed with atypical ductal hyperplasia on core needle biopsy may spare many women potentially unnecessary surgery, but at the risk of undertreatment for a minority: 10-year surgical outcomes of 114 consecutive cases from a single center

A needle core biopsy diagnosis of atypical ductal hyperplasia is an indication for open biopsy. The launch of randomized clinical trials of active surveillance for low-risk ductal carcinoma in situ leads to the paradoxical situation of women with low-grade ductal carcinoma in situ being observed, whereas those with atypical ductal hyperplasia have surgery. If the malignancies diagnosed after surgery for atypical ductal hyperplasia are dominated by low-risk ductal carcinoma in situ, women with atypical ductal hyperplasia may also be considered for surveillance. This 10-year prospective observational study includes women diagnosed with atypical ductal hyperplasia on core biopsy after screening mammography. We retrieved their clinical, imaging and histologic data and carried out a blind review of core biopsy histology, sub-classifying the atypical ductal hyperplasia along a spectrum from hyperplasia to ductal carcinoma in situ. Using the final surgical pathology data, we calculated: (1) The proportion and grades of ductal carcinoma in situ and invasive cancers diagnosed at open biopsy. (2) The histologic extent of the malignancy at surgery. (3) The biomarker profile and nodal status of any invasive cancers. (4) Ascertained any independent predictors of (i) any malignancy, (ii) high-risk malignancy, defined in this study as invasive cancer, or high-grade ductal carcinoma in situ, or intermediate grade ductal carcinoma in situ with any necrosis. (5) Extrapolated the above to simulate active surveillance for women with screen-detected atypical ductal hyperplasia. Between January 2005 and December 2014, 114 women, mean age 59 years (range 40-79 years) were included. Surgical pathology, available in 110 (97%), confirmed malignancy in 46 (40%). All 46 malignant cases had ductal carcinoma in situ, accompanied by invasive carcinoma in 9 (8%) women. Together, 21 (19%) women had either invasive cancer (9%), high-grade ductal carcinoma in situ (6%), or necrotizing, intermediate grade ductal carcinoma in situ (6%). Only one of nine invasive breast cancers was grade 1, 3 were multifocal, all were ≤8 mm, node negative, and ER positive but two were HER2 amplified. The mean extent of the ductal carcinoma in situ in any one specimen was 19.8 mm, median 13 mm, range 2-110 mm. Overall 32 women, 29% of the whole cohort and 70% of those 46 with malignancy, required further surgery, including mastectomy in 12 (11%). A multivariable model for predicting the likelihood of any malignancy showed a statistically significant association only with the post review subtype of atypical ductal hyperplasia, adjusting for lesion size. Independent predictors of high-risk malignancy (invasive cancer or non-low-grade ductal carcinoma in situ) were not identified. If active surveillance is adopted for screen-detected atypical ductal hyperplasia diagnosed on core biopsy, 60% of women will avoid unnecessary surgery and a further 24% would meet eligibility criteria for ductal carcinoma in situ surveillance trials. However, 18% of women will have undiagnosed invasive breast cancer or non-low-risk ductal carcinoma in situ. These women with high-risk lesions are not reliably identified pre-operatively.

Controversies in the Treatment of Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) accounts for 20% of all newly diagnosed breast cancers. Mastectomy was once the gold standard for the treatment of DCIS; however, breast-conserving surgery (BCS) has been adopted as the treatment of choice for patients with small, screen-detected lesions. Both adjuvant radiation and hormonal therapy following BCS have been demonstrated in randomized trials to reduce the risk of both invasive and DCIS recurrence, but neither affects survival. With the variety of surgical and adjuvant treatment options available, there has been great interest in tailoring the treatment to the individual, with the goal of optimizing the balance of risks and benefits according to the values and priorities of the woman herself. Prospective studies of women with "low-risk" DCIS treated with BCS alone have successfully identified women at lower than average risk but have not achieved the goal of identifying a subset of women with DCIS at minimal risk of recurrence after surgical excision alone. No studies have evaluated the safety of medical management alone.