A multigene expression assay to predict local recurrence risk for ductal carcinoma in situ of the breast

Article Commentary: Controversies Regarding the Diagnosis and Management of Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) is a premalignant condition, whose incidence is increasing in the current era of widespread screening mammography. While eminently treatable, there are innumerable controversies that surround this disease in terms of its diagnosis and treatment. We discuss these issues and review the data to date regarding this condition which affects roughly 20 per cent of all patients presenting with breast cancer.

Studies on DNA Damage Repair and Precision Radiotherapy for Breast Cancer

Radiotherapy acts as an important component of breast cancer management, which significantly decreases local recurrence in patients treated with conservative surgery or with radical mastectomy. On the foundation of technological innovation of radiotherapy setting, precision radiotherapy of cancer has been widely applied in recent years. DNA damage and its repair mechanism are the vital factors which lead to the formation of tumor. Moreover, the status of DNA damage repair in cancer cells has been shown to influence patient response to the therapy, including radiotherapy. Some genes can affect the radiosensitivity of tumor cell by regulating the DNA damage repair pathway. This chapter will describe the potential application of DNA damage repair in precision radiotherapy of breast cancer.

The prevalence and clinical relevance of tumor-infiltrating lymphocytes (TILs) in ductal carcinoma in situ of the breast

Background

Tumor-infiltrating lymphocytes (TILs) are a robust prognostic adjunct in invasive breast cancer, but their clinical role in ductal carcinoma in situ (DCIS) has not been ascertained.

Patients and methods

We evaluated the prevalence and clinical relevance of TILs in a well annotated series of 1488 consecutive DCIS women with a median follow-up of 8.2 years. Detailed criteria for TILs evaluation were pre-defined involving the International Immuno-Oncology Biomarker Working Group. TILs percentage was considered both as a continuous and categorical variable. Levels of TILs were examined for their associations with ipsilateral breast event (IBE), whether in situ or invasive.

Results

Of the 1488 patients with DCIS under study, 35.1% had <1%, 58.3% 1-49% and 6.5% ≥50% peri-ductal stromal lymphocytes. The interobserver agreement in TILs evaluation, measured by the intraclass correlation coefficient (ICC) was 0.96 (95% CI 0.95-0.97). At univariable analysis, clinical factors significantly associated with TILs (P ≤0.001) were intrinsic subtype, grade, necrosis, type of surgery. Her-2 positive DCIS were more frequently associated with TILs (24% of patients with TILs ≥50%), followed by the triple negative (11%), Luminal B/Her-2 positive (9%) and Luminal A/B subtypes (1%) (P < 0.0001). We did not find any association between TILs as a continuous variable and the risk of IBEs. Likewise, when patients were stratified by TILs percentage (<1%, between 1% and 49.9%, and ≥50%), no statistically significant association was observed (10-year cumulative incidence of IBEs: 19%, 17.3%, and 18.7% respectively, P = 0.767).

Conclusion

TILs occur more frequently in the Her-2 positive DCIS. Although we did not find a significant association between TILs and the 10-year risk of IBE, our data suggest that immunotherapies might be considered in subsets of DCIS patients.

Androgen and oestrogen receptors as potential prognostic markers for patients with ductal carcinoma in situ treated with surgery and radiotherapy

Ductal carcinoma in situ (DCIS) is a heterogeneous disease that has been investigated less extensively than invasive breast cancer. Women with DCIS are mainly treated with conservative surgery almost exclusively followed by radiotherapy. However, as radiation treatment is not always effective, the search for biomarkers capable of identifying DCIS lesions that could progress to invasive cancer is ongoing. Although conventional biomarkers have been thoroughly studied in invasive tumours, little is known about the role played by androgen receptor (AR), widely expressed in DCIS. A series of 42 DCIS patients treated with quadrantectomy and radiotherapy were followed for a period of up to 95 months. Of these, 11 had recurrent DCIS or progressed to invasive cancer. All tumours were analysed for clinical pathological features. Conventional biomarkers and androgen receptor expression were determined by immunohistochemistry. Our results showed that AR was higher in tumours of relapsed patients than non-relapsed patients (P value: 0.0005). Conversely, oestrogen receptor (ER) was higher, albeit not significantly, in non-relapsed patients than in relapsed patients. AR/ER ratio was considerably different in the two subgroups (P value: 0.0033). Area under the curve (AUC) values were 0.85 for AR and 0.80 for the AR/ER ratio. These preliminary results highlight the potentially important role of both AR and the AR/ER ratio as prognostic markers in DCIS.

Comparative effectiveness of incorporating a hypothetical DCIS prognostic marker into breast cancer screening

PURPOSE

Due to limitations in the ability to identify non-progressive disease, ductal carcinoma in situ (DCIS) is usually managed similarly to localized invasive breast cancer. We used simulation modeling to evaluate the potential impact of a hypothetical test that identifies non-progressive DCIS.

METHODS

A discrete-event model simulated a cohort of U.S. women undergoing digital screening mammography. All women diagnosed with DCIS underwent the hypothetical DCIS prognostic test. Women with test results indicating progressive DCIS received standard breast cancer treatment and a decrement to quality of life corresponding to the treatment. If the DCIS test indicated non-progressive DCIS, no treatment was received and women continued routine annual surveillance mammography. A range of test performance characteristics and prevalence of non-progressive disease were simulated. Analysis compared discounted quality-adjusted life years (QALYs) and costs for test scenarios to base-case scenarios without the test.

RESULTS

Compared to the base case, a perfect prognostic test resulted in a 40% decrease in treatment costs, from $13,321 to $8005 USD per DCIS case. A perfect test produced 0.04 additional QALYs (16 days) for women diagnosed with DCIS, added to the base case of 5.88 QALYs per DCIS case. The results were sensitive to the performance characteristics of the prognostic test, the proportion of DCIS cases that were non-progressive in the model, and the frequency of mammography screening in the population.

CONCLUSION

A prognostic test that identifies non-progressive DCIS would substantially reduce treatment costs but result in only modest improvements in quality of life when averaged over all DCIS cases.

Factors Associated With Underestimation of Invasive Cancer in Patients With Ductal Carcinoma In Situ: Precautions for Active Surveillance

Importance

Recent recognition of the overdiagnosis and overtreatment of ductal carcinoma in situ (DCIS) detected by mammography has led to the development of clinical trials randomizing women with non-high-grade DCIS to active surveillance, defined as imaging surveillance with or without endocrine therapy, vs standard surgical care.

Objective

To determine the factors associated with underestimation of invasive cancer in patients with a clinical diagnosis of non-high-grade DCIS that would preclude active surveillance.

Design, Setting, and Participants

A retrospective cohort study was conducted using records from the National Cancer Database from January 1, 1998, to December 31, 2012, of female patients 40 to 99 years of age with a clinical diagnosis of non-high-grade DCIS who underwent definitive surgical treatment. Data analysis was conducted from November 1, 2015, to February 4, 2017.

Exposures

Patients with an upgraded diagnosis of invasive carcinoma vs those with a diagnosis of DCIS based on final surgical pathologic findings.

Main Outcomes and Measures

The proportions of cases with an upgraded diagnosis of invasive carcinoma from final surgical pathologic findings were compared by tumor, host, and system characteristics.

Results

Of 37 544 women (mean [SD] age, 59.3 [12.4] years) presenting with a clinical diagnosis of non-high-grade DCIS, 8320 (22.2%) had invasive carcinoma based on final pathologic findings. Invasive carcinomas were more likely to be smaller (>0.5 to ≤1.0 cm vs ≤0.5 cm: odds ratio [OR], 0.73; 95% CI, 0.67-0.79; >1.0 to ≤2.0 cm vs ≤0.5 cm: OR, 0.42; 95% CI, 0.39-0.46; >2.0 to ≤5.0 cm vs ≤0.5 cm: OR, 0.19; 95% CI, 0.17-0.22; and >5.0 cm vs ≤0.5 cm: OR, 0.11; 95% CI, 0.08-0.15) and lower grade (intermediate vs low: OR, 0.75; 95% CI, 0.69-0.80). Multivariate logistic regression analysis demonstrated that younger age (60-79 vs 40-49 years: OR, 0.84; 95% CI, 0.77-0.92; and ≥80 vs 40 to 49 years: OR, 0.76; 95% CI, 0.64-0.91), negative estrogen receptor status (positive vs negative: OR, 0.39; 95% CI, 0.34-0.43), treatment at an academic facility (academic vs community: OR, 2.08; 95% CI, 1.82-2.38), and higher annual income (>$63 000 vs <$38 000: OR, 1.14; 95% CI, 1.02-1.28) were significantly associated with an upgraded diagnosis of invasive carcinoma based on final pathologic findings.

Conclusions and Relevance

When selecting patients for active surveillance of DCIS, factors other than tumor biology associated with invasive carcinoma based on final pathologic findings may need to be considered. At the time of randomization to active surveillance, a significant proportion of patients with non-high-grade DCIS will harbor invasive carcinoma.

Seven-Year Outcomes Following Accelerated Partial Breast Irradiation Stratified by ASTRO Consensus Groupings

OBJECTIVES

Limited long-term data exist regarding outcomes for patients treated with accelerated partial breast irradiation (APBI), particularly, when stratified by American Society for Radiation Oncology (ASTRO) Consensus Statement (CS) risk groups. The purpose of this analysis is to present 5- and 7-year outcomes following APBI based on CS groupings.

MATERIALS AND METHODS

A total of 690 patients with early-stage breast cancer underwent APBI from 1993 to 2012, receiving interstitial brachytherapy (n=195), balloon-based brachytherapy (n=290), or 3-dimensional conformal radiotherapy (n=205) at a single institution. Patients were stratified into suitable, cautionary, and unsuitable groups with 5-year outcomes analyzed. Seven-year outcomes were analyzed for a subset with follow-up of ≥2 years (n=625).

RESULTS

Median follow-up was 6.7 years (range, 0.1 to 20.1 y). Patients assigned to cautionary and unsuitable categories were more likely to have high-grade tumors (21% to 25% vs. 9%, P=0.001), receive chemotherapy (15% to 38% vs. 6%, P<0.001), and have close/positive margins (9% to 11% vs. 0%, P<0.001). There was no difference in ipsilateral breast tumor recurrence at 5 or 7 years: 2.2%, 1.2%, 2.8% at 5 years (P=0.57), and 2.2%, 1.9%, 4.6% at 7 years (P=0.58) in the suitable, cautionary, and unsuitable groups, respectively. As compared with the suitable group, increased rates of distant metastases were noted for the unsuitable and cautionary groups at 5 years (P=0.04).

CONCLUSIONS

No differences in rates of ipsilateral breast tumor recurrence were seen at 5 or 7 years when stratified by ASTRO CS groupings. Modest increases in distant recurrence were noted in the cautionary and unsuitable groups. These findings suggest that the ASTRO CS groupings stratify more for systemic recurrence and may not appropriately select patients for whole versus partial breast irradiation.

Clinical risk score to predict likelihood of recurrence after ductal carcinoma in situ treated with breast-conserving surgery

PURPOSE

A majority of women with ductal carcinoma in situ (DCIS) receive breast-conserving surgery (BCS) but then face a risk of ipsilateral breast tumor recurrence (IBTR) which can be either recurrence of DCIS or invasive breast cancer. We developed a score to provide individualized information about IBTR risk to guide treatment decisions.

METHODS

Data from 2762 patients treated with BCS for DCIS at centers within the National Comprehensive Cancer Network (NCCN) were used to identify statistically significant non-treatment-related predictors for 5-year IBTR. Factors most associated with IBTR were estrogen-receptor status of the DCIS, presence of comedo necrosis, and patient age at diagnosis. These three parameters were used to create a point-based risk score. Discrimination of this score was assessed in a separate DCIS population of 301 women (100 with IBTR and 200 without) from Kaiser Permanente Northern California (KPNC).

RESULTS

Using NCCN data, the 5-year likelihood of IBTR without adjuvant therapy was 9% (95% CI 5-12%), 23% (95% CI 13-32%), and 51% (95% CI 26-75%) in the low, intermediate, and high-risk groups, respectively. Addition of the risk score to a model including only treatment improved the C-statistic from 0.69 to 0.74 (improvement of 0.05). Cross-validation of the score resulted in a C-statistic of 0.76. The score had a c-statistic of 0.67 using the KPNC data, revealing that it discriminated well.

CONCLUSIONS

This simple, no-cost risk score may be used by patients and physicians to facilitate preference-based decision-making about DCIS management informed by a more accurate understanding of risks.

Ductal Carcinoma In Situ Biology, Biomarkers, and Diagnosis

Ductal carcinoma in situ (DCIS) is an often-diagnosed breast disease and a known, non-obligate, precursor to invasive breast carcinoma. In this review, we explore the clinical and pathological features of DCIS, fundamental elements of DCIS biology including gene expression and genetic events, the relationship of DCIS with recurrence and invasive breast cancer, and the interaction of DCIS with the microenvironment. We also survey how these various elements are being used to solve the clinical conundrum of how to optimally treat a disease that has potential to progress, and yet is also likely over-treated in a significant proportion of cases.

Genomic Assays in Ductal Carcinoma In Situ: Implications for Management Decisions

OBJECTIVES

Breast cancer is the most common cancer in women and a leading cause of cancer death worldwide. The management of breast cancer depends on clinical and pathologic prognostic factors that help guide patient treatment. Ductal carcinoma in situ (DCIS) is a noninvasive form of breast cancer with an unpredictable risk of either progression to invasive disease or recurrence. To evaluate the utilization of the DCIS score in a large single-institution population and understand reasons for avoidance in eligible patients.

METHODS

A retrospective chart review of eligible patients with pure DCIS treated by lumpectomy (January 2011-May 2015) was performed. Patients were considered eligible for the assay if they met the Eastern Cooperative Oncology Group E5194 pathology criteria. All of the patients underwent breast-conserving surgery and were estrogen receptor positive.

RESULTS

Of 182 estrogen receptor-positive patients with DCIS who underwent breast-conserving surgery, 31 (17%) had a DCIS assay performed; however, most of the patients did not have a DCIS score assay performed, yet 47.9% of this cohort would have met the pathologic eligibility criteria. Conversely, 82.5% of the patients having the DCIS score evaluated actually met these criteria.

CONCLUSIONS

Tumor size, grade, ER status, and calcifications were drivers of patient selection for 12-gene assay use. E5194 eligibility criteria selected for low risk population. Although a large proportion of patients met eligibility criteria, DCIS Score was infrequently considered for recurrence risk estimation. When performed, assay scores supported omission of radiation for over 75% of cases.

Predicting clinical outcomes from large scale cancer genomic profiles with deep survival models

Translating the vast data generated by genomic platforms into accurate predictions of clinical outcomes is a fundamental challenge in genomic medicine. Many prediction methods face limitations in learning from the high-dimensional profiles generated by these platforms, and rely on experts to hand-select a small number of features for training prediction models. In this paper, we demonstrate how deep learning and Bayesian optimization methods that have been remarkably successful in general high-dimensional prediction tasks can be adapted to the problem of predicting cancer outcomes. We perform an extensive comparison of Bayesian optimized deep survival models and other state of the art machine learning methods for survival analysis, and describe a framework for interpreting deep survival models using a risk backpropagation technique. Finally, we illustrate that deep survival models can successfully transfer information across diseases to improve prognostic accuracy. We provide an open-source software implementation of this framework called SurvivalNet that enables automatic training, evaluation and interpretation of deep survival models.

Ductal Carcinoma in Situ: Quantitative Preoperative Breast MR Imaging Features Associated with Recurrence after Treatment

Purpose To investigate whether specific imaging features on breast magnetic resonance (MR) images are associated with ductal carcinoma in situ (DCIS) recurrence risk after definitive treatment. Materials and Methods Patients with DCIS who underwent preoperative dynamic contrast material-enhanced (DCE) MR imaging between 2004 and 2014 with ipsilateral recurrence more than 6 months after definitive surgical treatment were retrospectively identified. For each patient, a control subject with DCIS that did not recur was identified and matched on the basis of clinical, histopathologic, and treatment features known to affect recurrence risk. On DCE MR images, lesion characteristics (longest diameter, functional tumor volume [FTV], peak percentage enhancement [PE], peak signal enhancement ratio [SER], and washout fraction) and normal tissue features (background parenchymal enhancement [BPE] volume, mean BPE) were quantitatively measured. MR imaging features were compared between patients and control subjects by using the Wilcoxon signed-rank test, with adjustment for multiple comparisons. Results Of 415 subjects with DCIS who underwent preoperative MR imaging, 14 experienced recurrence and 11 had an identifiable matching control subject (final cohort, 11 patients and 11 control subjects). Median time to recurrence was 14 months, and median follow-up for control subjects was 102 months. When compared with matched control subjects, patients with DCIS recurrence exhibited significantly greater FTV (median, 9.3 cm³ vs 1.3 cm³, P = .01), lesion peak SER (median, 1.7 vs 1.2; P = .03), and mean BPE (median, 58.3% vs 41.1%; P = .02). Conclusion Quantitative lesion and normal breast tissue characteristics at preoperative MR imaging in women with newly diagnosed DCIS show promise for association with breast cancer recurrence after treatment. ^© RSNA, 2017.

Tissue-based biomarkers in prostate cancer

INTRODUCTION

Prostate cancer is a heterogeneous disease. Existing risk stratification tools based on standard clinlicopathologic variables (prostate specific antigen [PSA], Gleason score, and tumor stage) provide a modest degree of predictive ability. Advances in high-throughput sequencing has led to the development of several novel tissue-based biomarkers that can improve prognostication in prostate cancer management.

AREAS COVERED

The authors review commercially-available, tissue-based biomarker assays that improve upon existing risk-stratification tools in several areas of prostate cancer management, including the appropriateness of active surveillance and aiding in decision making regarding the use of adjuvant therapy. Additionally, some of the obstacles to the widespread adoption of these biomarkers and discuss several investigational sources of new biomarkers are discussed.

EXPERT COMMENTARY

Work is ongoing to answer pertinent clinical questions in prostate cancer management including which patients should undergo biopsy, active surveillance, receive adjuvant therapy, and what systemic therapy is best in the first-line. Incorporation into novel biomarkers may allow for the incorporation of a 'personalized' approach to management. Further validation will be required and questions of cost must be considered before wide scale adoption of these biomarkers. Tumor heterogeneity may impose a ceiling on the prognostic ability of biomarkers using currently available techniques.

Paradigm Shift toward Reducing Overtreatment of Ductal Carcinoma In Situ of Breast

The prevalence of ductal carcinoma in situ (DCIS) of the breast has increased substantially after the introduction of breast cancer screening programs, although the clinical effects of early DCIS detection and treatment remain unclear. The standard treatment for DCIS has involved local breast-conserving surgery (BCS) followed by radiotherapy (RT) or total mastectomy with/without endocrine therapy, and the choice of local treatment is not usually based on clinicopathologic or biological factors. However, we have investigated the effectiveness of local treatment using breast surgery and RT using Surveillance, Epidemiology, and End Results data, and found that the effectiveness of breast surgery was modified by the nuclear grade. Furthermore, breast cancer-specific survival was identical between patients with low-grade DCIS who did and did not undergo surgery. Moreover, we found that RT after BCS for DCIS was only associated with a survival benefit among patients with risk factors for local recurrence, such as nuclear grade, age, and tumor size. Ongoing clinical trials and translational research have attempted to develop a treatment strategy that prevents the overdiagnosis and overtreatment of low-risk DCIS, as well as a biology-based treatment strategy for using targeted therapy. Therefore, to develop a tailored treatment strategy for DCIS, we need to identify molecular and biological classifications based on the results from translational research, national databases, and clinical trials.

Comparison of HER2 amplification status among breast cancer subgroups offers new insights in pathways of breast cancer progression

Although the prognostic and predictive significance of human epidermal growth factor receptor 2 (HER2) in invasive breast cancer is well established, its role in ductal carcinoma in situ (DCIS) remains unclear. Reports on combined evaluation of both HER2 protein expression and HER2 amplification status in pure DCIS and DCIS adjacent to invasive ductal carcinoma (i.e., admixed DCIS) are scarce. In this study, immunohistochemistry and fluorescence in situ hybridization (FISH) were used to assess HER2 status in 72 cases of pure DCIS, 73 cases of DCIS admixed with invasive ductal carcinoma (IDC), and 60 cases of pure IDC. HER2 copy number-based amplification was present in 49% of pure DCIS, 16% of admixed DCIS, 18% of admixed IDC, and 8% of pure IDC. Amplified pure DCIS with clusters of HER2 signals showed a significantly lower HER2 copy number than amplified admixed DCIS with clusters. Whereas pure DCIS and admixed DCIS presented significant differences, the in situ and invasive component of admixed tumors showed striking similarities regarding mean HER2 and chromosome 17 centromere (CEP17) copy number, grade, and estrogen and progesterone receptor expression. The discrepant prevalence of HER2 amplification among breast cancer subgroups indirectly suggests that HER2 may not play a crucial role in the transition of in situ to invasive breast cancer. The similarities in HER2 amplification status between the in situ and invasive component of admixed tumors hint at a common biological pathway for both components. Our data support the theory that pure DCIS, pure IDC, and admixed lesions have a common progenitor, but can progress as separate lineages.

Clinical use of the Oncotype DX genomic test to guide treatment decisions for patients with invasive breast cancer

Implementation of the Oncotype DX assay has led to a change in the manner in which chemotherapy is utilized in patients with early stage, estrogen receptor (ER)-positive, node-negative breast cancer; ensuring that patients at highest risk of recurrence are prescribed systemic treatment, while at the same time sparing low-risk patients potential adverse events from therapy unlikely to influence their survival. This test generates a recurrence score between 0 and 100, which correlates with probability of distant disease recurrence. Patients with low-risk recurrence scores (0–17) are unlikely to derive significant survival benefit with adjuvant chemotherapy and hormonal agents derived from using adjuvant hormonal therapy only. Conversely, adjuvant chemotherapy has been shown to significantly improve survival in patients with high-risk recurrence scores (≥31). Trials are ongoing to determine how best to manage patients with recurrence scores in the intermediate range. This review outlines the introduction and impact of Oncotype DX testing on practice; ongoing clinical trials investigating its utility; and challenging clinical scenarios where the absolute recurrence score may require careful interpretation. We also performed a bibliometric analysis of publications on the topics of breast cancer and Oncotype DX as a surrogate marker of acceptability and incorporation of the assay into the management of patients with breast cancer.

Treatment of low-risk ductal carcinoma in situ: is nothing better than something?

The heterogeneous nature of ductal carcinoma in situ has been emphasised by data for breast-cancer screening that show substantial increases in the detection of early-stage non-invasive breast cancer but no noteworthy change in the incidence of invasive and distant metastatic disease. Indolent non-progressive forms of ductal carcinoma in situ are managed according to similar surgical strategies as high-risk disease, with extent of resection dictated by radiological and pathological estimates of tumour dimensions. Although adjuvant treatments might be withheld for low-risk lesions, surgical treatments incur potential morbidity, especially when mastectomy and breast reconstruction are done for widespread low-grade or intermediate-grade ductal carcinoma in situ. Low rates of deaths from breast cancer coupled with overdiagnosis within screening programmes have prompted a fundamental rethink of approaches to the management of both low-risk and high-risk ductal carcinoma in situ. Changes include active surveillance for low-risk lesions and a watchful waiting policy with intervention when invasive local recurrence after breast-conserving surgery is detected. Prediction of ipsilateral invasive recurrence is likely to be improved by integration of molecular biomarkers with conventional histopathological parameters. Moreover, further genetic interrogation of ductal carcinoma in situ might lead to a reclassification of some low-grade lesions as non-cancerous entities.

The diagnostic challenge of low-grade ductal carcinoma in situ

BACKGROUND

Diagnostic agreement among pathologists is 84% for ductal carcinoma in situ (DCIS). Studies of interpretive variation according to grade are limited.

METHODS

A national sample of 115 pathologists interpreted 240 breast pathology test set cases in the Breast Pathology Study and their interpretations were compared to expert consensus interpretations. We assessed agreement of pathologists' interpretations with a consensus reference diagnosis of DCIS dichotomised into low- and high-grade lesions. Generalised estimating equations were used in logistic regression models of rates of under- and over-interpretation of DCIS by grade.

RESULTS

We evaluated 2097 independent interpretations of DCIS (512 low-grade DCIS and 1585 high-grade DCIS). Agreement with reference diagnoses was 46% (95% confidence interval [CI] 42-51) for low-grade DCIS and 83% (95% CI 81-86) for high-grade DCIS. The proportion of reference low-grade DCIS interpretations over-interpreted by pathologists (i.e. categorised as either high-grade DCIS or invasive cancer) was 23% (95% CI 19-28); 30% (95% CI 26-34) were interpreted as a lower diagnostic category (atypia or benign proliferative). Reference high-grade DCIS was under-interpreted in 14% (95% CI 12-16) of observations and only over-interpreted 3% (95% CI 2-4).

CONCLUSION

Grade is a major factor when examining pathologists' variability in diagnosing DCIS, with much lower agreement for low-grade DCIS cases compared to high-grade. These findings support the hypothesis that low-grade DCIS poses a greater interpretive challenge than high-grade DCIS, which should be considered when developing DCIS management strategies.

Improving Therapeutic Ratios with the Oncotype DX® Ductal Carcinoma In Situ (DCIS) Score

Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer comprising nearly 25% of breast cancer diagnoses in the mammographic era. Current guidelines recommend breast-conserving surgery followed by adjuvant radiotherapy; however, controversy exists regarding the appropriateness of these recommendations. Some women with DCIS will never recur, which raises the concern of over-treatment. Conversely, a small number of women will develop invasive recurrences, raising concerns of under-treatment. Currently, several clinical and pathologic factors have been identified as prognostic markers for recurrence; however, these variables alone have been unable to identify low-risk and high-risk subgroups. The Oncotype DX® DCIS score is a multigene assay which allows for the addition of molecular information to traditional clinical and pathologic factors to help guide treatment decisions. Here, we present two case examples illustrating the use of the Oncotype DCIS score in clinical practice.

Current treatment trends and the need for better predictive tools in the management of ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) of the breast represents a group of heterogeneous non-invasive lesions the incidence of which has risen dramatically since the advent of mammography screening. In this review we summarise current treatment trends and up-to-date results from clinical trials studying surgery and adjuvant therapy alternatives, including the recent consensus on excision margin width and its role in decision-making for post-excision radiotherapy. The main challenge in the clinical management of DCIS continues to be the tailoring of treatment to individual risk, in order to avoid the over-treatment of low-risk lesions or under-treatment of DCIS with higher risk of recurring or progressing into invasion. While studies estimate that only about 40% of DCIS would become invasive if untreated, heterogeneity and complex natural history have prevented adequate identification of these higher-risk lesions. Here we discuss attempts to develop prognostic tools for the risk stratification of DCIS lesions and their limitations. Early results of a UK-wide audit of DCIS management (the Sloane Project) have also demonstrated a lack of consistency in treatment. In this review we offer up-to-date perspectives on current treatment and prediction of DCIS, highlighting the pressing clinical need for better prognostic indices. Tools integrating both clinical and histopathological factors together with molecular biomarkers may hold potential for adequate stratification of DCIS according to risk. This could help develop standardised practices for optimal management of patients with DCIS, improving clinical outcomes while providing only the amount of therapy required for each individual patient.

Effect of Referral Patterns and Treatment Type on Oncologic Outcomes for Women with Ductal Carcinoma In Situ

Objective

Management of ductal carcinoma in situ (DCIS) remains controversial. This study examined long-term outcomes in a population-based cohort of patients with pure DCIS treated with breast-conserving surgery (BCS) alone, BCS + radiotherapy (RT), and mastectomy. Outcomes were compared between patients referred versus not referred for oncologic assessment after definitive surgery.

Materials and methods

Subjects were 2575 women diagnosed between 1985 and 1999. Data from several electronic databases were linked and analyzed. Outcomes were invasive local recurrence-free survival (ILRFS), mastectomy-free survival (MFS), breast cancer-specific survival (BCSS), and overall survival (OS).

Results

Median follow-up time was 9.8 years. Overall, 56% (n = 1448) of subjects were referred to a cancer centre. Factors associated with non-referral were older age, comorbidities, and travel distance. Ten-year MFS, BCSS, and OS were higher among referred patients (all p ≤ 0.001). In cohorts treated with BCS alone (n = 1314) vs. BCS + RT (n = 510) vs. mastectomy (n = 751), 10-year ILRFS were 93.7% vs. 96.6% vs. 97.7%, (p < 0.001) and BCSS were 97.6% vs. 99.8% vs. 98.6%, (p = 0.01). Corresponding rates of ipsilateral invasive breast relapse at 10 years were 6.3% after BCS alone, 3.4% after BCS + RT, and 2.3% after mastectomy (p < 0.001). On multivariable analysis, factors associated with improved ILRFS were older age at diagnosis, low comorbidity score, absence of comedo histology, mastectomy, and post-BCS RT.

Conclusion

Patients with DCIS referred for oncologic assessment were more likely to undergo post-BCS RT, resulting in lower mastectomy and higher survival rates compared to non-referred patients. Patients with significant comorbidities were less likely to be referred and experienced lower ILRFS and BCSS. Referral for multidisciplinary oncologic assessment after surgery is warranted to individualize management and optimize outcomes for patients with DCIS.

Molecular Testing in Breast Cancer: A Guide to Current Practices

CONTEXT

-Molecular diagnostics play a role in the management of many cancers, including breast cancer.

OBJECTIVE

-To provide an update on molecular testing in current clinical practice, targeted at practicing pathologists who are not breast cancer specialists.

DATA SOURCES

-This study is a narrative literature review.

CONCLUSIONS

-In addition to routine hormone (estrogen and progesterone) receptor testing, new and recurrent tumors are tested for HER2 amplification by in situ hybridization or overexpression by immunohistochemistry. Intrinsic subtyping of tumors represents a fundamental advance in our understanding of breast cancer biology, but currently it has an indirect role in patient management. Clinical next-generation sequencing (tumor profiling) is increasingly used to identify potentially actionable mutations in tumor tissue. Multianalyte assays with algorithmic analysis, including MammaPrint, Oncotype DX, and Prosigna, play a larger role in breast cancer than in many other malignancies. Given that a proportion of breast cancers are familial, testing of nontumor tissue for cancer predisposition mutations also plays a role in breast cancer care.

Adjuvant therapy in patients with ductal carcinoma in situ of the breast: The Pandora's box

Most patients with ductal carcinoma in situ of the breast (DCIS) are eligible for breast conservation treatment. The key management decision is whether to add radiotherapy and/or endocrine therapy to minimize the risk of a subsequent recurrence. Recent analyses indicating a lack of benefit in terms of breast cancer-associated mortality have suggested that more conservative approaches, omitting adjuvant therapy or even surgery, may be advisable in selected patients. These mortality observations are directly influenced by widespread use of mammographic screening which has opened a Pandora's box of subclinical DCIS and early invasive lesions. Confusion as to how aggressively such possibly indolent lesions should be treated has led to misunderstandings among patients and medical professionals. While awaiting further prospective evidence from clinical trials, we endorse an active treatment of DCIS as the standard of care. Our rationale is twofold: invasive recurrences are associated with an increase in breast cancer mortality, which is not the only relevant endpoint for DCIS. The benefit of complete surgical excision, adjuvant radiotherapy and endocrine treatment in preventing recurrence and invasive progression has been demonstrated in DCIS. The challenge now is how to identify DCIS patients who will not progress to invasive carcinoma even without complete excision and, at the other extreme, those patients at the highest risk who require mastectomy for local control. The current controversies over whether and which adjuvant therapy should be implemented can at least in part be addressed by developing effective doctor-patient communications that enable mutual understanding about the management of this biologically heterogeneous disease.

Association between access to accelerated partial breast irradiation and use of adjuvant radiotherapy

BACKGROUND

The current study was performed to determine whether access to facilities performing accelerated partial breast irradiation (APBI) is associated with differences in the use of adjuvant radiotherapy (RT).

METHODS

Using the National Cancer Data Base, the authors performed a retrospective study of women aged ≥50 years who were diagnosed with early-stage breast cancer between 2004 and 2013 and treated with breast-conserving surgery (BCS). Facilities performing APBI in ≥10% of their eligible patients within a given year were defined as APBI facilities whereas those not performing APBI were defined as non-APBI facilities. All other facilities were excluded. The authors identified independent factors associated with RT use using multivariable logistic regression with clustering in the overall sample as well as in subsets of patients with standard-risk invasive cancer, low-risk invasive cancer, and ductal carcinoma in situ.

RESULTS

Among 222,544 patients, 76.6% underwent BCS plus RT and 23.4% underwent BCS alone. The likelihood of RT receipt in the overall sample did not appear to differ significantly between APBI and non-APBI facilities (adjusted odds ratio [AOR], 1.02; P = .61). Subgroup multivariable analysis demonstrated that among patients with standard-risk invasive cancer, there was no association between evaluation at an APBI facility and receipt of RT (AOR, 0.98; P = .69). However, patients with low-risk invasive cancer were found to be significantly more likely to receive RT (54.4% vs 59.5%; AOR, 1.22 [P<.001]), whereas patients with ductal carcinoma in situ were less likely to receive RT (56.9% vs 55.3%; AOR, 0.89 [P = .04]) at APBI facilities.

CONCLUSIONS

Patients who were eligible for observation were more likely to receive RT in APBI facilities but no difference was observed among patients with standard-risk invasive cancer who would most benefit from RT. Cancer 2017;123:502-511. © 2016 American Cancer Society.

Recurrence outcomes after omission of postoperative radiotherapy following breast-conserving surgery for ductal carcinoma in situ of the breast: a multicenter, retrospective study in Korea (KROG 16-02)

PURPOSE

To evaluate the loco-regional recurrence (LRR) rate after breast-conserving surgery without postoperative radiotherapy (RT) for ductal carcinoma in situ (DCIS) of the breast.

METHODS

Between 2000 and 2010, 311 DCIS patients from 9 institutions were analyzed retrospectively. The median age was 47 (range, 20-82). The median tumor size was 7 mm (range, 0.01-76). Margin width was <1 cm in 85 patients (27.3%), and nuclear grade was high in 37 patients (11.9%). Two hundred and three patients (65.3%) received tamoxifen.

RESULTS

With a median follow-up of 74 months (range, 5-189), there were 11 local recurrences (invasive carcinoma in 6 and DCIS in 5) and 1 regional recurrence. The 7-year LRR rate was 3.8%. On univariate analysis, age and margin width were significant risk factors influencing LRR (p = 0.017 and 0.014, respectively). When age and margin width were combined among 211 patients whose margin width were available, the 7-year LRR rates were as follows (p < 0.001): (1) 0% in patients with age >50 years and any margin width status (n = 64), (2) 1.2% in age ≤50 years and margin width ≥1 cm (n = 93), (3) 13.1% in age ≤50 years and margin width <1 cm (n = 54).

CONCLUSIONS

The LRR rate was very low in selected DCIS patients treated with breast-conserving surgery without postoperative RT. However, adjuvant RT should be considered for those with age ≤50 years and margin width <1 cm.

Catalog of genetic progression of human cancers: breast cancer

With the rapid development of next-generation sequencing, deeper insights are being gained into the molecular evolution that underlies the development and clinical progression of breast cancer. It is apparent that during evolution, breast cancers acquire thousands of mutations including single base pair substitutions, insertions, deletions, copy number aberrations, and structural rearrangements. As a consequence, at the whole genome level, no two cancers are identical and few cancers even share the same complement of "driver" mutations. Indeed, two samples from the same cancer may also exhibit extensive differences due to constant remodeling of the genome over time. In this review, we summarize recent studies that extend our understanding of the genomic basis of cancer progression. Key biological insights include the following: subclonal diversification begins early in cancer evolution, being detectable even in in situ lesions; geographical stratification of subclonal structure is frequent in primary tumors and can include therapeutically targetable alterations; multiple distant metastases typically arise from a common metastatic ancestor following a "metastatic cascade" model; systemic therapy can unmask preexisting resistant subclones or influence further treatment sensitivity and disease progression. We conclude the review by describing novel approaches such as the analysis of circulating DNA and patient-derived xenografts that promise to further our understanding of the genomic changes occurring during cancer evolution and guide treatment decision making.

The Relationships between HER2 Overexpression and DCIS Characteristics

The aim of this study was to demonstrate the correlation between human epidermal growth factor receptor 2 (HER2) overexpression and some poor prognosis factors in patients affected by ductal carcinoma in situ (DCIS). We evaluated 48 cases of DCIS, divided into two groups according to HER2 amplification status. Nuclear grade and "cancerization of lobules" were determined within primary DCIS and Ki67, estrogen receptor (ER), PR, and HER2 expression was established using immunohistochemistry. The histopathological variables in HER2-positive and in HER2-negative patients were compared to determine the recurrence risk. We also considered the median age at the time of surgery according to HER2 status. There were 11 recurrences (23%), 6 DCIS (55%), and 5 invasive cancer (45%). In an 8-year-long median follow-up, we hypothesized high risk of recurrence in HER2-positive DCIS. Patients with HER2-positive DCIS were younger than HER2-negative ones (p = 0.002). HER2-positive DCIS was also related to histopathological predictors of recurrence such as high nuclear grade (p < 0.001), high Ki67 expression (p = 0.003), low ER and PgR levels (p < 0.001), and the presence of "cancerization of lobules" (p < 0.049). Our trial suggests that HER2 amplification in primary DCIS is identified more frequently in younger patients and hypothesizes high risk of recurrence in HER2-positive DCIS related to histopathological predictors of overall relapse as high nuclear grade, high Ki67 expression, low ER and PgR levels, and the presence of "cancerization of lobules." In HER2-positive DCIS, other variables of recurrence risk are compared to HER2-negative lesions, without statistical significance. Our results show that HER2 testing might suggest clinicians the optimal treatment of patients with DCIS.

How could breast cancer molecular features contribute to locoregional treatment decision making?

Systemic treatments are tailored to breast cancer (BC) heterogeneity, which is not yet taken into account for radiotherapy (RT) personalization. The primary objective of this review is to summarize existing data suggesting BC subtypes and genetic assays are prognostic and predictive biomarkers useful for RT decision-making and to provide implications for their incorporation into future translational and clinical research. The evidence suggesting that BC subtypes also exhibit distinct "locoregional recurrence (LRR)" patterns is retrospective but consistent and validated in over fifteen studies. The HER-2 positive and triple negative subtypes are the most susceptible to locoregional failure. The high risk of the HER-2 positive subtype can be reversed with trastuzumab administration. Very little is known on the subtypes' intrinsic radiosensitivity properties. Genetic assays have assessed retrospectively signatures' prognostic and predictive value in patients' cohorts (several coming from prospective studies) for LRR risk and radiotherapy (RT) benefit. Further confirmation is needed before their introduction into clinical routine. Evidence on the use of molecular biomarkers for adjuvant RT tailoring is emerging but needs validation and introduction into prospective studies. The plethora of modern RT options (partial breast irradiation, hypofractionation), as well as recent evidence pointing towards more extensive radiotherapy, demand introduction of biological features into clinical trials to improve therapeutic decisions. Open questions, such as tailoring of irradiation after neo-adjuvant chemotherapy in complete responders and the understanding of the interplay between local control, systemic recurrence and survival given modern systemic treatments, need to be addressed under the prism of biology within this heterogeneous disease. Intrinsic radiobiological properties within this heterogeneity need to be highlighted in order to further improve outcomes.

Genome evolution in ductal carcinoma in situ: invasion of the clones

Ductal carcinoma in situ (DCIS) is the most frequently diagnosed early-stage breast cancer. Only a subset of patients progress to invasive ductal carcinoma (IDC), and this presents a formidable clinical challenge for determining which patients to treat aggressively and which patients to monitor without therapeutic intervention. Understanding the molecular and genomic basis of invasion has been difficult to study in DCIS cancers due to several technical obstacles, including low tumour cellularity, lack of fresh-frozen tissues, and intratumour heterogeneity. In this review, we discuss the role of intratumour heterogeneity in the progression of DCIS to IDC in the context of three evolutionary models: independent lineages, evolutionary bottlenecks, and multiclonal invasion. We examine the evidence in support of these models and their relevance to the diagnosis and treatment of patients with DCIS. We also discuss how emerging technologies, such as single-cell sequencing, STAR-FISH, and imaging mass spectrometry, are likely to provide new insights into the evolution of this enigmatic disease. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Identifying progression predictors of breast ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) refers to neoplastic epithelial cells proliferating within the mammary ducts of the breast, which have not breached the basement membrane nor invaded surrounding tissues. Traditional thinking holds that DCIS represents an early step in a linear progression towards invasive ductal carcinoma (IDC). However, as only approximately half of DCIS cases progress to IDC, important questions around the key determinants of malignant progression need to be answered. Recent studies have revealed that molecular differences between DCIS and IDC cells are not found at the genomic level; instead, altered patterns of gene expression and post-translational regulation lead to distinct transcriptomic and proteomic profiles. Therefore, understanding malignant progression will require a different approach that takes into account the diverse tumour cell extrinsic factors driving changes in tumour cell gene expression necessary for the invasive phenotype. Here, we review the roles of the tumour stroma (including mesenchymal cells, immune cells and the extracellular matrix) and myoepithelial cells in malignant progression and make a case for a more integrated approach to the study and assessment of DCIS and its progression, or lack thereof, to invasive disease.

Society of Surgical Oncology-American Society for Radiation Oncology-American Society of Clinical Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Ductal Carcinoma In Situ

Background Controversy exists regarding the optimal negative margin width for ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and whole-breast irradiation (WBRT). Methods A multidisciplinary consensus panel used a meta-analysis of margin width and ipsilateral breast tumor recurrence (IBTR) from a systematic review of 20 studies including 7883 patients and other published literature as the evidence base for consensus. Results Negative margins halve the risk of IBTR compared with positive margins defined as ink on DCIS. A 2 mm margin minimizes the risk of IBTR compared with smaller negative margins. More widely clear margins do not significantly decrease IBTR compared with 2 mm margins. Negative margins less than 2 mm alone are not an indication for mastectomy, and factors known to impact rates of IBTR should be considered in determining the need for re-excision. Conclusion The use of a 2 mm margin as the standard for an adequate margin in DCIS treated with WBRT is associated with low rates of IBTR and has the potential to decrease re-excision rates, improve cosmetic outcome, and decrease health care costs. Clinical judgment should be used in determining the need for further surgery in patients with negative margins < 2 mm.

OPTIMA prelim: a randomised feasibility study of personalised care in the treatment of women with early breast cancer

BACKGROUND

There is uncertainty about the chemotherapy sensitivity of some oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers. Multiparameter assays that measure the expression of several tumour genes simultaneously have been developed to guide the use of adjuvant chemotherapy for this breast cancer subtype. The assays provide prognostic information and have been claimed to predict chemotherapy sensitivity. There is a dearth of prospective validation studies. The Optimal Personalised Treatment of early breast cancer usIng Multiparameter Analysis preliminary study (OPTIMA prelim) is the feasibility phase of a randomised controlled trial (RCT) designed to validate the use of multiparameter assay directed chemotherapy decisions in the NHS.

OBJECTIVES

OPTIMA prelim was designed to establish the acceptability to patients and clinicians of randomisation to test-driven treatment assignment compared with usual care and to select an assay for study in the main RCT.

DESIGN

Partially blinded RCT with adaptive design.

SETTING

Thirty-five UK hospitals.

PARTICIPANTS

Patients aged ≥ 40 years with surgically treated ER-positive HER2-negative primary breast cancer and with 1-9 involved axillary nodes, or, if node negative, a tumour at least 30 mm in diameter.

INTERVENTIONS

Randomisation between two treatment options. Option 1 was standard care consisting of chemotherapy followed by endocrine therapy. In option 2, an Oncotype DX(®) test (Genomic Health Inc., Redwood City, CA, USA) performed on the resected tumour was used to assign patients either to standard care [if 'recurrence score' (RS) was > 25] or to endocrine therapy alone (if RS was ≤ 25). Patients allocated chemotherapy were blind to their randomisation.

MAIN OUTCOME MEASURES

The pre-specified success criteria were recruitment of 300 patients in no longer than 2 years and, for the final 150 patients, (1) an acceptance rate of at least 40%; (2) recruitment taking no longer than 6 months; and (3) chemotherapy starting within 6 weeks of consent in at least 85% of patients.

RESULTS

Between September 2012 and 3 June 2014, 350 patients consented to join OPTIMA prelim and 313 were randomised; the final 150 patients were recruited in 6 months, of whom 92% assigned chemotherapy started treatment within 6 weeks. The acceptance rate for the 750 patients invited to participate was 47%. Twelve out of the 325 patients with data (3.7%, 95% confidence interval 1.7% to 5.8%) were deemed ineligible on central review of receptor status. Interviews with researchers and recordings of potential participant consultations made as part of the integral qualitative recruitment study provided insights into recruitment barriers and led to interventions designed to improve recruitment. Patient information was changed as the result of feedback from three patient focus groups. Additional multiparameter analysis was performed on 302 tumour samples. Although Oncotype DX, MammaPrint(®)/BluePrint(®) (Agendia Inc., Irvine, CA, USA), Prosigna(®) (NanoString Technologies Inc., Seattle, WA, USA), IHC4, IHC4 automated quantitative immunofluorescence (AQUA(®)) [NexCourse BreastTM (Genoptix Inc. Carlsbad, CA, USA)] and MammaTyper(®) (BioNTech Diagnostics GmbH, Mainz, Germany) categorised comparable numbers of tumours into low- or high-risk groups and/or equivalent molecular subtypes, there was only moderate agreement between tests at an individual tumour level (kappa ranges 0.33-0.60 and 0.39-0.55 for tests providing risks and subtypes, respectively). Health economics modelling showed the value of information to the NHS from further research into multiparameter testing is high irrespective of the test evaluated. Prosigna is currently the highest priority for further study.

CONCLUSIONS

OPTIMA prelim has achieved its aims of demonstrating that a large UK clinical trial of multiparameter assay-based selection of chemotherapy in hormone-sensitive early breast cancer is feasible. The economic analysis shows that a trial would be economically worthwhile for the NHS. Based on the outcome of the OPTIMA prelim, a large-scale RCT to evaluate the clinical effectiveness and cost-effectiveness of multiparameter assay-directed chemotherapy decisions in hormone-sensitive HER2-negative early breast would be appropriate to take place in the NHS.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN42400492.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 10. See the NIHR Journals Library website for further project information. The Government of Ontario funded research at the Ontario Institute for Cancer Research. Robert C Stein received additional support from the NIHR University College London Hospitals Biomedical Research Centre.

Characterizing the immune microenvironment in high-risk ductal carcinoma in situ of the breast

PURPOSE

The recent increase in the incidence of ductal carcinoma in situ (DCIS) has sparked debate over the classification and treatment of this disease. Although DCIS is considered a precursor lesion to invasive breast cancer, some DCIS may have more or less risk than is realized. In this study, we characterized the immune microenvironment in DCIS to determine if immune infiltrates are predictive of recurrence.

METHODS

Fifty-two cases of high-grade DCIS (HG-DCIS), enriched for large lesions and a history of recurrence, were age matched with 65 cases of non-high-grade DCIS (nHG-DCIS). Immune infiltrates were characterized by single- or dual-color staining of FFPE sections for the following antigens: CD4, CD8, CD20, FoxP3, CD68, CD115, Mac387, MRC1, HLA-DR, and PCNA. Nuance multispectral imaging software was used for image acquisition. Protocols for automated image analysis were developed using CellProfiler. Immune cell populations associated with risk of recurrence were identified using classification and regression tree analysis.

RESULTS

HG-DCIS had significantly higher percentages of FoxP3⁺ cells, CD68⁺ and CD68⁺PCNA⁺ macrophages, HLA-DR⁺ cells, CD4⁺ T cells, CD20⁺ B cells, and total tumor infiltrating lymphocytes compared to nHG-DCIS. A classification tree, generated from 16 immune cell populations and 8 clinical parameters, identified three immune cell populations associated with risk of recurrence: CD8⁺HLADR⁺ T cells, CD8⁺HLADR^- T cells, and CD115⁺ cells.

CONCLUSION

These findings suggest that the tumor immune microenvironment is an important factor in identifying DCIS cases with the highest risk for recurrence and that manipulating the immune microenvironment may be an efficacious strategy to alter or prevent disease progression.

Ductal carcinoma in situ - update on risk assessment and management

Ductal carcinoma in situ (DCIS) accounts for ~20-25% of breast cancers. While DCIS is not life-threatening, it may progress to invasive carcinoma over time, and treatment intended to prevent invasive progression may itself cause significant morbidity. Accurate risk assessment is therefore necessary to avoid over- or undertreatment of an individual patient. In this review we will outline the evidence for current management of DCIS, discuss approaches to DCIS risk assessment and challenges facing identification of novel DCIS biomarkers.

Clinical Utility of the 12-Gene DCIS Score Assay: Impact on Radiotherapy Recommendations for Patients with Ductal Carcinoma In Situ

Objective

The aim of this study was to determine the impact of the results of the 12-gene DCIS Score assay on (i) radiotherapy recommendations for patients with pure ductal carcinoma in situ (DCIS) following breast-conserving surgery (BCS), and (ii) patient decisional conflict and state anxiety.

Methods

Thirteen sites across the US enrolled patients (March 2014–August 2015) with pure DCIS undergoing BCS. Prospectively collected data included clinicopathologic factors, physician estimates of local recurrence risk, DCIS Score results, and pre-/post-assay radiotherapy recommendations for each patient made by a surgeon and a radiation oncologist. Patients completed pre-/post-assay decisional conflict scale and state-trait anxiety inventory instruments.

Results

The analysis cohort included 127 patients: median age 60 years, 80 % postmenopausal, median size 8 mm (39 % ≤5 mm), 70 % grade 1/2, 88 % estrogen receptor-positive, 75 % progesterone receptor-positive, 54 % with comedo necrosis, and 18 % multifocal. Sixty-six percent of patients had low DCIS Score results, 20 % had intermediate DCIS Score results, and 14 % had high DCIS Score results; the median result was 21 (range 0–84). Pre-assay, surgeons and radiation oncologists recommended radiotherapy for 70.9 and 72.4 % of patients, respectively. Post-assay, 26.4 % of overall recommendations changed, including 30.7 and 22.0 % of recommendations by surgeons and radiation oncologists, respectively. Among patients with confirmed completed questionnaires (n = 32), decision conflict (p = 0.004) and state anxiety (p = 0.042) decreased significantly from pre- to post-assay.

Conclusions

Individualized risk estimates from the DCIS Score assay provide valuable information to physicians and patients. Post-assay, in response to DCIS Score results, surgeons changed treatment recommendations more often than radiation oncologists. Further investigation is needed to better understand how such treatment changes may affect clinical outcomes.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-016-5583-7) contains supplementary material, which is available to authorized users.

Updates in the treatment of ductal carcinoma in situ of the breast

PURPOSE OF REVIEW

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically diagnosed breast cancers. Currently, there is a trend to consider DCIS as a lesion for which treatment deescalation is advocated to avoid overtreatment, that is, radiotherapy in addition to breast-conserving surgery or even surgery at all.

RECENT FINDINGS

The long-term follow-up updates of the four first-generation randomized trials comparing lumpectomy with and without radiation therapy have confirmed that radiation halves the local failure rates. However, radiotherapy is not associated with a survival benefit just as affirmed by the recently published evaluation of the Surveillance, Epidemiology, and End Results registries database, including 108,196 women with DCIS. Nevertheless, the risk of dying of breast cancer increases about factor 18 after experience of an invasive local recurrence. That means at least some DCIS have the potential to progress to a life threatening disease. At the same time, none of the recently updated prospective trials that tested the outcome after excision alone in low-risk DCIS achieved a 10-year local failure rate below 10%.

SUMMARY

DCIS is not a uniform disease. Its clinical behaviour is heterogeneous, but up to date no citeria are available that allow a precise identification of patients with low or very low progression risk who do not need irradiation. Therefore, excision followed by radiotherapy is still the standard of care in patients undergoing breast conservation. Promising new approaches for risk estimation have to be validated prospectively before their use in daily practice can be recommended.

Cost Effectiveness of the Oncotype DX DCIS Score for Guiding Treatment of Patients With Ductal Carcinoma In Situ

Purpose The Oncotype DX DCIS Score short form (DCIS Score) estimates the risk of an ipsilateral breast event (IBE) in patients with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery without adjuvant radiation therapy (RT). We determined the cost effectiveness of strategies using this test. Materials and Methods We developed a Markov model simulating 10-year outcomes for 60-year-old women eligible for the Eastern Cooperative Oncology Group E5194 study (cohort 1: low/intermediate-grade DCIS, ≤ 2.5 cm; cohort 2: high-grade DCIS, ≤ 1 cm) with each of five strategies: (1) no testing, no RT; (2) no testing, RT only for cohort 2; (3) no RT for low-grade DCIS, test for intermediate- and high-grade DCIS, RT for intermediate- or high-risk scores; (4) test all, RT for intermediate- or high-risk scores; and (5) no testing, RT for all. We used utilities and costs extracted from the literature and Medicare claims to determine incremental cost-effectiveness ratios and examined the number of women needed to irradiate per IBE prevented. Results No strategy using the DCIS Score was cost effective. The most cost-effective strategy (RT for none or RT for all) was sensitive to small differences between the utilities of receiving or not receiving RT and remaining without recurrence. The numbers needed to irradiate per IBE prevented were 10.5, 9.1, 7.5, and 13.1 for strategies 2 to 5, respectively, relative to strategy 1. Conclusion Strategies using the DCIS Score lowered the proportion of women undergoing RT per IBE prevented. However, no strategy incorporating the DCIS Score was cost effective. The cost effectiveness of RT was exquisitely utility sensitive, highlighting the importance of engaging patient preferences in this decision. Physicians should discuss trade-offs associated with omitting or adding adjuvant RT with each patient to maximize quality-of-life outcomes.