Molecular subtypes in ductal carcinoma in situ of the breast and their relation to prognosis: a population-based cohort study

Immune cell infiltrate in ductal carcinoma in situ and the risk of dying from breast cancer: case-control study

BACKGROUND

Studies identifying risk factors for death from breast cancer after ductal carcinoma in situ (DCIS) are rare. In this retrospective nested case-control study, clinicopathological factors in women treated for DCIS and who died from breast cancer were compared with those of patients with DCIS who were free from metastatic disease.

METHODS

The study included patients registered with DCIS without invasive carcinoma in Sweden between 1992 and 2012. This cohort was linked to the National Cause of Death Registry. Of 6964 women with DCIS, 96 were registered with breast cancer as cause of death (cases). For each case, up to four controls (318; women with DCIS, alive and without metastatic breast cancer at the time of death of the corresponding case) were selected randomly by incidence density sampling. Whole slides of tumour tissue were evaluated for DCIS grade, comedo necrosis, and intensity of periductal lymphocytic infiltrate. Composition of the immune cell infiltrate, expression of oestrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and proliferation marker Ki-67 were scored on tissue microarrays. Clinical information was obtained from medical records. Information on date, site, and histological characteristics of local and distant recurrences was obtained from medical records for both cases and controls.

RESULTS

Tumour tissue was analysed from 65 cases and 195 controls. Intense periductal lymphocytic infiltrate around DCIS was associated with an increased risk of later dying from breast cancer (OR 2.21. 95% c.i. 1.01 to 4.84). Tumours with more intense lymphocytic infiltrate had a lower T cell/B cell ratio. None of the other biomarkers correlated with increased risk of breast cancer death.

CONCLUSION

The immune response to DCIS may influence the risk of dying from breast cancer.

Critical Roles of SRC-3 in the Development and Progression of Breast Cancer, Rendering It a Prospective Clinical Target

Breast cancer (BCa) is the most frequently diagnosed malignant tumor in women and is also one of the leading causes of cancer-related death. Most breast tumors are hormone-dependent and estrogen signaling plays a critical role in promoting the survival and malignant behaviors of these cells. Estrogen signaling involves ligand-activated cytoplasmic estrogen receptors that translocate to the nucleus with various co-regulators, such as steroid receptor co-activator (SRC) family members, and bind to the promoters of target genes and regulate their expression. SRC-3 is a member of this family that interacts with, and enhances, the transcriptional activity of the ligand activated estrogen receptor. Although SRC-3 has important roles in normal homeostasis and developmental processes, it has been shown to be amplified and overexpressed in breast cancer and to promote malignancy. The malignancy-promoting potential of SRC-3 is diverse and involves both promoting malignant behavior of tumor cells and creating a tumor microenvironment that has an immunosuppressive phenotype. SRC-3 also inhibits the recruitment of tumor-infiltrating lymphocytes with effector function and promotes stemness. Furthermore, SRC-3 is also involved in the development of resistance to hormone therapy and immunotherapy during breast cancer treatment. The versatility of SRC-3 in promoting breast cancer malignancy in this way makes it a good target, and methodical targeting of SRC-3 probably will be important for the success of breast cancer treatment.

Subtypes of high-grade breast ductal carcinoma in situ (DCIS): incidence and potential clinical impact

OBJECTIVE

The purpose of this study was to investigate and classify the molecular subtypes of high-grade ductal carcinoma in situ (DCIS) and identify possible high-risk subtypes. The heterogenicity of DCIS with variable clinical and histopathological presentations has been recognized. Nevertheless, only histopathological grading and diameter are currently implemented in clinical decision-making following the diagnosis of DCIS. The molecular subtypes of DCIS and their IHC surrogate markers have not been defined in conventional treatment guidelines and recommendations. We applied the definitions of molecular subtypes according to the IHC surrogate markers defined for IBC and subclassified high-grade DCIS, accordingly.

METHODS

Histopathological specimens were collected, revised, and regraded from 494 patients diagnosed with DCIS between 1996 and 2018. Other in situ and papillary lesions observed in breast biopsies were excluded from this study. 357 high-grade DCIS cases were submitted to IHC analysis. The markers investigated were ER, PR, HER2, and Ki67.

RESULTS

45 cases were classified as grade 1, 19 as grade 2, and 430 as grade 3. Sixty patients with high-grade DCIS had an additional invasive component in the surgical specimen. Thirty-three patients were diagnosed with recurrent DCIS or invasive cancer (minimum one year after their primary DCIS diagnosis). The proportions of luminal A and luminal B HER2-negative subtypes varied depending on whether 2011 or 2013 St. Gallen Consensus Conference guidelines were adopted. Luminal A was the most prevalent subtype, according to both classifications. The luminal B HER2-positive subtype was found in 22.1% of cases, HER2-enriched subtype in 21.8%, and TPN subtype in 5.6%. There were strong indications that HER2-enriched subtype was significantly more frequent among DCIS with invasive component (p = 0.0169).

CONCLUSIONS

High-grade DCIS exhibits all the molecular subtypes previously identified in IBC, but with a somewhat different distribution in our cohort. HER2-enriched subtype is substantially related to the presence of an invasive component in DCIS; consequently, it is regarded as a high-risk entity.

Accurate genome-wide genotyping from archival tissue to explore the contribution of common genetic variants to pre-cancer outcomes

PURPOSE

The contribution of common genetic variants to pre-cancer progression is understudied due to long follow-up time, rarity of poor outcomes and lack of available germline DNA collection. Alternatively, DNA from diagnostic archival tissue is available, but its somatic nature, limited quantity and suboptimal quality would require an accurate cost-effective genome-wide germline genotyping methodology.

EXPERIMENTAL DESIGN

Blood and tissue DNA from 10 individuals were used to benchmark the accuracy of Single Nucleotide Polymorphisms (SNP) genotypes, Polygenic Risk Scores (PRS) or HLA haplotypes using low-coverage whole-genome sequencing (lc-WGS) and genotype imputation. Tissue-derived PRS were further evaluated for 36 breast cancer patients (11.7 years median follow-up time) diagnosed with DCIS and used to model the risk of Breast Cancer Subsequent Events (BCSE).

RESULTS

Tissue-derived germline DNA profiling resulted in accurate genotypes at common SNPs (blood correlation r2 > 0.94) and across 22 disease-related polygenic risk scores (PRS, mean correlation r = 0.93). Imputed Class I and II HLA haplotypes were 96.7% and 82.5% concordant with clinical-grade blood HLA haplotypes, respectively. In DCIS patients, tissue-derived PRS was significantly associated with BCSE (HR = 2, 95% CI 1.2-3.8). The top and bottom decile patients had an estimated 28% and 5% chance of BCSE at 10 years, respectively.

CONCLUSIONS

Archival tissue DNA germline profiling using lc-WGS and imputation, represents a cost and resource-effective alternative in the retrospective design of long-term disease genetic studies. Initial results in breast cancer suggest that common risk variants contribute to pre-cancer progression.

Elevated NRAS expression during DCIS is a potential driver for progression to basal-like properties and local invasiveness

BACKGROUND

Ductal carcinoma in situ (DCIS) is the most common type of in situ premalignant breast cancers. What drives DCIS to invasive breast cancer is unclear. Basal-like invasive breast cancers are aggressive. We have previously shown that NRAS is highly expressed selectively in basal-like subtypes of invasive breast cancers and can promote their growth and progression. In this study, we investigated whether NRAS expression at the DCIS stage can control transition from luminal DCIS to basal-like invasive breast cancers.

METHODS

Wilcoxon rank-sum test was performed to assess expression of NRAS in DCIS compared to invasive breast tumors in patients. NRAS mRNA levels were also determined by fluorescence in situ hybridization in patient tumor microarrays (TMAs) with concurrent normal, DCIS, and invasive breast cancer, and association of NRAS mRNA levels with DCIS and invasive breast cancer was assessed by paired Wilcoxon signed-rank test. Pearson's correlation was calculated between NRAS mRNA levels and basal biomarkers in the TMAs, as well as in patient datasets. RNA-seq data were generated in cell lines, and unsupervised hierarchical clustering was performed after combining with RNA-seq data from a previously published patient cohort.

RESULTS

Invasive breast cancers showed higher NRAS mRNA levels compared to DCIS samples. These NRAShigh lesions were also enriched with basal-like features, such as basal gene expression signatures, lower ER, and higher p53 protein and Ki67 levels. We have shown previously that NRAS drives aggressive features in DCIS-like and basal-like SUM102PT cells. Here, we found that NRAS-silencing induced a shift to a luminal gene expression pattern. Conversely, NRAS overexpression in the luminal DCIS SUM225 cells induced a basal-like gene expression pattern, as well as an epithelial-to-mesenchymal transition signature. Furthermore, these cells formed disorganized mammospheres containing cell masses with an apparent reduction in adhesion.

CONCLUSIONS

These data suggest that elevated NRAS levels in DCIS are not only a marker but can also control the emergence of basal-like features leading to more aggressive tumor activity, thus supporting the therapeutic hypothesis that targeting NRAS and/or downstream pathways may block disease progression for a subset of DCIS patients with high NRAS.

miR-145, miR-205 and miR-451: potential tumor suppressors involved in the progression of in situ to invasive carcinoma of the breast

BACKGROUND

MicroRNAs (miRNAs) control diverse biologic processes during tumor progression. This study was conducted to identify miRNAs that are implicated in progression of in situ to invasive breast cancer (IBC) and to evaluate their association with clinicopathological features of ductal carcinoma in situ (DCIS).

METHODS

We performed miRNA microarray analyses to find differentially expressed miRNAs between DCIS and IBC in a test set, and validated expression levels of selected miRNAs using a different set of tumors. Finally, we evaluated the relationship between clinicopathological features and the expression of selected miRNAs in DCIS samples.

RESULTS

We found that miR-145-5p, miR-205-5p and miR-451a are significantly down-regulated in IBC compared to DCIS in the whole group, and in the estrogen receptor (ER)-positive and ER-negative subgroups. In a validation set, miR-145, miR-205, and miR-451 also showed lower expression levels in IBC than in DCIS, irrespective of ER status. Moreover, their expression levels were significantly lower in the invasive component compared to the in situ component within same tumors. MiR-145, miR-205 and miR-451 commonly showed lower expression levels in DCIS with positive HER2 status and high Ki-67 proliferation index. Especially, miR-145 and miR-205 showed lower expression levels in DCIS with microinvasion, compared to pure DCIS. In addition, lower miR-205 expression level was associated with high nuclear grade, comedo type necrosis, and hormone receptor negativity.

CONCLUSIONS

Our study showed that miR-145, miR-205 and miR-451 expression decreased in IBC compared to DCIS, and their expression levels were low in DCIS with high-risk features for progression, implying their contributions in the progression of DCIS to invasive carcinoma as tumor suppressors.

Ductal Carcinoma In Situ of Breast: From Molecular Etiology to Therapeutic Management

Ductal carcinoma in situ (DCIS) makes up a majority of noninvasive breast cancer cases. DCIS is a neoplastic proliferation of epithelial cells within the ductal structure of the breast. Currently, there is little known about the progression of DCIS to invasive ductal carcinoma (IDC), or the molecular etiology behind each DCIS lesion or grade. The DCIS lesions can be heterogeneous in morphology, genetics, cellular biology, and clinical behavior, posing challenges to our understanding of the molecular mechanisms by which approximately half of all DCIS lesions progress to an invasive status. New strategies that pinpoint molecular mechanisms are necessary to overcome this gap in understanding, which is a barrier to more targeted therapy. In this review, we will discuss the etiological factors associated with DCIS, as well as the complexity of each nuclear grade lesion. Moreover, we will discuss the possible molecular features that lead to progression of DCIS to IDC. We will highlight current therapeutic management and areas for improvement.

Molecular markers of risk of subsequent invasive breast cancer in women with ductal carcinoma in situ: protocol for a population-based cohort study

INTRODUCTION

Ductal carcinoma in situ (DCIS) of the breast is a non-obligate precursor of invasive breast cancer (IBC). Many DCIS patients are either undertreated or overtreated. The overarching goal of the study described here is to facilitate detection of patients with DCIS at risk of IBC development. Here, we propose to use risk factor data and formalin-fixed paraffin-embedded (FFPE) DCIS tissue from a large, ethnically diverse, population-based cohort of 8175 women with a first diagnosis of DCIS and followed for subsequent IBC to: identify/validate miRNA expression changes in DCIS tissue associated with risk of subsequent IBC; evaluate ipsilateral IBC risk in association with two previously identified marker sets (triple immunopositivity for p16, COX-2, Ki67; Oncotype DX Breast DCIS score); examine the association of risk factor data with IBC risk.

METHODS AND ANALYSIS

We are conducting a series of case-control studies nested within the cohort. Cases are women with DCIS who developed subsequent IBC; controls (2/case) are matched to cases on calendar year of and age at DCIS diagnosis. We project 485 cases/970 controls in the aim focused on risk factors. We estimate obtaining FFPE tissue for 320 cases/640 controls for the aim focused on miRNAs; of these, 173 cases/346 controls will be included in the aim focused on p16, COX-2 and Ki67 immunopositivity, and of the latter, 156 case-control pairs will be included in the aim focused on the Oncotype DX Breast DCIS score®. Multivariate conditional logistic regression will be used for statistical analyses.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Institutional Review Boards of Albert Einstein College of Medicine (IRB 2014-3611), Kaiser Permanente Colorado, Kaiser Permanente Hawaii, Henry Ford Health System, Mayo Clinic, Marshfield Clinic Research Institute and Hackensack Meridian Health, and from Lifespan Research Protection Office. The study results will be presented at meetings and published in peer-reviewed journals.

Higher densities of tumour-infiltrating lymphocytes and CD4+ T cells predict recurrence and progression of ductal carcinoma in situ of the breast

AIMS

Host immunity influences cancer progression and therapeutic response. We investigated the potential of tumour-infiltrating lymphocytes (TILs) around ductal carcinoma in situ (DCIS) in predicting recurrence and progression.

METHODS AND RESULTS

CD4, CD8, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression in DCIS from 198 patients was determined by immunohistochemistry. We correlated disease-free survival (DFS), clinicopathological parameters and biomarker expression with TIL density and CD4/CD8 ratio. High TIL density was associated with high nuclear grade (P < 0.001), DCIS PD-L1 expression (P = 0.008), TIL PD-L1 expression (P < 0.001), oestrogen (ER) negativity (P < 0.001), progesterone (PR) negativity (P < 0.001), human epidermal growth factor receptor 2 (HER2) positivity (P = 0.002) and triple negativity (P = 0.001). TIL PD-L1 expression was associated with triple-negative DCIS (P = 0.028). TIL density was associated with molecular subtypes (P < 0.001). High CD4⁺ T cell density was associated with high nuclear grade (P = 0.001), microinvasion (P = 0.037), ER negativity (P < 0.001), PR negativity (P = 0.001), HER2 positivity (P = 0.004), triple negativity (P = 0.023) and PD-L1 expression in TILs (P < 0.011). High CD4/CD8 ratio was associated with PD-L1 expression in DCIS (P = 0.035) and TILs (P < 0.001). DCIS with higher TIL density disclosed worse DFS (P = 0.012) and was affirmed with multivariate analysis [95% confidence interval (CI) = 1.109-2.554, hazard ratio (HR) = 1.683, P = 0.014]. Poorer DFS for ipsilateral invasive recurrence was found for DCIS with higher CD4⁺ T cell density (P = 0.006) or CD4/CD8 ratio (P = 0.02), confirmed by multivariate analysis for the former (95% CI = 1.369-10.196, HR = 3.736, P = 0.01) and latter (95% CI = 1.311-7.935, HR = 3.225, P = 0.011).

CONCLUSION

DCIS with higher TIL density was associated with poorer prognostic parameters and predicted recurrence, while both CD4⁺ T cell density and CD4/CD8 ratio were associated with both recurrence and ipsilateral invasive recurrence.

LGR5 in breast cancer and ductal carcinoma in situ: a diagnostic and prognostic biomarker and a therapeutic target

BACKGROUND

Novel biomarkers are required to discern between breast tumors that should be targeted for treatment from those that would never become clinically apparent and/or life threatening for patients. Moreover, therapeutics that specifically target breast cancer (BC) cells with tumor-initiating capacity to prevent recurrence are an unmet need. We investigated the clinical importance of LGR5 in BC and ductal carcinoma in situ (DCIS) to explore LGR5 as a biomarker and a therapeutic target.

METHODS

We stained BC (n = 401) and DCIS (n = 119) tissue microarrays with an antibody against LGR5. We examined an LGR5 knockdown ER^- cell line that was orthotopically transplanted and used for in vitro colony assays. We also determined the tumor-initiating role of Lgr5 in lineage-tracing experiments. Lastly, we transplanted ER^- patient-derived xenografts into mice that were subsequently treated with a LGR5 antibody drug conjugate (anti-LGR5-ADC).

RESULTS

LGR5 expression correlated with small tumor size, lower grade, lymph node negativity, and ER-positivity. ER⁺ patients with LGR5^high tumors rarely had recurrence, while high-grade ER^- patients with LGR5^high expression recurred and died due to BC more often. Intriguingly, all the DCIS patients who later died of BC had LGR5-positive tumors. Colony assays and xenograft experiments substantiated a role for LGR5 in ER^- tumor initiation and subsequent growth, which was further validated by lineage-tracing experiments in ER^- /triple-negative BC mouse models. Importantly, by utilizing LGR5^high patient-derived xenografts, we showed that anti-LGR5-ADC should be considered as a therapeutic for high-grade ER^- BC.

CONCLUSION

LGR5 has distinct roles in ER^- vs. ER⁺ BC with potential clinical applicability as a biomarker to identify patients in need of therapy and could serve as a therapeutic target for high-grade ER^- BC.

HER2-Overexpressing Ductal Carcinoma In Situ Associated with Increased Risk of Ipsilateral Invasive Recurrence, Receptor Discordance with Recurrence

The impact of HER2 status in ductal carcinoma in situ (DCIS) on the risk of progression to invasive ductal carcinoma (IDC) has been debated. We aim to use a national database to identify patients with known HER2 status to elucidate the effect of HER2 overexpression on ipsilateral IDC (iIDC) development. We performed survival analysis on patient-level data using the U.S. NCI's Surveillance Epidemiology and End Results program. We identified patients diagnosed with DCIS who underwent lumpectomy and had known HER2 status. Competing risks analysis was performed. A total of 1,540 patients had known HER2 status and met inclusion criteria. Median age at diagnosis was 60, median follow-up time was 44.5 months. A total of 417 (27.1%) patients were HER2 positive and 1,035 (67.2%) were HER2 negative. Twenty-two (1.4%) patients developed iIDC and 27 (1.8%) developed ipsilateral in situ or contralateral disease. The estimated cumulative incidence of iIDC at 5 years was 1.9% for all patients, 1.2% for HER2-negative and borderline patients, and 3.9% for HER2-positive patients. On multivariate competing risks regression, two factors were significant for iIDC: radiation (protective) therapy within 24 months (HR, 0.05; P = 0.00006) and HER2 overexpression (increased likelihood; HR, 2.72; P = 0.044). Patients with HER2-positive DCIS were more likely to have recurrences with receptor discordance. HER2 may serve as a prognostic factor for invasive recurrence and was the only lesion-related factor to significantly relate to iIDC development. It may also be associated with receptor discordance of recurrences. Further large studies will be needed to confirm these results.

Ductal Carcinoma In Situ of the Breast: Perspectives on Tumor Subtype and Treatment

Objective

To evaluate ductal carcinoma in situ (DCIS) characteristics and the effect of different treatment strategies. Patients and Methods. Using data with known hormone receptor (HoR) and human epidermal growth factor receptor 2 (HER2) status obtained by the Surveillance, Epidemiology, and End Results (SEER) program from 2010-2014, the study was conducted to investigate tumor subtype-specific differences in various characteristics, overall survival (OS), and breast cancer-specific mortality (BCSM).

Results

A total of 3415 patients with DCIS were eligible. Compared with HoR+/HER- subgroup, patients with triple-negative (TN) and HoR-/HER+ were commonly higher in grade, larger in size, and tended to receive mastectomy (P < 0.05). The multivariate analysis revealed that patients with TN were more likely to have a poorer OS and show a higher breast cancer-specific mortality compared with the HoR+/HER- subgroup (P < 0.05). Multivariate analysis on the history of local treatment and surgery showed patients receiving breast-conserving surgery (BCS) plus radiotherapy (R) and BCS plus axillary lymph node dissection was likely to improve OS without affecting breast cancer-specific mortality (P < 0.05).

Conclusion

The results demonstrate that DCIS associated with TN subtype portends poor prognosis. Meanwhile, BCS plus R was a preferable option and resulted in survival rates better than those achieved with mastectomy, and SLNB should be considered as an appropriate assessment of axillary staging in patients with DCIS.

The challenge of avoiding over- and under-treatment in older women with ductal cancer in situ: A scoping review of existing knowledge gaps and a meta-analysis of real-world practice patterns

Ductal cancer in situ (DCIS) is mainly a screen-detected disease and although the risk for breast cancer is age-dependent, most screening programs do not include women over the age of 75 years. Older women are usually excluded from clinical trials and treatment practices are largely based on observational studies or extrapolation of trial results from younger patients, leading to either over- or under-treatment of this population. We systematically reviewed available electronic databases for DCIS treatment patterns and outcomes in older patients 15 years. Inclusion criteria allowed for randomised controlled trials, cohort studies, case-control and cross-sectional studies, as well as meta-analyses, systematic reviews and position papers. Results showed that, although elderly are not necessarily frail, they are generally treated as such by physicians, aiming to de-escalate therapeutic interventions. After adjusting for frailty, age seems to be a significant factor for less surgery; however, older women with DCIS are more probable to receive surgery than their counterparts with early invasive cancer. DCIS biology and subtypes are independent risk factors for local recurrence or progression to invasive carcinoma, if DCIS is under-treated. The end-benefit of surgery, radio- and endocrine-therapy depend on additional parameters, such as life expectancy, co-morbidities and competing risks of death. Screen-detected DCIS in older women is a challenging clinical problem, mainly due to the lack of high-level data. Therapeutic strategies should be tailored to life expectancy and performance status, DCIS features and patient preference, aiming at combining optimal oncological outcomes with maintenance of quality of life.

Breast Ductal Carcinoma in Situ: Precursor to Invasive Breast Cancer

This Editorial introduces this month's special Breast Ductal Carcinoma in Situ Theme Issue, a series of reviews intended to highlight the relationship of ductal carcinoma in situ as a precursor to breast cancer and emphasize the need for appropriate treatment in hopes of minimizing the progression to invasive disease.

The clinical value of detecting microcalcifications on a mammogram

Many breast lesions are associated with microcalcifications that are detectable by mammography. In most cases, radiologists are able to distinguish calcifications usually associated with benign diseases from those associated with malignancy. In addition to their value in the early detection of breast carcinoma and accurate radiological diagnosis, the presence of microcalcifications often affects the extent of surgical intervention. Certain types of microcalcifications are associated with negative genetic and molecular characteristics of the tumor and unfavorable prognosis. Microcalcifications localized in the larger ducts (duct-centric, casting-type microcalcifications) represent an independent negative prognostic marker compared to lesions containing other types of microcalcifications and to non-calcified lesions. In this review, we summarize the theoretical and methodological background for understanding the clinical impact and discuss the diagnostic and prognostic value of microcalcifications detected in the breast by mammography.

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.

Long-term Surveillance of Ductal Carcinoma in Situ Detected with Screening Mammography versus US: Factors Associated with Second Breast Cancer

Background The relationship between method of breast cancer screening (mammography or US) and survival outcome in patients with screening-detected ductal carcinoma in situ (DCIS) has not been determined. Purpose To investigate whether different methods of breast cancer screening are associated with different survival outcomes in patients with screening-detected DCIS and to evaluate clinical-pathologic and imaging factors associated with second breast cancer. Materials and Methods We retrospectively identified women who underwent surgery to treat DCIS initially detected with screening mammography or US between July 2004 and December 2011 in a single institution. Overall survival (OS) and disease-free survival (DFS) were assessed. Factors associated with second breast cancer (invasive carcinoma or DCIS) were found with multivariable Cox proportional hazards regression analysis. Subgroups were analyzed according to screening method. Results A total of 814 women (median age, 47 years; age range, 25-81 years) were included; 627 underwent treatment for screening mammography-detected DCIS (mammography-detected group), and 187 underwent treatment for screening US-detected DCIS (US-detected group). During follow-up (median, 7 years; interquartile range, 5-8 years), 26 ipsilateral and 26 contralateral second breast cancers (6.4%, 52 of 814) were found, with 44 in the mammography-detected group and eight in the US-detected group. The overall 5-year OS and DFS rates were 100% and 95.3%, respectively. DFS rates did not differ according to screening method (P = .21, 5-year DFS rates were 94.9% in the mammography-detected group and 96.5% in the US-detected group). In the mammography-detected group, higher nuclear grade (intermediate grade: hazard ratio [HR], 5.7; 95% confidence interval [CI]: 1.3, 24.3; P = 0.02) (high grade: HR, 8.0; 95% CI: 1.9, 34.2; P = .01) and dense breast (HR, 3.5; 95% CI: 1.1, 11.4; P = 0.04) were associated with second breast cancer. In the US-detected group, human epidermal growth factor receptor 2 positivity was associated with second breast cancer (HR, 9.2; 95% CI: 2.2, 38.5; P = .002). Conclusion Disease-free survival of patients who underwent treatment for screening-detected ductal carcinoma in situ (DCIS) did not differ according to screening detection method. In patients with screening mammography-detected DCIS, higher nuclear grade and dense breast were associated with second breast cancer, and in patients with screening US-detected DCIS, human epidermal growth factor 2 positivity was associated with second breast cancer. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Fowler in this issue.

Prolyl-4-hydroxylase Α subunit 2 (P4HA2) expression is a predictor of poor outcome in breast ductal carcinoma in situ (DCIS)

Background

Extracellular matrix (ECM) plays a crucial role in tumour behaviour. Prolyl-4-hydroxlase-A2 (P4HA2) is a key enzyme in ECM remodelling. This study aims to evaluate the prognostic significance of P4HA2 in breast ductal carcinoma in situ (DCIS).

Methods

P4HA2 expression was assessed immunohistochemically in malignant cells and surrounding stroma of a large DCIS cohort comprising 481 pure DCIS and 196 mixed DCIS and invasive carcinomas. Outcome analysis was evaluated using local recurrence free interval (LRFI).

Results

High P4HA2 expression was detected in malignant cells of half of pure DCIS whereas its expression in stroma was seen in 25% of cases. Higher P4HA2 expression was observed in mixed DCIS cases compared to pure DCIS both in tumour cells and in stroma. High P4HA2 was associated with features of high risk DCIS including younger age, higher grade, comedo necrosis, triple negative and HER2-positive phenotypes. Interaction between P4HA2 and radiotherapy was also observed regarding the outcome. High P4HA2 expression was an independent prognostic factor in predicting shorter LRFI.

Conclusion

P4HA2 plays a role in DCIS progression and can potentially be used to predict DCIS outcome. Incorporation of P4HA2 with other clinicopathological parameters could refine DCIS risk stratification that can potentially guide management decisions.

Functional Role of miRNAs in the Progression of Breast Ductal Carcinoma in Situ

miRNAs are small RNAs that influence gene expression by targeting mRNAs. Depending on the function of their target genes, miRNAs may regulate the expression of oncogenes and tumor suppressors, thereby contributing to the promotion or inhibition of tumor progression. Ductal carcinoma in situ (DCIS), although often diagnosed as breast cancer, is a potential precursor to invasive ductal carcinoma. Many of the genetic events required for the invasive progression of DCIS occur at the preinvasive stage, and these events include changes in the expression of miRNAs. Aberrant expression of miRNAs can influence specific oncogenic or tumor-suppressive pathways required for breast cancer progression. miRNAs in DCIS have been shown to influence hormone signaling, cell-cell adhesion, epithelial-to-mesenchymal transition, transforming growth factor β signaling, maintenance of cancer stem cells, and modulation of the extracellular matrix. Additionally, extracellular DCIS miRNAs, such as those found in exosomes, may promote invasive progression by modifying the tumor microenvironment. Here, we review the miRNAs that have been identified in DCIS and how they may contribute to the progression to invasive disease. We also touch on the current state of miRNA therapy development, including the current challenges, and discuss the key future perspectives for research into miRNA function for the purpose of miRNA therapy development for DCIS.

Characterization of Molecular Subtypes of Paget Disease of the Breast Using Immunohistochemistry and In Situ Hybridization

Context.—

Paget disease of the breast, in most cases, represents intraepidermal spread of ductal carcinoma in situ. Molecular subtypes of invasive carcinoma of the breast have prognostic and therapeutic significance and show characteristic distribution. Little is known about the distribution of molecular subtypes in Paget disease of the breast.

Objectives.—

To examine the distribution of molecular subtypes in Paget disease of the breast and to compare them to concurrent invasive carcinoma of the breast, if present.

Design.—

We examined 48 cases of Paget disease of the breast with immunohistochemistry and antibodies against estrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), and Ki-67, as well as HER2 chromogenic in situ hybridization, to classify the cases into molecular subtypes. Then, we compared the results to the molecular subtypes of associated invasive carcinoma of the breast, if present.

Results.—

The HER2 subtype was the most common found in Paget disease of the breast, followed by the luminal B subtype and 2 cases of the triple-negative subtype. The associated invasive carcinoma cases were most often of the luminal B subtype, followed by the HER2 subtype and the triple-negative subtype. The molecular subtype of Paget disease and invasive carcinoma was congruent in most of the cases.

Conclusions.—

Molecular subtypes of invasive carcinoma of the breast can already be detected in Paget disease. The distribution of molecular subtypes of Paget disease and of Paget disease–associated invasive carcinoma differs from invasive carcinoma without associated Paget disease, with the HER2 subtype overrepresented in Paget disease and associated invasive carcinoma and the luminal and triple-negative subtypes underrepresented.

A national multicenter study on 1072 DCIS patients treated with breast-conserving surgery and whole breast radiotherapy (COBCG-01 study)

BACKGROUND AND PURPOSE

Breast-conserving surgery (BCS) and whole breast radiation (RT) with or without endocrine therapy (ET) represent the standard of care for ductal carcinoma in situ (DCIS). The use of adjuvant treatments after surgery is still controversial in this setting. We performed a retrospective multicenter analysis on a series of DCIS patients treated with BCS and adjuvant RT.

MATERIALS AND METHODS

We collected clinical data from nine Italian centers on 1072 women having a diagnosis of DCIS and treated between 1997 and 2012. We reported on the 5- and 10-year local recurrence (LR) rates, overall survival, and breast cancer specific survival (BCSS) employing the Kaplan-Meier method.

RESULTS

At a median follow-up of 8.4 years, 67 LR (6.3%) and 47 deaths (4.4%) were observed. LR rates at 5 and 10 years were 3.4% and 7.6%, respectively. BCSS rates at 5 and 10 years were 99.7% and 99.1%, respectively. At univariate regression analysis, postmenopausal state (p = 0.009), estrogen receptor (ER) (p = 0.0001) and progesterone receptor (p = 0.018) positivity and ET (p = 0.006) were inversely correlated with LR. Final surgical margins (FSM) status <1 mm was significantly correlated with higher LR (p = 0.003). At multivariate regression analysis postmenopausal state (p = 0.03), and ER positive (p = 0.045) maintained the significant favorable feature, while FSM <1 mm (p = 0.024) confirmed its negative impact on LR.

CONCLUSIONS

Our real-life study pointed out the significant favorable prognostic role of postmenopausal state and ER positive status on LR occurrence. FSM <1 mm was significantly correlated to a higher chance to experience LR.

Triple-negative and HER2 positive ductal carcinoma in situ of the breast: characteristics, behavior, and biomarker profile

We compared the characteristics, clinical behavior, and biomarker profile between HER2 positive (HER2+) and triple-negative (TN) ductal carcinoma in situ (DCIS) which are considered more aggressive than other DCIS subtypes. In addition, we explored the impact of these features on its potential of progression to invasive breast carcinomas. Cases of DCIS diagnosed at the Department of Pathology, Singapore General Hospital from 1994 to 2010 were identified. TN and HER2+ DCIS cases formed the study cohort. Immunohistochemistry (IHC) was performed for ER, PR, HER2, CK14, EGFR, and p53. Comparisons of clinicopathological features, IHC results, and clinical outcomes were performed between the two groups. We evaluated 145 HER2+ and 85 TN DCIS cases. HER2 positive DCIS had significantly higher nuclear grade (p < 0.001) and more frequent necrosis (p < 0.001) than TN DCIS. HER2 positive DCIS also harbored significantly higher rates of nuclear p53 immunoreactivity (p = 0.002) than TN DCIS. Younger patients (age < 40) with HER2+ and TN DCIS demonstrated statistically significant worse invasive DFS than older women (p < 0.001). Multivariate cox regression analysis (HR 15.08, 95% CI 12.79-81.45, p = 0.002) also confirmed these findings. In addition, younger patients (age < 40) with HER2+ DCIS experienced significantly poorer prognosis when p53 was also positive (p = 0.033). HER2+ DCIS had more aggressive pathological characteristics compared to TN DCIS; accumulation of mutant p53 could possibly be contributory. Age was an independent predictor of aggressive biological behavior of HER2+ and TN DCIS. We demonstrated that younger patients with p53 positive HER2+ DCIS had significantly adverse clinical outcome.

Microinvasive Carcinoma versus Ductal Carcinoma In Situ: A Comparison of Clinicopathological Features and Clinical Outcomes

PURPOSE

Although microinvasive carcinoma is distinct from ductal carcinoma in situ (DCIS), the clinical significance of microinvasion in DCIS remains elusive. The purpose of this study is to evaluate the clinicopathological features and clinical outcomes of microinvasive carcinoma compared with pure DCIS.

METHODS

We assessed 613 cases of DCIS and microinvasive carcinoma that were consecutively resected from 2003 to 2014 and analyzed clinicopathological variables, expression of standard biomarkers such as the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), p53, and Ki-67, and tumor recurrence.

RESULTS

Among the 613 cases, 136 (22.2%) were classified as microinvasive carcinoma. Microinvasive carcinoma was significantly associated with DCIS with a large extent, high nuclear grade, necrosis, and comedotype architectural pattern. ER and PR expressions were dominantly observed in pure DCIS, whereas positive HER2 status, p53 overexpression, and high Ki-67 proliferation indices were more frequently observed in microinvasive carcinoma. Lymph node metastasis was found in only four cases of microinvasive carcinoma with multifocal microinvasion. In the multivariate analysis, DCIS with a large extent, comedo-type architectural pattern, and negative ER status were found to be independent predictors of microinvasion. During follow-up, 12 patients had ipsilateral breast recurrence, and no differences in recurrence rates were observed between patients with DCIS and those with microinvasive carcinoma. The triple-negative subtype was the only factor that was associated with tumor recurrence.

CONCLUSION

Microinvasive carcinomas are distinct from DCIS in terms of clinicopathological features and biomarker expressions but are similar to DCIS in terms of clinical outcomes. Our results suggest that microinvasive carcinoma can be treated and followed up as pure DCIS.

Breast carcinoma in situ: An observational study of tumor subtype, treatment and outcomes

Background & Aims

To evaluate the clinical presentation, treatment and outcome of patients with breast carcinoma in situ (BCIS) with special emphasis on the role of the tumor subtype and local treatment in these patients.

Methods

Using data obtained by the Surveillance, Epidemiology, and End Results (SEER) program from 2010-2013, a retrospective, population-based cohort study was conducted to investigate tumor subtype-specific differences in various characteristics, overall survival (OS) and breast cancer-specific mortality (BCSM).

Results

In all, 6867 patients with BCIS were eligible during the 2010-2013 study period. Compared with the hormone receptor (HoR)+/HER- subgroup, patients with triple negative (TN) breast cancer were more likely to have tumors that were higher in grade and larger in size; they were also more likely to have tumors with ductal and comedo histology and were less likely to have tumors with cribriform and papillary histology (each P < 0.05). During the follow-up period, patients with TN breast cancer had an OS of 97.0% compared with 98.6 % in the HoR+/HER- subgroup (P < 0.05). Furthermore, the BCSM rate was 1.0% for the TN group compared with 0.1% for the HoR+/HER- subgroup (P < 0.05). Multivariate analysis revealed that patients with TN MBC had a poorer OS and BCSM (P <0.05). Multivariate analysis of OS with respect to the local treatment history showed that patients who received breast-conserving surgery (BCS) combined with radiotherapy (R) were more likely to have an improved OS (P < 0.05). Moreover, the results demonstrated that patients who underwent SLNB were more likely to have a lower BCSM (P < 0.05).

Conclusions

The results demonstrate that BCIS appears to alter the prognosis associated with the TN subtype. Meanwhile, BCS plus R was a preferable option and resulted in survival rates that were better than those achieved with mastectomy; thus, SLNB should be considered as an appropriate assessment of axillary staging in patients with BCIS.

ADC at 3.0 T as a noninvasive biomarker for preoperative prediction of Ki67 expression in invasive ductal carcinoma of breast

PURPOSE

To investigate the role of apparent diffusion coefficient (ADC) as an imaging biomarker for invasive ductal carcinoma (IDC) in the breast.

METHODS

Seventy-one patients undergoing 3.0 Tesla DWI were retrospectively enrolled. Correlations between the ADC values and prognostic factors were evaluated.

RESULTS

Multivariate regression analyses showed that Ki67 expression and molecular subtype were independently associated with the ADC. Discriminant analysis excluded the ADC as a good biomarker for subtype, but the mean ADC significantly distinguished Ki67-positive (low ADC) from Ki67-negative (high ADC) lesions, as observed in the in ROC curves, with a diagnostic sensitivity of 1.00 and a cut-off value of 0.97 × 10^-3 mm²/s.

CONCLUSION

The ADC may be helpful for predicting Ki67 expression in IDC preoperatively.

Breast carcinoma in sclerosing adenosis: a clinicopathological and immunophenotypical analysis on 206 lesions

Aims

To fully elucidate the clinicopathological features of breast carcinoma in sclerosing adenosis (SA-BC).

Methods

Clinical and histological characteristics of 206 SA-BCs from 180 patients were retrospectively evaluated. Immunohistochemical phenotype was examined. The clinicopathological relevance of the topographical pattern of SA-BCs was analysed.

Results

Overall, up to 46 patients (25.6%) had contralateral cancer, either SA associated or not. Of 99 cases who underwent core needle biopsy (CNB), 36 were underestimated as adenosis or atypical ductal hyperplasia at CNB, 5 invasive cases were misinterpreted as in situ carcinomas, whereas 4 ductal carcinoma in situ (DCIS) cases were overdiagnosed as invasive carcinoma. Microscopically, 163 tumours were in situ, including 136 DCIS, 19 lobular carcinomas in situ (LCIS) and 8 mixed DCIS/LCIS; of these carcinomas in situ (CIS), 37 had microinvasion. The DCIS group exhibited low, intermediate and high grades in 53.7%, 34.6% and 11.8% of cases, respectively, mostly with solid (43.4%) or cribriform (41.9%) pattern. Forty out of 43 invasive cases were invasive ductal carcinoma (IDC), mostly DCIS predominant. Immunophenotypically, luminal A phenotype was identified in 55.1%, 63.2% and 45.0% of DCIS, LCIS and IDC cases, respectively. Topographical type A group (carcinoma being entirely confined to SA, n=176) was characterised by smaller size, less invasiveness, lower grade and more frequency of luminal A immunophenotype compared with type B group (≥ 50% but not all of the carcinomatous lesion being located in SA, n=30) (all P<0.05).

Conclusions

CIS, especially non-high-grade DCIS, represents the most common variant of SA-BC, and luminal A is the most predominant immunophenotype. CNB assessment might be challenging in some SA-BCs. The topographical pattern has great clinicopathological relevance. Careful evaluation of the contralateral breast and long-term follow-up for patients with SA-BC is necessary given its high prevalence of bilaterality.

Comparison of mammography, ultrasound, and MRI in size assessment of ductal carcinoma in situ with histopathologic correlation

Background The ability to accurately assess tumor size in ductal carcinoma in situ (DCIS) is an important clinical issue when selecting the appropriate treatment plan. Purpose To compare the accuracy of using mammography, ultrasound (US), and magnetic resonance imaging (MRI) to assess DCIS tumor size based on imaging and histopathological findings. Material and Methods Fifty-six patients with DCIS were included. Mammography, US, and MRI were reviewed, and the accuracy of the measured tumor sizes were compared with the imaging and histopathological parameters. Results If visible, tumor measurements demonstrated high reliability with the pathologically determined size, with the best results obtained using US ( k = 0.851) followed by mammography ( k = 0.815) and MRI ( k = 0.738). Tumor size assessment was significantly more accurate when the lesion was shown as a mass on US ( P = 0.003) or MRI ( P < 0.001) with minimal and mild background parenchymal enhancement ( P = 0.016) on MRI. When mammography was used to assess tumor size, the tumors with positive estrogen receptor status and luminal A subtype demonstrated a significantly more accurate tumor size. Conclusion The combination of US and MRI, in addition to mammography, has an important role in assessing the exact tumor extent of DCIS.

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.

Current Approaches to Diagnosis and Treatment of Ductal Carcinoma In Situ and Future Directions

The presentation and treatment of ductal carcinoma in situ (DCIS) has changed substantially over the years. While previously an incidental pathologic finding in more advanced, palpable tumors, the institution of screening mammography has repositioned this disease entity as one largely diagnosed as a non-palpable lesion, often prior to any invasive disease. As DCIS is a precursor to invasive carcinoma, evolution in the approach to treatment has followed in the footsteps of that for invasive disease, including breast conservation therapy, adjuvant radiation, and use of antihormonal therapy. Survival outcomes for DCIS are very high and more recent literature has investigated tailoring therapeutic approaches to avoid overtreatment. Two important areas of ongoing clinical debate concerning overtreatment include use of preoperative MRI and the role of adjuvant radiation. The heterogeneity of the disease makes it difficult to differentiate lesions that would benefit from more aggressive treatment from those in which overtreatment could be avoided. Clinical characteristics, such as histologic appearance, age at diagnosis, and margin status at tumor excision have been established as moderate predictors of disease recurrence, but none has provided strong enough evidence as to guide consensus decisions on adjuvant therapy. Continuing research seeks to define the genetic and molecular characteristics that can predict disease course and serve as the potential targets for novel therapeutic agents. While several markers have shown promise in differentiating tumor aggressiveness, there is still much to be discovered about the precise mechanisms of disease progression and how this can be applied clinically to optimize treatment.

Impact of hormonal status on outcome of ductal carcinoma in situ treated with breast-conserving surgery plus radiotherapy: Long-term experience from two large-institutional series

BACKGROUND

Ductal carcinoma in situ (DCIS) is a heterogeneous disease, for which the best adjuvant treatment is still uncertain. Many attempts of risk-groups stratification have been made over time, developing prognostic scores to predict risk of local recurrence (LR) on the basis of features such as age, final surgical margins (FSM) status, grade, and tumor size. The aim of our analysis was to evaluate the patterns of recurrence from a two large-institutional retrospective series.

PATIENTS AND METHODS

We collected data on 457 patients treated with BCS and adjuvant RT between 1990 and 2012. Final analysis was performed on 278 patients, due to missing data about hormonal status (HS). Patients were treated at the Radiation Oncology Unit of the University of Florence (n = 195), and S. Maria Annunziata Hospital (n = 83) (Florence, Italy).

RESULTS

At a median follow up time of 10.8 years (range 3-25), we observed 20 LR (7.2%). The 5-year and 10-year LR rates were 4.9% and 10.2%, respectively. At Cox regression univariate analysis, estrogen receptor (ER) positive status (p = 0.001), HS positive (p = 0.003), and FSM <1 mm (p = 0.0001) significantly impacted on LR. At Cox regression multivariate analysis positive ER status maintained a protective role (p = 0.003), and FSM status <1 mm its negative impact (p = 0.0001) on LR rate.

CONCLUSIONS

Our experience confirmed the wide heterogeneity of DCIS. Inadequate FSM and negative ER status negatively influenced LR rates. Tumor biology should be integrated in adjuvant treatment decision-making process.

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.

Extent of ductal carcinoma in situ according to breast cancer subtypes: a population-based cohort study

Ductal carcinoma in situ (DCIS) is a precursor of invasive breast carcinoma (IBC). The DCIS component is often more extensive than the invasive component, which affects local control. The aim of our study was to analyze features of DCIS within different IBC subtypes, which may contribute to the optimization of personalized approaches for patients with IBC. Patients with IBC reported according to the synoptic reporting module in the Netherlands between 2009 and 2015 were included. Data extraction included characteristics of the invasive component and, if present, several features of the DCIS component. Resection margin status analyses were restricted to patients undergoing breast-conserving surgery (BCS). Differences between subtypes were tested by a Chi-square test, spearman’s Rho test or a one-way ANOVA test. Overall, 36.937 cases of IBC were included. About half of the IBCs (n = 16.014; 43.4 %) were associated with DCIS. Her2+ IBC (irrespective of ER status) was associated with a higher prevalence of adjacent DCIS, a larger extent of DCIS and a higher rate of irradicality of the DCIS component as compared to ER+/Her2− and triple-negative subtypes (P < 0.0001 for all variables). The prevalence of DCIS in triple-negative IBC on the other hand was lowest. In this large population-based cohort study, we showed significant differences between the prevalence and extent of DCIS according to IBC subtypes, which is also reflected in the resection margin status in patients treated with BCS. Our data provide important information regarding the optimization of local therapy according to IBC subtypes.

Invasive ductal breast carcinoma with predominant intraductal component: Clinicopathological features and prognosis

PURPOSE

Invasive ductal carcinoma with predominant intraductal component (IDCPIC) represents almost 5% of breast cancers. Nevertheless few data exist concerning their characteristics and prognostic behaviour. Our objective was to describe IDCPIC's clinicopathological and prognostic features and compare them to that of invasive ductal carcinoma without predominant intraductal component (IDC).

METHODS

Retrospective single centre study including all the localized invasive ductal carcinoma listed in our institutional database. Clinical, radiological and pathological criteria were collected as well as disease-free survival (DFS) data.

RESULTS

From 1995 to 2008, 4109 invasive ductal breast cancers treated were included. Out of them 192 (4.7%) were IDCPIC. Most of IDCPIC (63%) were discovered by radiological screening whereas IDC suspicion was more often clinical (82.7% vs 49.5%, p < 0.001). Pathological lymph node involvement was less frequent in IDCPIC (35.8 vs 44.3%, p = 0.04). Invasive tumour median size was 2-fold smaller in IDCPIC (10 mm vs 20 mm, p<0.001). Hormone receptors expression was similar between both groups whereas HER2 overexpression was more frequent in IDCPIC (32% vs 14.3%, p<0.001). Mastectomy was more frequently performed for IDCPIC (67.7% vs 30.3%, p < 0.001) whereas chemotherapy and radiation therapy were less frequent (55.5% vs 68%, and 82.8% vs 95.5%, respectively, p < 0.001 for both). After matching for discriminant clinicopathological features (tumour size, lymph node involvement, vascular invasion, HER2), DFS was similar in both groups (5-year DFS of 87.4% vs 84.4%, p = 0.47).

CONCLUSION

IDCPIC and other IDC with invasive components showing similar clinicopathological features display a similar prognosis.

Value of Breast Cancer Molecular Subtypes and Ki67 Expression for the Prediction of Efficacy and Prognosis of Neoadjuvant Chemotherapy in a Chinese Population

The aim of the study was to determine the predictive role of breast cancer subtypes in the efficacy and prognosis of neoadjuvant chemotherapy (NCT) regimens combining taxanes and anthracyclines.Data from 240 patients with breast cancer who received surgery after 4 to 6 weeks of NCT were retrospectively analyzed. The patients were classified into luminal A, luminal B, HER2 overexpression, and triple negative breast cancer (TNBC) as well as low Ki67 (≤ 14%) and high Ki67 (> 14%) expression groups using immunohistochemistry. NCT outcome parameters were pathological complete response (pCR), clinical complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) 4 weeks after surgery. Long-term outcome parameters were disease-free survival (DFS) with a follow-up time of 3 to 56 months.pCR rates were 1.6%, 13.4%, 22.6%, and 23.8% in patients with luminal A, luminal B, HER2, and TNBC cancers, respectively. High pCR rates correlated with high Ki67 expression (> 40%) (P < 0.001, HR = 0.17, 95% CI: 0.074-0.37) and negative estrogen receptor (ER) status (P < 0.001, HR = 3.74, 95% CI: 1.71-8.12) in a multivariate analysis. However, the DFS rate of luminal A breast cancer was the highest compared to all other groups, but only significantly higher compared to luminal B (P = 0.035, HR = 1.480, 95% CI: 1.060-1.967) patients and correlated with Ki67 expression > 40% (P = 0.005).Luminal A type patients derived the least benefit from neoadjuvant chemotherapy but had better long-term prognoses. ER status and Ki67 expression served as efficacy predictors for NCT, whereas only Ki67 expression > 40% correlated with long-term treatment outcomes.

Cancer statistics: Breast cancer in situ

An estimated 60,290 new cases of breast carcinoma in situ are expected to be diagnosed in 2015, and approximately 1 in 33 women is likely to receive an in situ breast cancer diagnosis in her lifetime. Although in situ breast cancers are relatively common, their clinical significance and optimal treatment are topics of uncertainty and concern for both patients and clinicians. In this article, the American Cancer Society provides information about occurrence and treatment patterns for the 2 major subtypes of in situ breast cancer in the United States-ductal carcinoma in situ and lobular carcinoma in situ-using data from the North American Association of Central Cancer Registries and the 13 oldest Surveillance, Epidemiology, and End Results registries. The authors also present an overview of in situ breast cancer detection, treatment, risk factors, and prevention and discuss research needs and initiatives.

Copy number analysis of ductal carcinoma in situ with and without recurrence

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer and a frequent mammographic finding requiring treatment. Up to 25% of DCIS can recur and half of recurrences are invasive, but there are no reliable biomarkers for recurrence. We hypothesised that copy number aberrations could predict likelihood of recurrence. We analysed a cohort of pure DCIS cases treated only with wide local excision for genome-wide copy number and loss of heterozygosity using Affymetrix OncoScan MIP arrays. Cases included those without recurrence within 7 years (n = 25) and with recurrence between 1 and 5 years after diagnosis (n = 15). Pure DCIS were broadly similar in copy number changes compared with invasive breast cancer, with the consistent exception of a greater frequency of ERBB2 amplification in DCIS. There were no significant differences in age or ER status between the cases with a recurrence vs those without. Overall, the DCIS cases with recurrence had more copy number events than the DCIS without recurrence. The increased copy number appeared non-random with several genomic regions showing an increase in frequency in recurrent cases, including 20 q gain, ERBB2 amplification and 15q loss. Copy number changes may provide prognostic information for DCIS recurrence, but validation in additional cohorts is required.

Characteristics and behaviour of screen-detected ductal carcinoma in situ of the breast: comparison with symptomatic patients

Breast cancer is the most common malignancy in Singapore women. Ductal carcinoma in situ (DCIS) is the putative, non-obligate precursor of the majority of invasive breast cancers. The efficacy of the Singapore breast-screening pilot project in detecting early stage breast cancer led to the launch of a national breast-screening programme, BreastScreen Singapore (BSS), in January 2002. In this study, we compared clinicopathological and immunohistochemical characteristics, as well as clinical outcomes, between screen-detected and symptomatic DCIS. The study cohort comprised 1202 cases of DCIS diagnosed at Singapore General Hospital from 1994 to 2010. Comparison of clinicopathological parameters, immunohistochemical results of ER, PR, HER2, CK14, EGFR, and 34βE12, and clinical outcomes was carried out between the 2 groups. Amongst 1202 cases, 610 (50.7%) were screen-detected and 592 (49.3%) were symptomatic DCIS. Screen-detected cases were smaller in size (P < 0.001), of lower nuclear grade (P = 0.004), and more frequently expressed ER (P < 0.001). Luminal A phenotype was more frequently observed in screen-detected DCIS, while triple-negative and HER2 phenotypes were more common in symptomatic DCIS (P < 0.001). The basal-like phenotype was also more frequent in symptomatic DCIS (P = 0.041). Mean and median follow-up was 99.7 and 97.8 months, respectively, with a maximum follow-up of 246.0 months. More symptomatic patients developed invasive recurrences compared to screen-detected patients (P = 0.001). A trend for better disease-free survival was observed in screen-detected patients (P = 0.076). Patients who were screen-detected experienced better overall survival than those with symptomatic DCIS (P = 0.007). Our data indicate a more favourable outcome of screen-detected DCIS patients confirming the role of BSS in early identification of this curable disease.

The prognostic role of HER2 expression in ductal breast carcinoma in situ (DCIS); a population-based cohort study

Background

HER2 is a well-established prognostic and predictive factor in invasive breast cancer. The role of HER2 in ductal breast carcinoma in situ (DCIS) is debated and recent data have suggested that HER2 is mainly related to in situ recurrences. Our aim was to study HER2 as a prognostic factor in a large population based cohort of DCIS with long-term follow-up.

Methods

All 458 patients diagnosed with a primary DCIS 1986–2004 in two Swedish counties were included. Silver-enhanced in situ hybridisation (SISH) was used for detection of HER2 gene amplification and protein expression was assessed by immunohistochemistry (IHC) in tissue microarrays. HER2 positivity was defined as amplified HER2 gene and/or HER2 3+ by IHC. HER2 status in relation to new ipsilateral events (IBE) and Invasive Breast Cancer Recurrences, local or distant (IBCR) was assessed by Kaplan-Meier survival analyses and Cox proportional hazards regression models.

Results

Primary DCIS was screening-detected in 75.5 % of cases. Breast conserving surgery (BCS) was performed in 78.6 % of whom 44.0 % received postoperative radiotherapy. No patients received adjuvant endocrine- or chemotherapy. The majority of DCIS could be HER2 classified (N = 420 (91.7 %)); 132 HER2 positive (31 %) and 288 HER2 negative (69 %)). HER2 positivity was related to large tumor size (P = 0.002), high grade (P < 0.001) and ER- and PR negativity (P < 0.001 for both). During follow-up (mean 184 months), 106 IBCRs and 105 IBEs were identified among all 458 cases corresponding to 54 in situ and 51 invasive recurrences. Eighteen women died from breast cancer and another 114 had died from other causes. The risk of IBCR was statistically significantly lower subsequent to a HER2 positive DCIS compared to a HER2 negative DCIS, (Log-Rank P = 0.03, (HR) 0.60 (95 % CI 0.38–0.94)). Remarkably, the curves did not separate until after 10 years. In ER-stratified analyses, HER2 positive DCIS was associated with lower risk of IBCR among women with ER negative DCIS (Log-Rank P = 0.003), but not for women with ER positive DCIS.

Conclusions

Improved prognostic tools for DCIS patients are warranted to tailor adjuvant therapy. Here, we demonstrate that HER2 positive disease in the primary DCIS is associated with lower risk of recurrent invasive breast cancer.

Proportion and clinical outcomes of postoperative radiotherapy omission after breast-conserving surgery in women with breast cancer

PURPOSE

The present study was conducted to investigate the proportion and clinical outcomes of breast cancer patients who did not receive postoperative radiotherapy (PORT) after breast-conserving surgery (BCS).

METHODS

This retrospective study included all breast cancer patients received curative BCS without PORT between 2003 and 2013. In the PORT omission group, characteristics and local recurrence differences were compared between the recommended group and the refused group. To compare the local recurrence-free survival (LRFS) of the PORT omission group and the control group who received PORT, subjects were selected by using the pooled data of patients treated between 1994 and 2007.

RESULTS

During the study period, 96 patients did not receive PORT among a total of 6,680 patients who underwent BCS. Therefore, the overall rate of PORT omission was 1.4%. Among the 96 patients, 20 were recommended for PORT omission (recommended group) and 76 refused PORT (refused group). The median follow-up period of all study participants was 19.3 months (range, 0.3-115.1 months). Patients in the recommended group were older (p=0.004), were more likely to be postmenopausal (p=0.013), and had more number of positive prognostic factors compared with the refused group. Overall, 12 cases of disease recurrence, including 11 cases of local recurrence, developed in the PORT-refused group. The LRFS of the PORT-omission group was significantly inferior to that of patients who received PORT after BCS (p<0.001). In the PORT-omission group, significant favorable prognostic factors for LRFS were having histologic grade 1 or 2 disease (p=0.023), having no axillary lymph node metastasis (p=0.039), receiving adjuvant endocrine therapy (p=0.046), and being in the recommended group (p=0.026).

CONCLUSION

The rate of PORT omission in the present study is very low among women who underwent surgery compared to that of other studies worldwide. PORT omission is significantly related to a high local recurrence rate.

Molecular classification of breast cancer

Breast cancer is a complex, multifaceted disease encompassing a great variety of entities that show considerable variation in clinical, morphological and molecular attributes. Traditional classifications including histological assessment and clinical staging are used to guide patient management. In recent years, there has been exponential progress in molecular analysis with profound implications for our understanding of breast cancer biology and, hence, classification. There are now genome-based frameworks for the molecular categorisation of breast cancer including the development of prognostic and predictive signatures that potentially allow individualisation of treatment. Here we review the current state of the molecular classifications of in situ and invasive breast cancer including special subtypes. Future perspectives are also provided.