Ductal carcinoma in situ, complexities and challenges

Magnetic resonance imaging insights from active surveillance of women with ductal carcinoma in situ

New approaches are needed to determine which ductal carcinoma in situ (DCIS) is at high risk for progression to invasive ductal carcinoma (IDC). We retrospectively studied DCIS patients who declined surgery (2002-2019), and received endocrine therapy (ET) and breast MRI. Baseline MRI and changes at 3 months and 6 months were analyzed by recursive partitioning to stratify IDC risk. Sixty-two patients (63 DCIS; 1 bilateral) with a mean follow-up of 8.5 years were included. Fifty-one percent remained on active surveillance (AS) without evidence of IDC, with a mean duration of 7.6 years. A decision tree based on MRI features of lesion distinctness and background parenchymal enhancement (BPE) at baseline and change after 3 months of ET stratified patients into low, intermediate, and high risk for progression to IDC. MRI imaging features in patients treated with ET and undergoing AS, may help determine which DCIS lesions are at low versus high risk for IDC.

Extracellular Microenvironment Alterations in Ductal Carcinoma In Situ and Invasive Breast Cancer Pathologies by Multiplexed Spatial Proteomics

Ductal carcinoma in situ (DCIS) is a heterogeneous breast disease that remains challenging to treat due to its unpredictable progression to invasive breast cancer (IBC). Contemporary literature has become increasingly focused on extracellular matrix (ECM) alterations with breast cancer progression. However, the spatial regulation of the ECM proteome in DCIS has yet to be investigated in relation to IBC. We hypothesized that DCIS and IBC present distinct ECM proteomes that could discriminate between these pathologies. Tissue sections of pure DCIS, mixed DCIS-IBC, or pure IBC (n = 22) with detailed pathological annotations were investigated by multiplexed spatial proteomics. Across tissues, 1,005 ECM peptides were detected in pathologically annotated regions and their surrounding extracellular microenvironments. A comparison of DCIS to IBC pathologies demonstrated 43 significantly altered ECM peptides. Notably, eight fibrillar collagen peptides could distinguish with high specificity and sensitivity between DCIS and IBC. Lesion-targeted proteomic imaging revealed heterogeneity of the ECM proteome surrounding individual DCIS lesions. Multiplexed spatial proteomics reported an invasive cancer field effect, in which DCIS lesions in closer proximity to IBC shared a more similar ECM profile to IBC than distal counterparts. Defining the ECM proteomic microenvironment provides novel molecular insights relating to DCIS and IBC.

Human Ductal Carcinoma In Situ: Advances and Future Perspectives

Due to widespread adoption of screening mammography, there has been a significant increase in new diagnoses of ductal carcinoma in situ (DCIS). However, DCIS outcomes remain unclear. A large fraction of human DCIS (>50%) may not need the multimodality treatment options currently offered to all DCIS patients. More importantly, while we may be overtreating many, we cannot identify those most at risk of invasion or metastasis following a DCIS diagnosis. This review summarizes the studies that have furthered our understanding of DCIS pathology and mechanisms of invasive progression by using advanced technologies including spatial genomics, transcriptomics, and multiplex proteomics. This review also highlights a need for rethinking DCIS with a more focused view on epithelial states and programs and their cross talk with the microenvironment.

Net survival of women diagnosed with breast tumours: a population-based study in Switzerland

AIMS OF THE STUDY

Although the incidence of breast carcinoma in situ has been increasing, the prognosis of breast carcinoma in situ patients has not been extensively investigated. Thus, we aimed to compare the characteristics of invasive breast tumours based on whether or not they were preceded by a breast carcinoma in situ and to estimate the 5-year net survival of patients diagnosed with different breast tumours.

METHODS

Data from women diagnosed with breast tumours between 2003 and 2016 were used in our analyses. Net survival analyses were performed using inverse probability of censoring weights (nonparametric Pohar Perme estimator). Under certain assumptions, differences in survival between the cancer population and the general population can be considered to be attributable to the cancer diagnosis (NS).

RESULTS

Descriptive observation of tumour characteristics indicated that invasive breast tumours following a breast carcinoma in situ were more frequently detected at an earlier stage and had less missing information in tumour-specific variables, compared to invasive breast tumours not preceded by a breast carcinoma in situ. Breast carcinoma in situ patients had a 5-year net survival of 1.02 (95% CI: 1.01-1.03), whereas patients diagnosed with invasive breast cancer without a recorded breast carcinoma in situ had a 5-year net survival of 0.89 (95% CI: 0.88-0.90). Patients diagnosed first with breast carcinoma in situ and then with invasive breast cancer had a 5-year net survival of 0.92 (95% CI: 0.85-1.01).

CONCLUSION

Invasive breast tumours that were preceded by a breast carcinoma in situ were detected more frequently at an earlier stage, compared to those that were not. The estimated 5-year net survival of patients with breast tumours was good.

Heterocycles in Breast Cancer Treatment: The Use of Pyrazole Derivatives

Among the aromatic heterocycle rings, pyrazole -a five-membered ring with two adjacent nitrogen atoms in its structure has been postulated as a potent candidate in the pharmacological context. This moiety is an interesting therapeutic target covering a broad spectrum of biological activities due to its presence in many natural substances. Hence, the potential of the pyrazole derivatives as antitumor agents has been explored in many investigations, showing promising results in some cases. In this sense, breast cancer, which is already the leading cause of cancer mortality in women in some countries, has been the topic selected for this review, which covers a range of different research from the earliest studies published in 2003 to the most recent ones in 2021.

Adherence to cancer prevention recommendations and risk of breast cancer in situ in the United Kingdom Biobank

A health-conscious lifestyle may protect against breast cancer in situ. However, breast cancer in situ is mainly detected by screening, and many studies lack information on screening participation. Thus, we evaluated the association between prediagnostic lifestyle and risk of breast cancer in situ, accounting for screening participation at recruitment. A score reflecting the adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations was constructed, using the recommendations on healthy body weight, physical activity, consumption of plant-based foods, red and processed meat, alcohol and avoidance of sugar. Cox proportional hazards regression models were used to investigate the association between the lifestyle score and breast cancer in situ risk, while accounting for important confounders. The lifestyle score was not significantly associated with breast cancer in situ risk (HR_continuous  = 0.96, 95% CI = 0.91-1.03) in the overall cohort. In participants not reporting dietary changes in the past 5 years, the lifestyle score was inversely associated with breast cancer in situ risk (HR_continuous  = 0.92, 95% CI = 0.85-0.99). In those reporting dietary changes in the past 5 years due to illness or other reasons, the lifestyle score was not associated with breast cancer in situ risk (HR_continuous  = 1.04, 95% CI = 0.94-1.15). Lifestyle was inversely associated with breast cancer in situ risk in women not reporting recent changes in their dietary habits. This inverse association is consistent with inverse associations reported in previous studies. Our findings suggest that breast cancer in situ and invasive breast cancer share a similar risk factor profile.

Association Between Surgery Preference and Receipt in Ductal Carcinoma In Situ After Breast Magnetic Resonance Imaging: An Ancillary Study of the ECOG-ACRIN Cancer Research Group (E4112)

Importance

Guiding treatment decisions for women with ductal carcinoma in situ (DCIS) requires understanding patient preferences and the influence of preoperative magnetic resonance imaging (MRI) and surgeon recommendation.

Objective

To identify factors associated with surgery preference and surgery receipt among a prospective cohort of women with newly diagnosed DCIS.

Design, Setting, and Participants

A prospective cohort study was conducted at 75 participating institutions, including community practices and academic centers, across the US between March 25, 2015, and April 27, 2016. Data were analyzed from August 2 to September 24, 2021. This was an ancillary study of the ECOG-ACRIN Cancer Research Group (E4112). Women with recently diagnosed unilateral DCIS who were eligible for wide local excision and had a diagnostic mammogram within 3 months of study registration were included. Participants who had documented surgery and completed the baseline patient-reported outcome questionnaires were included in this substudy.

Exposures

Women received preoperative MRI and surgeon consultation and then underwent wide local excision or mastectomy. Participants will be followed up for recurrence and overall survival for 10 years from the date of surgery.

Main Outcomes and Measures

Patient-reported outcome questionnaires assessed treatment goals and concerns and surgery preference before MRI and after MRI and surgeon consultation.

Results

Of the 368 participants enrolled 316 (86%) were included in this substudy (median [range] age, 59.5 [34-87] years; 45 women [14%] were Black; 245 [78%] were White; and 26 [8%] were of other race). Pre-MRI, age (odds ratio [OR] per 5-year increment, 0.45; 95% CI, 0.26-0.80; P = .007) and the importance of keeping one's breast (OR, 0.48; 95% CI, 0.31-0.72; P < .001) vs removal of the breast for peace of mind (OR, 1.35; 95% CI, 1.04-1.76; P = .03) were associated with surgery preference for mastectomy. After MRI and surgeon consultation, MRI upstaging (48 of 316 [15%]) was associated with patient preference for mastectomy (OR, 8.09; 95% CI, 2.51-26.06; P < .001). The 2 variables with the highest ORs for initial receipt of mastectomy were MRI upstaging (OR, 12.08; 95% CI, 4.34-33.61; P < .001) and surgeon recommendation (OR, 4.85; 95% CI, 1.99-11.83; P < .001).

Conclusions and Relevance

In this cohort study, change in patient preference for DCIS surgery and surgery received were responsive to MRI results and surgeon recommendation. These data highlight the importance of ensuring adequate information and ongoing communication about the clinical significance of MRI findings and the benefits and risks of available treatment options.

Mouse-INtraDuctal (MIND): an in vivo model for studying the underlying mechanisms of DCIS malignancy

Due to widespread adoption of screening mammography, there has been a significant increase in new diagnoses of ductal carcinoma in situ (DCIS). However, DCIS prognosis remains unclear. To address this gap, we developed an in vivo model, Mouse-INtraDuctal (MIND), in which patient-derived DCIS epithelial cells are injected intraductally and allowed to progress naturally in mice. Similar to human DCIS, the cancer cells formed in situ lesions inside the mouse mammary ducts and mimicked all histologic subtypes including micropapillary, papillary, cribriform, solid, and comedo. Among 37 patient samples injected into 202 xenografts, at median duration of 9 months, 20 samples (54%) injected into 95 xenografts showed in vivo invasive progression, while 17 (46%) samples injected into 107 xenografts remained non-invasive. Among the 20 samples that showed invasive progression, nine samples injected into 54 xenografts exhibited a mixed pattern in which some xenografts showed invasive progression while others remained non-invasive. Among the clinically relevant biomarkers, only elevated progesterone receptor expression in patient DCIS and the extent of in vivo growth in xenografts predicted an invasive outcome. The Tempus XT assay was used on 16 patient DCIS formalin-fixed, paraffin-embedded sections including eight DCISs that showed invasive progression, five DCISs that remained non-invasive, and three DCISs that showed a mixed pattern in the xenografts. Analysis of the frequency of cancer-related pathogenic mutations among the groups showed no significant differences (KW: p > 0.05). There were also no differences in the frequency of high, moderate, or low severity mutations (KW; p > 0.05). These results suggest that genetic changes in the DCIS are not the primary driver for the development of invasive disease. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Type of Recurrence, Cause of Death and Second Neoplasms among 737 Patients with Ductal Carcinoma In Situ of the Breast—15-Year Follow-Up

Simple Summary

A retrospective analysis of 737 consecutive DCIS patients with a 15-year follow-up was carried out. Sixty-six recurrences (42% DCIS, 58% invasive) were reported: 61 in the breast and 5 outside the breast. 79% of local recurrences were true recurrences. The highest number of recurrences was reported in patients after local excision without radiotherapy despite the fact that it was the lowest-risk group. Deaths due to DCIS progression were reported in 0.5% of all patients and in 10.5% of patients with invasive recurrences. The majority of deaths were linked to the age of the patients or other diseases, including other neoplasms.

Abstract

Aim: To assess the outcomes of 737 consecutive patients with DCIS, with particular attention to the type of recurrences, other malignancies and causes of deaths. Material and Methods: A retrospective analysis of 737 consecutive DCIS patients treated in one institution in the years 1996–2011 was carried out. The cumulative recurrence risk, DFS, OS depending on the method of treatment (mastectomy, breast-conserving treatment (BCT), breast-conserving surgery (BCS)) and cause of death were assessed. Results: Sixty-six recurrences (42% DCIS, 58% invasive) were reported: 61 in the breast and 5 outside the breast. The cumulative recurrence risk after a 15-year observation after mastectomy, BCT and BCS was 3.2%, 19.5% and 31.2%, respectively (p < 0.001). The 15-year DFS after mastectomy, BCT and BCS was 72%, 65% and 48%, respectively (p < 0.001). The 15-year OS after mastectomy, BCT and BCS was 75%, 83% and 70%, respectively (p = 0.329). Deaths due to DCIS progression were reported in four (0.5%) of the overall patients and in 10.5% of patients with invasive recurrences. The majority of deaths were linked to the age of the patients or other diseases, including other neoplasms, but not DCIS. Conclusions: The highest number of recurrences was reported in patients after BCS, despite the fact that it was the lowest-risk group. In total, 79% of local recurrences were true recurrences and 58% were invasive recurrences. Local recurrences were effectively treated without an influence on the OS. The percentage of deaths due to DCIS was low and mainly concerned patients with locoregional and distant failure.

National Cancer Institute Experience in Micro-invasive Breast Carcinoma Treatment and Outcome

AbstractBackground: Significant relationship between breast cancer immunophenotype and risk of recurrence either local and/or distant may help determine which patients might benefit more from axillary staging and whether axillary staging is warranted in all cases or not. Patients with microinvasive carcinoma can present with axillary LN. metastasis, with incidence ranges from 0% to 20% . Thus, sentinel node biopsies are considered for patients with microinvasive carcinoma. The role of axillary staging in MIBC is not well defined, with the rate of axillary L.N. metastases ranging 0–11 %. Current studies focus on the clinical characteristics of MIBC. However, only a few studies have evaluated the survival and treatment, especially adjuvant chemotherapy after surgery, for patients with MIBC.Methods: This is a retrospective study of 139 cases diagnosed with microinvasive breast carcinoma from 2011 to 2015 who were identified in the National Cancer Institute, Cairo University. The pathologic database of our hospital was searched to identify patients with a pathologic diagnosis of MIBC on surgical specimens. The clinical features, sonographic and mammographic images and pathology records were reviewed.Results: There is increased incidence of MIBC over the past decade. Patients with MIBC were managed surgically with BCS. MIBC have the good prognosis. However, patients who are negative hormonal receptors have relatively substantial risk of relapse within the first 5 years after surgical operation. Adjuvant chemotherapy can only improve the outcomes of patients with negative hormonal receptors. Further studies with prolonged follow-up of large cohort are warranted to assess the prognostic significance and treatment of this lesion.Keywords: MIBC, CIS, DCIS, BC

Accounting for Preinvasive Conditions in Analysis of Invasive Cancer Risk: Application to Breast Cancer

BACKGROUND

Preinvasive cancer conditions are often actively treated to minimize progression to life-threatening invasive cancers, but this creates challenges for analysis of invasive cancer risk. Conventional methods of treating preinvasive conditions as censoring events or targeting at the composite outcome could both lead to bias.

METHODS

We propose two solutions: one that provides exact estimates of risk based on distributional assumptions about progression, and one that provides risk bounds corresponding to extreme cases of no or complete progression. We compare these approaches through simulations and an analysis of the Sister Study data in the context of ductal carcinoma in situ (DCIS) and invasive breast cancer.

RESULTS

Simulations suggested important biases with conventional approaches, whereas the proposed estimate is consistent when progression parameters are correctly specified, and the risk bounds are robust in all scenarios. With Sister Study, the estimated lifetime risks for invasive breast cancer are 0.220 and 0.269 with DCIS censored or combined. Without detailed progression information, a sensitivity analysis suggested lifetime risk falls between the bounds of 0.214 and 0.269 across assumptions of 10%-95% of DCIS patients progressing to invasive cancer in an average of 1-10 years.

CONCLUSIONS

When estimating invasive cancer risk while preinvasive conditions are actively treated, it is important to consider the implied assumptions and potential biases of conventional approaches. Although still not perfect, we proposed two practical solutions that provide improved understanding of the underlying mechanism of invasive cancer.

Breast intraductal nanoformulations for treating ductal carcinoma in situ II: Dose de-escalation using a slow releasing/slow bioconverting prodrug strategy

Ductal carcinoma in situ (DCIS) represents approximately 20-25% of newly diagnosed breast cancers. DCIS is treated by surgery and possibly radiotherapy. Chemotherapy is only used as adjuvant or neoadjuvant therapy but not as primary therapy. The present study investigated the intraductal administration of Ciclopirox (CPX) formulated in nanosuspensions (NSs) or nanoparticles (NPs) to treat DCIS locally in a Fischer 344 rat model orthotopically implanted with 13762 Mat B III cells. Slow converting esterase responsive CPX prodrugs (CPDs) were successfully synthesized at high purity (> 95%) by directly acetylating the hydroxyl group or by appending a self-immolative linker between CPX and a phenolic ester. Direct esterification CPDs were not sufficiently stable so self-immolative CPDs were formulated in NSs and NPs. Prodrug release was evaluated from poly(lactic-co-glycolic acid) NPs, and CPD4 demonstrated the slowest release rate with the rank order of CPD2 (R = methyl) > CPD3 (R = t-butyl) > CPD4 (R = phenyl). Intraductally administered CPX NS, CPD4 NS, and an innovative mixture of CDP4 NS and NPs (at 1 mg CPX equivalent/duct) demonstrated significant (p < 0.05) in vivo anti-tumor efficacy compared with immediate release (IR) CPX NS and non-treated controls. CPX mammary persistence at 6 h and 48 h after CPD4 NS or NP administration was also greater than after the immediate release CPX NS. A strong correlation between CPX mammary persistence and efficacy is demonstrated. In conclusion, nanoformulations utilizing a slow releasing/slow bioconverting CPX prodrug delivery strategy resulted in significant dose de-escalation (~ five fold) while maintaining anti-tumor efficacy.

Mammary Development and Breast Cancer: a Notch Perspective

Mammary gland development primarily occurs postnatally, and this unique process is complex and regulated by systemic hormones and local growth factors. The mammary gland is also a highly dynamic organ that undergoes profound changes at puberty and during the reproductive cycle. These changes are driven by mammary stem cells (MaSCs). Breast cancer is one of the most common causes of cancer-related death in women. Cancer stem cells (CSCs) play prominent roles in tumor initiation, drug resistance, tumor recurrence, and metastasis. The highly conserved Notch signaling pathway functions as a key regulator of the niche mediating mammary organogenesis and breast neoplasia. In this review, we discuss mechanisms by which Notch contributes to breast carcinoma pathology and suggest potentials for therapeutic targeting of Notch in breast cancer. In summary, we provide a comprehensive overview of Notch functions in regulating MaSCs, mammary development, and breast cancer.

Risk Stratification of Ductal Carcinoma In Situ and Texture Analysis of Contrast-Enhanced Breast Magnetic Resonance Imaging

OBJECTIVE

The aim of this study was to investigate whether texture analysis of contrast-enhanced T1 weighted images could predict risk of ductal carcinoma in situ (DCIS).

METHODS

The study included 185 DCIS lesions that were classified as either low risk or non-low risk using surgical pathology records. All magnetic resonance imaging texture analyses were performed using postprocessing software, and texture-derived parameters were extracted.

RESULTS

The sphericity, compactness, and spherical disproportion were significantly different in the low-risk and non-low risk groups using the Van Nuys Prognostic Index (mean ± SD, 0.479 ± 0.189 vs 0.414 ± 0.176, 0.161 ± 0.159 vs 0.112 ± 0.134, and 2.569 ± 1.434 vs 2.934 ± 1.374, respectively; P < 0.05). In the univariate analyses, sphericity (odds ratio, 7.091; 95% confidence interval, 1.236-40.666; P = 0.028) and compactness (odds ratio, 9.267; 95% confidence interval, 1.125-76.360; P = 0.039) were significantly associated with a high probability of being low risk according to the Van Nuys Prognostic Index.

CONCLUSIONS

Whole-lesion texture analysis may be helpful in identifying patients classified as having low-risk DCIS before surgery.

Axillary staging in ductal carcinoma in situ with microinvasion: A meta-analysis

INTRODUCTION

Ductal carcinoma in situ with microinvasion (DCISM); arguably a more aggressive subtype of DCIS, currently has variable recommendations governing its staging and management in the UK. As a result, there is ongoing controversy surrounding the most appropriate management of DCISM, in particular the need of axillary staging.

METHOD

A search was conducted on the databases MEDLINE and Embase using the keywords: breast, DCISM, microinvasion, "ductal carcinoma in situ with microinvasion", sentinel lymph node biopsy, SLNB, axillary staging was performed. 23 studies were selected for analysis. Primary outcome was the positivity of metastasis of lymph node; secondary outcome looked at characteristics of DCISM that may affect node positivity.

RESULTS

A total of 2959 patients were included. Significant heterogeneity was observed amongst the studies with regards to metastases (I² = 61%; P < 0.01). Lymph node macrometastases was estimated to be 2%. Significant subgroup difference was not observed between SLNB technique and lymph node macrometastases (Q = 0.74; p = 0.69). Statistical significance was observed between the focality of the DCISM and lymph node macrometastases (Q = 8.71; p = 0.033).

CONCLUSION

Although histologically more advanced than DCIS, DCISM is not linked with higher rates of clinically significant metastasis to axillary lymph nodes. Survival rates are very similar to those seen in cases of DCIS. Current evidence suggests that axillary staging in cases of DCISM will not change their overall management, thus may only be an unnecessary and inconvenient additional intervention considering the majority of DCISM diagnoses are made from post-operative pathology samples. A multidisciplinary team approach evaluating pre-operative clinical and histological information to tailor the management specific to individual cases of DCISM would be a preferred approach than routine axillary staging.

Necessity of sentinel lymph node biopsy in ductal carcinoma in situ patients: a retrospective analysis

BACKGROUND

Sentinel lymph node biopsy (SLNB) is unnecessarily performed too often, owing to the high upstaging rates of ductal carcinoma in situ (DCIS). This study aimed to evaluate the upstaging rates of DCIS to invasive cancer, determine the prevalence of axillary lymph node metastasis, and identify the clinicopathological factors associated with upstaging and lymph node metastasis. We also examined surgical patterns among DCIS patients and determined whether SLNB guidelines were followed.

METHODS

We retrospectively analysed 307 consecutive DCIS patients diagnosed by preoperative biopsy in a single centre between 2014 and 2018. Data from clinical records, including imaging studies, axillary and breast surgery types, and pathology results from preoperative and postoperative biopsies, were extracted. Univariate analyses using Chi-square tests and multiple logistic regression analyses were used to analyse the data.

RESULTS

The rate of upstaging to invasive cancer was 19.2% (59/307). DCIS diagnosed by core-needle biopsy (odds ratio [OR]: 6.861, 95% confidence interval [CI]: 2.429-19.379), the presence of ultrasonic mass-forming lesions (OR: 2.782, 95% CI: 1.224-6.320), and progesterone receptor-negative status (OR: 3.156, 95% CI: 1.197-8.323) were found to be associated with upstaging. The rate of sentinel lymph node metastasis was only 1.9% (4/202), and all were total mastectomy patients diagnosed by core-needle biopsy. SLNB was performed in 37.2% of 145 breast-conserving surgery patients and 91.4% of 162 total mastectomy patients. Among the 202 patients who underwent SLNB, 145 (71.7%) without invasive cancer on final pathology had redundant SLNB. Two of 59 patients (3.4%) with disease upstaged to invasive cancer had inadequate primary staging of the axilla, as the rate seemed sufficiently small.

CONCLUSIONS

In patients with a preoperative diagnosis of DCIS, although an unavoidable possibility of upstaging to invasive cancer exists, axillary metastasis is unlikely. Only 2.7% of patients with DCIS undergoing total mastectomy were found to have sentinel lymph node metastases. SLNB should not be performed in breast-conserving surgery patients and should be reserved only for total mastectomy patients diagnosed by core-needle biopsy.

Risk for Invasive Cancers in Women With Breast Cancer In Situ: Results From a Population Not Covered by Organized Mammographic Screening

Background

Even though breast cancer in situ (BCIS) incidence has been increasing, the prognosis of BCIS patients has not been extensively investigated. According to the literature, women with BCIS have a higher risk of developing subsequent invasive breast cancer; conflicting information has been reported regarding their potential risk for a subsequent invasive non-breast cancer.

Methods

Data from 1,082 women, whose first-ever cancer diagnosis was primary BCIS between 2003 and 2015 and were living in the canton of Zurich, were used. Standardized incidence ratios (SIRs) were calculated to compare the risk of an invasive breast or non-breast cancer among women with a primary BCIS with the corresponding risk of the adult female population. SIRs were calculated overall and by patient and tumor characteristics. To investigate potential risk factors (e.g., age at diagnosis, treatment) for a subsequent invasive breast or non-breast cancer we used Cox proportional hazards regression models.

Results

BCIS patients had 6.85 times [95% confidence interval (CI): 5.52-8.41] higher risk of being diagnosed with invasive breast cancer compared to the general population. They additionally faced 1.57 times (95% CI: 1.12-2.12) higher risk of an invasive non-breast cancer. The SIRs were higher for women < 50-years old for both invasive breast and non-breast cancer at BCIS diagnosis. Age ≥ 70-years old at BCIS diagnosis was statistically significantly associated with a subsequent invasive non-breast cancer diagnosis.

Conclusions

BCIS patients had a higher risk of being diagnosed with invasive breast and non-breast cancer compared to the general population. Age 70 years or older at BCIS diagnosis was the only risk factor statistically significantly associated with a subsequent invasive non-breast cancer. Our results support the increased risk for subsequent cancers in BCIS patients reported in the literature. Future studies should establish the risk factors for subsequent cancers, highlight the need for intensive monitoring in this population, and help distinguish BCIS patients who could benefit from systemic therapy to prevent distant cancers.

Unmasking the immune microecology of ductal carcinoma in situ with deep learning

Despite increasing evidence supporting the clinical relevance of tumour infiltrating lymphocytes (TILs) in invasive breast cancer, TIL spatial variability within ductal carcinoma in situ (DCIS) samples and its association with progression are not well understood. To characterise tissue spatial architecture and the microenvironment of DCIS, we designed and validated a new deep learning pipeline, UNMaSk. Following automated detection of individual DCIS ducts using a new method IM-Net, we applied spatial tessellation to create virtual boundaries for each duct. To study local TIL infiltration for each duct, DRDIN was developed for mapping the distribution of TILs. In a dataset comprising grade 2-3 pure DCIS and DCIS adjacent to invasive cancer (adjacent DCIS), we found that pure DCIS cases had more TILs compared to adjacent DCIS. However, the colocalisation of TILs with DCIS ducts was significantly lower in pure DCIS compared to adjacent DCIS, which may suggest a more inflamed tissue ecology local to DCIS ducts in adjacent DCIS cases. Our study demonstrates that technological developments in deep convolutional neural networks and digital pathology can enable an automated morphological and microenvironmental analysis of DCIS, providing a new way to study differential immune ecology for individual ducts and identify new markers of progression.

MicroRNA regulation of cancer stem cells in the pathogenesis of breast cancer

Breast cancer is the most common cancer among women and accounts for 30% of all female malignancies worldwide. Breast cancer stem cells (BCSCs) are a small population of breast cancer cells that exhibit multiple characteristics including differentiation capacity, self-renewal and therapeutic resistance. Recently, BCSCs have attracted attention due to their modulation of breast tumor behaviors and drug resistance. miRNAs are small noncoding mRNAs involved in virtually all biological processes, including stem cell development, maintenance and differentiation. In breast cancer, miRNAs appear to be multi-faceted since they can act as either suppressors or oncogenes to regulate breast cancer progression. This review summarizes the critical roles of miRNAs in regulating multiple signaling pathways such as Wnt/β-catenin, Notch, PI3K/AKT/mTOR, BMI-1 and STAT3 that are important for the BCSC maintenance.

Early diagnosis of breast cancer from exhaled breath by gas chromatography-mass spectrometry (GC/MS) analysis: A prospective cohort study

BACKGROUND

It has proved that there is an association between cancer and volatile organic compounds (VOCs) of exhaled breath. This study targets on verifying the existence of specific VOCs in breathing in breast cancer patients, especially those with ductal carcinoma in situ (DCIS).

METHODS

There were a total of 203 participants included in the final analysis, which included 71 (35.0%) patients with histologically confirmed breast cancer (including 13 with DCIS, 31 with lymph node metastasis-negative status, and 27 with lymph node metastasis-positive status), 78 (38.4%) healthy volunteers, and 54 (26.6%) patients with histologically confirmed gastric cancer. Gas chromatography-mass spectrometry and solid-phase microextraction were used to analyze the breath samples for the presence of VOCs.

RESULTS

There were significant differences in the volatile organic metabolites between the DCIS, lymph node metastasis-negative breast cancer, and lymph node metastasis-positive breast cancer groups compared with the healthy controls as well as between the breast cancer and gastric cancer patients. An overlapping set of seven VOCs, including (S)-1,2-propanediol, cyclopentanone, ethylene carbonate, 3-methoxy-1,2-propanediol, 3-methylpyridine, phenol, and tetramethylsilane, was significantly different between the breast cancer patients and healthy individuals as well as between the breast cancer and gastric cancer patients. The combination of these seven compounds was considered as a biomarker for breast cancer. The sensitivity for predicting DCIS by this set of seven compounds was determined to be 80.77%, and the specificity was determined to be 100%.

CONCLUSIONS

This set of seven breast cancer-specific VOCs can be regarded as one particular expiratory marker for DCIS and will help to establish new screening methods for early breast cancer.

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.

High methionyl-tRNA synthetase expression predicts poor prognosis in patients with breast cancer

Aims

Methionyl–tRNA synthetase (MARS) is known to play a critical role in initiating translation and protection against cellular damages in vivo. The aim of this study was to clarify the role of MARS in breast cancer (BC) progression.

Methods

The expressions of MARS messenger RNA (mRNA) and protein in human BC tissues and adjacent non-cancerous tissues were detected by quantitative real-time PCR, western blot and immunohistochemistry. The prognostic potential of MARS in patients with BC was assessed by univariate and multivariate survival analyses. The association between the MARS expression and BC progression was further evaluated by the bioinformatics database of UALCAN, Gene Expression Profiling Interactive Analysis (GEPIA) and Gene Expression Database of Normal and Tumor Tissues (GENT). The role of MARS in the proliferation, migration and epithelial-to-mesenchymal transition (EMT) of human breast cancer cell line (MCF-7 cells) was investigated after siRNA transfection.

Results

The expression level of MARS mRNA in the fresh BC tissues was significantly higher than that in the adjacent tissues. Immunohistochemistry showed that the expression level of MARS was closely associated with the clinicopathologial parameters of patients with BC, including the HER-2 status, Ki-67 status, molecular classification, tumour grade, N stage and tumour, node, metastasis (TNM) stage, and this finding was further confirmed by UALCAN database. The Kaplan-Meier analysis showed that high MARS expression and TNM stage were predictors of poor prognosis of patients with BC. The proliferation, migration and EMT capabilities of MCF-7 cells were significantly suppressed after MARS knockdown. An overview of UALCAN, GEPIA and GENT results suggested that MARS may be an oncogene of BC, as well as a potential therapeutic target of this malignant tumour.

Conclusions

High expression level of MARS in the human BC tissues was significantly associated with the unfavourable prognosis of patients with BC, suggesting that MARS may serve as a potential prognostic marker for the clinical diagnosis and prognostic prediction of BC.

Intraductal Drug Delivery to the Breast: Effect of Particle Size and Formulation on Breast Duct and Lymph Node Retention

Drug delivery by direct intraductal administration can achieve high local drug concentration in the breast and minimize systemic levels. However, the clinical application of this approach for breast cancer treatment is limited by the rapid clearance of the drug from the ducts. With the goal of developing strategies to prolong drug retention in the breast, this study was focused on understanding the influence of particle size and formulation on breast duct and lymph node retention. Fluorescent-labeled polystyrene (PS) particles ranging in size from 100 to 1000 nm were used to study the influence of particle size. Polylactic acid-co-glycolic acid (PLGA) was used to develop and test formulations for intraductal delivery. Cy 5.5, a near-IR dye, was encapsulated in PLGA microparticles, nanoparticles, and the in situ gel to study the biodistribution in rats using an in vivo imager. PS microparticles (1 μm) showed longer retention in the duct compared to 100 and 500 nm nanoparticles. The ductal retention half-life was 5-fold higher for PS microparticles compared to the nanoparticles. On the other hand, the free dye was cleared from the breast within 6 h. PLGA nanoparticles sustained the release of Cy 5.5 for >4 days. Microparticles and gel showed a much slower release than nanoparticles. PLGA in situ gel and microparticles were retained in the breast for up to 4 days, while the nanoparticles were retained in the breast for 2 days. PLGA nanoparticles and microparticles drained to the axillary lymph node and were retained for up to 24 and 48 h, respectively, while the in situ gel and the free dye did not show any detectable fluorescence in the lymph nodes. Taken together, the results demonstrate the feasibility of prolonged retention in the breast duct and lymph node by optimal formulation design. The findings can serve as a framework to design formulations for localized treatment of breast cancer.

Adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations and risk of in situ breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

BACKGROUND

Even though in situ breast cancer (BCIS) accounts for a large proportion of the breast cancers diagnosed, few studies have investigated potential risk factors for BCIS. Their results suggest that some established risk factors for invasive breast cancer have a similar impact on BCIS risk, but large population-based studies on lifestyle factors and BCIS risk are lacking. Thus, we investigated the association between lifestyle and BCIS risk within the European Prospective Investigation into Cancer and Nutrition cohort.

METHODS

Lifestyle was operationalized by a score reflecting the adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations. The recommendations utilized in these analyses were the ones pertinent to healthy body weight, physical activity, consumption of plant-based foods, energy-dense foods, red and processed meat, and sugary drinks and alcohol, as well as the recommendation on breastfeeding. Cox proportional hazards regression was used to assess the association between lifestyle score and BCIS risk. The results were presented as hazard ratios (HR) and corresponding 95% confidence intervals (CI).

RESULTS

After an overall median follow-up time of 14.9 years, 1277 BCIS cases were diagnosed. Greater adherence to the WCRF/AICR cancer prevention recommendations was not associated with BCIS risk (HR = 0.98, 95% CI 0.93-1.03; per one unit of increase; multivariable model). An inverse association between the lifestyle score and BCIS risk was observed in study centers, where participants were recruited mainly via mammographic screening and attended additional screening throughout follow-up (HR = 0.85, 95% CI 0.73-0.99), but not in the remaining ones (HR = 0.99, 95% CI 0.94-1.05).

CONCLUSIONS

While we did not observe an overall association between lifestyle and BCIS risk, our results indicate that lifestyle is associated with BCIS risk among women recruited via screening programs and with regular screening participation. This suggests that a true inverse association between lifestyle habits and BCIS risk in the overall cohort may have been masked by a lack of information on screening attendance. The potential inverse association between lifestyle and BCIS risk in our analyses is consistent with the inverse associations between lifestyle scores and breast cancer risk reported from previous studies.

Short- and Long-Term Effects of CDK4/6 Inhibition on Early-Stage Breast Cancer

CDK4/6 inhibitors are used in the treatment of advanced estrogen receptor (ER)(+) breast cancer. Their efficacy in ER(-) and early-stage breast cancer is currently under investigation. Here, we show that palbociclib, a CDK4/6 inhibitor, can inhibit both progression of ductal carcinoma in situ (DCIS) and growth of invasive disease in both an ER(-) basal breast cancer model (MCFDCIS) and an ER(+) luminal model (MCF7 intraductal injection). In MCFDCIS cells, palbociclib repressed cell-cycle gene expression, inhibited proliferation, induced senescence, and normalized tumorspheres formed in Matrigel while the formation of acini by normal mammary epithelial cells (MCF10A) was not affected. Palbociclib treatment of mice with MCFDCIS tumors inhibited their malignant progression and reduced proliferation of invasive lesions. Transcriptomic analysis of the tumor and stromal cell compartments showed that cell cycle and senescence genes, and MUC16, an ovarian cancer biomarker gene, were repressed during treatment. Knockdown of MUC16 in MCFDCIS cells inhibited proliferation of invasive lesions but not progression of DCIS. After cessation of palbociclib treatment genes associated with differentiation, for example, P63, inflammation, IFNγ response, and antigen processing and presentation remained suppressed in the tumor and surrounding stroma. We conclude that palbociclib can prevent progression of DCIS and is antiproliferative in ER(-) invasive disease mediated in part via MUC16. Lasting effects of CDK4/6 inhibition after drug withdrawal on differentiation and the immune response could impact the approach to treatment of early-stage ER(-) breast cancer.

Role of Breast MRI in the Evaluation and Detection of DCIS: Opportunities and Challenges

Historically, breast magnetic resonance imaging (MRI) was not considered an effective modality in the evaluation of ductal carcinoma in situ (DCIS). Over the past decade this has changed, with studies demonstrating that MRI is the most sensitive imaging tool for detection of all grades of DCIS. It has been suggested that not only is breast MRI the most sensitive imaging tool for detection but it may also detect the most clinically relevant DCIS lesions. The role and outcomes of MRI in the preoperative setting for patients with DCIS remains controversial; however, several studies have shown benefit in the preoperative evaluation of extent of disease as well as predicting an underlying invasive component. The most common presentation of DCIS on MRI is nonmass enhancement (NME) in a linear or segmental distribution pattern. Maximizing breast MRI spatial resolution is therefore beneficial, given the frequent presentation of DCIS as NME on MRI. Emerging MRI techniques, such as diffusion-weighted imaging (DWI), have shown promising potential to discriminate DCIS from benign and invasive lesions. Future opportunities including advanced imaging visual techniques, radiomics/radiogenomics, and machine learning / artificial intelligence may also be applicable to the detection and treatment of DCIS. Level of Evidence: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;52:697-709.

Proposal for a Histological Staging System of Mammary Carcinomas in Dogs and Cats. Part 2: Feline Mammary Carcinomas

Background: Feline mammary carcinomas (FMCs) are characterized by a high frequency of metastatic spread. The clinical TNM (Tumor, Node, Metastasis) system is used to describe local, regional, and distant tumor extent within the patient, but few publications confirmed its association with survival in cats with FMC. The purpose of this study was to determine if the histological staging system proposed for dogs in part 1 of this article had significant association with prognosis in cats.

Materials and Methods: This retrospective study included 395 female cats with a surgically removed mammary carcinoma, with a 2-year follow-up. Invasiveness (distinction between in situ and invasive FMCs), the pathologic tumor size (pT), lymphovascular invasion (LVI), and the pathologic nodal stage (pN) defined a 5-stage system: Stage 0 (FMCs in situ), Stage I (pT1, LVI–, pN0–pNX), Stage II (pT2, LVI–, pN0–pNX), Stage IIIA (pT1, LVI+ and/or pN+), and Stage IIIB (pT2, LVI+ and/or pN+), where pT1 was ≤20 mm, pT2 was >20 mm, and pNX corresponded to unsampled draining lymph node.

Results: Higher histological stages were associated with reduced disease-free interval, overall survival, and specific survival. For cancer-specific survival, by univariate analysis (p < 0.0001), median survival times and 1-year specific survival rates (1ySSR) were: stage 0 (1484 days; 1ySSR = 85%; N = 55; 14% of the cats), stage I (808 days; 1ySSR = 76%; N = 103; 26%), stage II (377 days; 1ySSR = 51%; N = 56; 14%), stage IIIA (448 days; 1ySSR = 60%; N = 83; 21%), and stage IIIB (207 days; 1ySSR = 29%; N = 98; 25%). The histological stages were also associated with specific survival by multivariate analysis (Hazard Ratio (HR) = 2.72 for stage IIIB, HR = 1.76 for stage IIIA, HR = 1.50 for stage II compared with stage I), independently of Progesterone Receptor expression (HR = 0.34 for PR+ compared with PR– FMCs) and tumor-associated inflammation (HR = 1.33 when moderate to severe compared with absent to mild).

Conclusion: A same histological staging system could be applied in dogs and cats with mammary carcinoma to refine prognosis assessment. In the near future, a preoperative complete tumor clinical staging and treatment based on the published standard of care should be performed in order to better validate the histological staging system here proposed.

Defining the Hallmarks of Metastasis

Metastasis is the primary cause of cancer morbidity and mortality. The process involves a complex interplay between intrinsic tumor cell properties as well as interactions between cancer cells and multiple microenvironments. The outcome is the development of a nearby or distant discontiguous secondary mass. To successfully disseminate, metastatic cells acquire properties in addition to those necessary to become neoplastic. Heterogeneity in mechanisms involved, routes of dissemination, redundancy of molecular pathways that can be utilized, and the ability to piggyback on the actions of surrounding stromal cells makes defining the hallmarks of metastasis extraordinarily challenging. Nonetheless, this review identifies four distinguishing features that are required: motility and invasion, ability to modulate the secondary site or local microenvironments, plasticity, and ability to colonize secondary tissues. By defining these first principles of metastasis, we provide the means for focusing efforts on the aspects of metastasis that will improve patient outcomes.

Frequency of pathogenic germline variants in BRCA1, BRCA2, PALB2, CHEK2 and TP53 in ductal carcinoma in situ diagnosed in women under the age of 50 years

INTRODUCTION

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive ductal breast cancer, and approximately 20% of screen-detected tumours are pure DCIS. Most risk factors for breast cancer have similar associations with DCIS and IDC; however, there is limited data on the prevalence of the known high and moderate penetrance breast cancer predisposition genes in DCIS and which women with DCIS should be referred for genetic screening. The aim of this study was to assess the frequency of germline variants in BRCA2, BRCA1, CHEK2, PALB2 and TP53 in DCIS in women aged less than 50 years of age.

METHODS

After DNA extraction from the peripheral blood, Access Array technology (Fluidigm) was used to amplify all exons of these five known breast cancer predisposition genes using a custom made targeted sequencing panel in 655 cases of pure DCIS presenting in women under the age of 50 years together with 1611 controls.

RESULTS

Case-control analysis revealed an excess of pathogenic variants in BRCA2 (OR = 27.96, 95%CI 6.56-119.26, P = 2.0 × 10^-10) and CHEK2 (OR = 8.04, 95%CI 2.93-22.05, P = 9.0 × 10^-6), with weaker associations with PALB2 (P = 0.003), BRCA1 (P = 0.007) and TP53 (P = 0.02). For oestrogen receptor (ER)-positive DCIS the frequency of pathogenic variants was 9% under the age of 50 (14% with a family history of breast cancer) and 29% under the age of 40 (42% with a family history of breast cancer). For ER-negative DCIS, the frequency was 9% (16% with a family history of breast cancer) and 8% (11% with a family history of breast cancer) under the ages of 50 and 40, respectively.

CONCLUSIONS

This study has shown that breast tumourigenesis in women with pathogenic variants in BRCA2, CHEK2, PALB2, BRCA1 and TP53 can involve a DCIS precursor stage and that the focus of genetic testing in DCIS should be on women under the age of 40 with ER-positive DCIS.

Tumor growth and calcification in evolving microenvironmental geometries

In this paper, we apply the diffuse domain framework developed in Chen and Lowengrub (Tumor growth in complex, evolving microenvironmental geometries: A diffuse domain approach, J. Theor. Biol. 361 (2014) 14-30) to study the effects of a deformable basement membrane (BM) on the growth of a tumor in a confined, ductal geometry, such as ductal carcinoma in situ (DCIS). We use a continuum model of tumor microcalcification and investigate the tumor extent beyond the microcalcification. In order to solve the governing equations efficiently, we develop a stable nonlinear multigrid finite difference method. Two dimensional simulations are performed where the adhesion between tumor cells and the basement membrane is varied. Additional simulations considering the variation of duct radius and membrane stiffness are also conducted. The results demonstrate that enhanced membrane deformability promotes tumor growth and tumor calcification. When the duct radius is small, the cell-BM adhesion is weak or when the membrane is slightly deformed, the mammographic and pathologic tumor extents are linearly correlated, as predicted by Macklin et al. (J. Theor. Biol. 301 (2012) 122-140) using an agent-based model that does not account for the deformability of the basement membrane and the active forces that the membrane imparts on the tumor cells. Interestingly, we predict that when the duct radius is large, there is strong cell-BM adhesion or the membrane is highly deformed, the extents of the mammographic and pathologic tumors are instead quadratically correlated. The simulations can help surgeons to measure DCIS surgical margins while removing less non-cancerous tissue, and can improve targeting of intra- and post-operative radiotherapy.

The mammography screening detection of ductal carcinoma in situ and invasive breast cancer according to women's characteristics: is it the same?

PURPOSE

Detection of ductal carcinoma in situ (DCIS) has increased with the mammography dissemination. Given the potential role of DCIS as a precursor of invasive breast cancer (IBC), we aimed to assess whether women's characteristics have a different effect on the DCIS compared to IBC detection rate.

METHODS

This study included 3,609,569 screening mammograms performed from 2002 to 2015 in our organized breast cancer screening program, which actively invites women 50-69 years of age. The association between women's characteristics and the DCIS detection rate, the IBC detection rate and the odds ratio of DCIS among screen-detected cancers was assessed by logistic regression and generalized estimating equations with independent correlation matrix and sandwich estimator.

RESULTS

A total of 4173 DCIS and 15,136 IBC were screen-detected. Increasing women's age, current hormone replacement therapy use and higher body mass index were less associated with the DCIS than with IBC detection rates (p value for the odds of DCIS among screen-detected cancers of, respectively, < 0.0001, 0.0244 and < 0.0001). In contrast, having a previous breast aspiration or biopsy and increasing breast density were more strongly associated with DCIS than with IBC detection rates (p value of, respectively, 0.0050 and < 0.0001).

CONCLUSION

The results suggest that some women's characteristics could be playing a role in the initiation and other in the progression from in situ to invasive breast cancer. These characteristics can also affect the screening sensitivity, and this effect may differ depending on whether screen-detected cases were DCIS or IBC.

Leveraging the variable natural history of ductal carcinoma in situ (DCIS) to select optimal therapy

PURPOSE

Ductal carcinoma in situ (DCIS) is a non-obligate precursor to invasive ductal carcinoma. The authors sought to discuss the evidence suggesting that not all DCIS will progress to invasive disease if left untreated.

RESULTS

Four lines of evidence align to suggest that not all of this in-situ disease progresses to invasive cancer: its prevalence on screening mammography, studies of missed diagnoses, incidental findings in autopsy specimens, and large retrospective reviews of those treated with excision alone.

CONCLUSION

A clearer understanding of the variable history of DCIS coupled with advances in genomic profiling of the disease holds the promise of reducing widespread over-treatment of this non-invasive cancer. Additionally, identification of higher risk of recurrence subsets may select patients for whom more aggressive treatment may be appropriate.

Intratumoral Heterogeneity in Ductal Carcinoma In Situ: Chaos and Consequence

Ductal carcinoma in situ (DCIS) is a non-invasive proliferative growth in the breast that serves as a non-obligate precursor to invasive ductal carcinoma. The widespread adoption of screening mammography has led to a steep increase in the detection of DCIS, which now comprises approximately 20% of new breast cancer diagnoses in the United States. Interestingly, the intratumoral heterogeneity (ITH) that has been observed in invasive breast cancers may have been established early in tumorigenesis, given the vast and varied ITH that has been detected in DCIS. This review will discuss the intratumoral heterogeneity of DCIS, focusing on the phenotypic and genomic heterogeneity of tumor cells, as well as the compositional heterogeneity of the tumor microenvironment. In addition, we will assess the spatial heterogeneity that is now being appreciated in these lesions, and summarize new approaches to evaluate heterogeneity of tumor and stromal cells in the context of their spatial organization. Importantly, we will discuss how a growing understanding of ITH has led to a more holistic appreciation of the complex biology of DCIS, specifically its evolution and natural history. Finally, we will consider ways in which our knowledge of DCIS ITH might be translated in the future to guide clinical care for DCIS patients.

Modeling Human Ductal Carcinoma In Situ in the Mouse

Breast cancer development is a multi-step process in which genetic and molecular heterogeneity occurs at multiple stages. Ductal carcinoma arises from pre-invasive lesions such as atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS), which progress to invasive and metastatic cancer. The feasibility of obtaining tissue samples from all stages of progression from the same patient is low, and thus molecular studies dissecting the mechanisms that mediate the transition from pre-invasive DCIS to invasive carcinoma have been hampered. In the past 25 years, numerous mouse models have been developed that partly recapitulate the histological and biological properties of early stage lesions. In this review, we discuss in vivo model systems of breast cancer progression from syngeneic mouse models to human xenografts, with particular focus on how accurately these models mimic human disease.

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.

Progression Potential of Ductal Carcinoma in situ Assessed by Genomic Copy Number Profiling

BACKGROUND

Ductal carcinoma in situ (DCIS) of the breast is heterogeneous in terms of the risk of progression to invasive ductal carcinoma (IDC). To treat DCIS appropriately for its progression risk, we classified individual DCIS by its profile of genomic changes into 2 groups and correlated them with clinicopathological progression factors.

METHODS

We used surgically resected, formalin-fixed, paraffin-embedded tissues of 22 DCIS and 30 IDC lesions. We performed immunohistochemical intrinsic subtyping, array-based comparative genomic hybridization, and unsupervised clustering.

RESULTS

The samples were divided into 2 major clusters, A and B. Cluster A showed a greater number of gene and chromosome copy number alterations, a larger IDC/DCIS ratio, a higher frequency of nonluminal subtype, a lower frequency of luminal subtype, and a higher nuclear grade, when compared with cluster B. However, there was no difference in the frequencies of lymph node metastasis between clusters A and B. We identified 9 breast-cancer-related genes, including TP53 and GATA3, that highly contributed to the discrimination of A and B clusters.

CONCLUSION

Classification of breast tumors into rapidly progressive cluster A and the other (cluster B) may contribute to select the treatment appropriate for their progression risk.

Risk factors of sentinel and non-sentinel lymph node metastases in patients with ductal carcinoma in situ of the breast: A nationwide study

OBJECTIVES

Unexplained axillary metastases have been detected in some patients with ductal carcinoma in situ (DCIS), possibly because of occult invasion or iatrogenic tumor cell displacement. The significance of these metastases is unknown and brings into questions the need for upstaging and axillary surgery. What are the risk factors for sentinel lymph node (SN) and non-SN metastases, including the risk of iatrogenic displacement of tumor cells in relation to an excisional biopsy, in patients diagnosed with DCIS?

METHODS

Nationwide data on 1787 women diagnosed with DCIS between 2001 and 2015 were retrieved from the Danish Breast Cancer Group database. The association of clinicopathological variables with a positive SN (isolated tumor cells (ITCs), micro- or macrometastases) was evaluated using univariate and multivariate analyses.

RESULTS

Of the 1787 patients, 71 (4.0%) had a positive SN: 15 (0.8%) had macrometastases, 42 (2.4%) had micrometastases, and 14 (0.8%) had ITCs. Five patients with a positive SN also had a positive non-SN. In adjusted analysis, a positive SN was associated with younger age (P = 0.036), increased size (P = 0.002), palpability (P = 0.0004) and surgical excisional biopsy (P < 0.001).

CONCLUSIONS

The overall risk of a positive SN in patients with DCIS on final pathology is low and less than 9% of these patients had positive non-SNs. This argues against using axillary lymph node dissection in this group. The odds of positive SN after surgical excisional biopsies showed more than a four-fold increase, indicating iatrogenic tumor cell displacement. It is questioned whether these patients should be upstaged and classified as having invasive carcinoma.

Evaluation of intraductal delivery of poly(ethylene glycol)-doxorubicin conjugate nanocarriers for the treatment of ductal carcinoma in situ (DCIS)-like lesions in rats

Ductal carcinoma in situ is the most commonly diagnosed early stage breast cancer. The efficacy of intraductally delivered poly(ethylene glycol)-doxorubicin (PEG-DOX) nanocarriers, composed of one or more DOX conjugated to various PEG polymers, was investigated in an orthotopic ductal carcinoma in situ-like rat model. In vitro cytotoxicity was evaluated against 13762 Mat B III cells using MTT assay. The orthotopic model was developed by inoculating cancer cells into mammary ducts of female Fischer 344 retired breeder rats. The ductal retention and in vivo antitumour efficacy of two of the six nanocarriers (5 kDa PEG-DOX and 40 kDa PEG-(DOX)4) were investigated based on in vitro results. Mammary retention of DOX and PEG-DOX nanocarriers was quantified using in vivo imaging. Histopathologic effects of DOX and PEG-DOX nanocarriers on mammary ductal structure were also investigated. Cytotoxicities of small linear PEG-DOX nanocarriers (5 and 10 kDa) were not different from DOX whereas larger PEG-DOX nanocarriers showed reduced potency. The order of mammary retention was 40 kDa PEG-(DOX)4 > 5 kDa PEG-DOX >> DOX, in normal and tumour-bearing rats. Intraductally administered PEG-DOX nanocarriers and DOX were effective in reducing tumour incidence and increasing survival rate, with no significant differences found among the three treatment groups. However, nanocarriers administered intravenously at the same doses were not effective, and intraductally administered free DOX caused severe local toxicity. Intraductal administration of PEG-DOX nanocarriers is effective and less toxic than that of free DOX, as well as IV DOX/PEG-DOX. Furthermore, PEG-DOX nanocarriers demonstrate the added benefit of prolonging DOX ductal retention, which would necessitate less frequent dosing.

A comprehensive analysis of polymorphic variants in steroid hormone and insulin-like growth factor-1 metabolism and risk of in situ breast cancer: Results from the Breast and Prostate Cancer Cohort Consortium

We assessed the association between 1,414 single nucleotide polymorphisms (SNPs) in genes involved in synthesis and metabolism of steroid hormones and insulin-like growth factor 1, and risk of breast cancer in situ (BCIS), with the aim of determining whether any of these were disease specific. This was carried out using 1,062 BCIS cases and 10,126 controls as well as 6,113 invasive breast cancer cases from the Breast and Prostate Cancer Cohort Consortium (BPC3). Three SNPs showed at least one nominally significant association in homozygous minor versus homozygous major models. ACVR2A-rs2382112 (OR_hom  = 3.05, 95%CI = 1.72-5.44, P_hom  = 1.47 × 10^-4 ), MAST2-rs12124649 (OR_hom  = 1.73, 95% CI =1.18-2.54, P_hom  = 5.24 × 10^-3 ), and INSR-rs10500204 (OR_hom  = 1.96, 95% CI = 1.44-2.67, P_hom =1.68 × 10^-5 ) were associated with increased risk of BCIS; however, only the latter association was significant after correcting for multiple testing. Furthermore, INSR-rs10500204 was more strongly associated with the risk of BCIS than invasive disease in case-only analyses using the homozygous minor versus homozygous major model (OR_hom  = 1.78, 95% CI = 1.30-2.44, P_hom  = 3.23 × 10^-4 ). The SNP INSR-rs10500204 is located in an intron of the INSR gene and is likely to affect binding of the promyelocytic leukemia (PML) protein. The PML gene is known as a tumor suppressor and growth regulator in cancer. However, it is not clear on what pathway the A-allele of rs10500204 could operate to influence the binding of the protein. Hence, functional studies are warranted to investigate this further.

Copy number profiling of oncogenes in ductal carcinoma in situ of the male breast

Characterizing male breast cancer (BC) and unraveling male breast carcinogenesis is challenging because of the rarity of this disease. We investigated copy number status of 22 BC-related genes in 18 cases of pure ductal carcinoma in situ (DCIS) and in 49 cases of invasive carcinoma (IC) with adjacent DCIS (DCIS-AIC) in males using multiplex ligation-dependent probe amplification (MLPA). Results were compared to female BC and correlated with survival. Overall, copy number ratio and aberration frequency including all 22 genes showed no significant difference between the 3 groups. Individual unpaired analysis revealed a significantly higher MTDH copy number ratio in IC compared to DCIS-AIC and pure DCIS (P = 0.009 and P = 0.038, respectively). ADAM9 showed a significantly lower copy number aberration frequency in male BC, compared to female BC (P = 0.020). In DCIS-AIC, MTDH, CPD, CDC6 and TOP2A showed a lower frequency of copy number increase in males compared to females (P < 0.001 for all 4 genes). In IC, CPD gain and CCNE1 gain were independent predictors of poor overall survival. In conclusion, male DCIS and IC showed a similar copy number profile for 21 out of 22 interrogated BC-related genes, illustrating their clonal relation and the genetically advanced state of male DCIS. MTDH showed a higher copy number ratio in IC compared to adjacent and pure DCIS and may therefore play a role in male breast carcinogenesis. Differences were detected between male and female DCIS for 4 genes pointing to differences in breast carcinogenesis between the sexes.

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.

Biologic behavior and long-term outcomes of breast ductal carcinoma in situ with microinvasion

Background

Ductal carcinoma in situ with microinvasion (DCIS-Mi) generally has favorable prognosis, but the long-term outcomes of DCIS-Mi and the biologic evolution from ductal carcinoma in situ (DCIS), DCIS-Mi, to DCIS with T1a breast cancer (DCIS-T1a) has not been specified. The aim of our study was to explore the biological and prognostic features of DCIS-Mi, compared with pure DCIS and DCIS-T1a.

Results

After a median follow-up of 31 months, the 3-year estimated disease free survival(DFS) rate of DCIS-Mi patients was significantly lower than that of pure DCIS patients (89.5% vs 97.1%, P=0.009). Patients with DCIS-Mi or DCIS-T1a tumors had comparable 3-year estimated DFS rates (89.5% vs 94.3%, P=0.13). No significant difference in overall survival (OS) was found among different groups (99.6%, 100% and 99.1% for DCIS, DCIS-Mi and DCIS-T1a, P=0.797). In chemotherapy and trastuzumab-naive DCIS-Mi patients, human epidermal growth factor receptor2 (HER2) positivity (HR=21.8, 95%CI, 1.7-286.8, P=0.019) were independent predictor of worse DFS on multivariate analysis.

Methods

During September 2002 and December 2014, 602 breast cancer patients who underwent radical surgery were retrospectively reviewed. Three hundred and fifty-nine patients (59.6%) had pure DCIS, 84(14.0%) and 159(26.4%) were diagnosed as DCIS-Mi and DCIS-T1a. Clinico-pathological features were compared between different subgroups.

Conclusions

DCIS-Mi displayed a comparable survival to that of DCIS-T1a and a more aggressive biological nature than pure DCIS. Patients with HER2-positive DCIS-Mi had a worse survival and adjuvant chemotherapy plus target therapy needs to be further optimized in those patients.

Characterization of the CD49f+/CD44+/CD24- single-cell derived stem cell population in basal-like DCIS cells

The molecular mechanisms responsible for the Ductal Carcinoma in Situ (DCIS)-Invasive Ductal Carcinoma (IDC) transition have yet to be elucidated. Due to the lack of molecularly targeted therapies, basal-like DCIS has a high risk of recurrence and progression to invasive and metastatic cancers. In this study, by applying a novel single-cell clonogenic approach with the CD49f+/CD44+/CD24- surface markers, we characterized the aggressive clones that have enhanced self-renewal, migratory and invasive capacities derived from a human DCIS model cell line MCF10DCIS. The aggressive clones had elevated ALDH1 activity, lower global DNA methylation and increased expression of stem cell related genes, especially concurrent activation of SOX2/OCT4. In addition, we showed that the aggressive clones have increased expression of lincRNA-RoR and miR-10b compared to non-aggressive clones, which enhance their self-renewal and invasive abilities. Finally, we confirmed our in vitro results in vivo, demonstrating that aggressive clones were capable of forming tumors in nude mice, whereas non-aggressive clones were not. Our data suggest that lincRNA-RoR and miR10b could be used to distinguish aggressive clones from non-aggressive clones within the heterogeneous CD49f+/CD44+/CD24- DCIS population. Our findings also provide the foundation to develop new chemoprevention agents for DCIS-IDC transition.