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

Comparative analysis of clinicopathological characteristics of central necrotizing breast cancer and basal cell-like breast cancer

Purpose

This study aims to compare the clinicopathological and immunohistochemical characteristics of centrally necrotizing carcinoma of the breast (CNC) and basal-like breast cancer (BLBC), as well as to analyze the characteristics of the molecular typing of the CNC.

Methods

The clinicopathological features of 69 cases of CNC and 48 cases of BLBC were observed and compared. EnVision immunohistochemical staining was performed to detect the expressions of hypoxia-inducible factor 1α (HIF-1α), breast cancer susceptibility gene 1 (BRCA1), and vascular endothelial growth factor (VEGF) in CNC and BLBC.

Results

The age of the 69 patients ranged from 32 to 80 years, with an average of 54.55 years. Gross examination showed that most tumors were well-defined single central nodules with a diameter of 1.2~5.0 cm. Microscopically, there is a large necrotic or acellular area in the center of the tumor, mainly composed of tumor coagulative necrosis with varying degrees of fibrosis or hyaline degeneration. A small amount of cancer tissue remained in the form of a ribbon or small nest around the necrotic focus. Among 69 cases of CNC, the proportion of basal cell type (56.5%) was significantly higher than that of lumen type A (18.84%), lumen type B (13.04%), HER2 overexpression (5.8%), and nonexpression (5.8%). A total of 31 cases were followed up for 8~50 months, with an average of 33.94 months. There have been nine cases of disease progression. When compared to BLBC, there were no significant differences in BRCA1 and VEGF protein expression in response to CNC (p > 0.05), but there were significant differences in protein expression in HIF-1α (p < 0.05).

Conclusion

The molecular typing of CNC showed that over half of those were BLBC. No statistically significant difference in the expression of BRCA1 was observed between CNC and BLBC; thus, we predict that targeted therapy for BRCA1 in BLBC may also have considerable effects in CNC patients. The expression of HIF-1α is significantly different in CNC and BLBC, and perhaps HIF-1α can be used as a new entry point to distinguish between the two. There is a significant correlation between the expression of VEGF and HIF-1α in BLBC, and there was no significant correlation between the expression levels of the two proteins in CNC.

Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

The clinical significance of HER2 expression in DCIS

HER2 is an established prognostic and predictive marker for patients with invasive breast cancer. The clinical and biological significance of HER2 overexpression in patients with ductal carcinoma in situ (DCIS) remains poorly defined. DCIS is a heterogeneous disease and some patients with DCIS will not progress to invasive breast cancer. However, clinically significant recurrence rates have been reported after breast-conserving surgery for DCIS and approximately half of these cases will be life-threatening invasive recurrences. Since the incidence of DCIS is rising due to the widespread use of screening mammography, there is robust interest in selecting high-risk DCIS patients that may benefit from adjuvant therapies. Molecular prognostic and predictive models in early invasive breast cancer help clinicians identify patients that will benefit from chemotherapy. Molecular subtyping and profiling could also be useful in treating DCIS patients. According to current practice guidelines, HER2 testing is not recommended in DCIS patients. Nevertheless, evidence suggests that HER2-positive DCIS cases may be associated with adverse clinicopathological parameters and increased recurrence rates. This review summarizes the existing body of evidence linking HER2 expression and ipsilateral breast cancer recurrence in DCIS. HER2, as well as its correlation with other clinicopathological markers might be a useful prognostic and predictive marker, helping clinical decision-making in DCIS patients.

Molecular subtyping reveals uniqueness of prognosis in breast ductal carcinoma in situ patients with lumpectomy

Background

We aimed to analyse the discrepancy in clinical features and prognosis between molecular subtypes in primary ductal carcinoma in situ (DCIS) patients with lumpectomy.

Methods

Primary DCIS patients were identified from the Surveillance, Epidemiology, and End Results registries database from 2010 to 2017. Based on immunohistochemistry markers of hormone receptor (HR) and human epidermal growth factor receptor-2 (HER2), enrolled DCIS cases were divided into four molecular subtypes, HR-HER2-, HR-HER2+, HR + HER2+, and HR + HER2-. Clinical features and prognosis were compared between molecular subtypes. Radiotherapy (RT) effects on prognosis were also analysed in each molecular subtype.

Results

A total of 5,628 DCIS cases were retrospectively enrolled in this study. HR-HER2-, HR-HER2+, HR+HER2+, and HR+HER2- are 299 (5.3%), 498 (8.8%), 1,086 (19.3%), and 3,745 (66.5%), respectively. HR + HER2- cases have smaller tumor size (72.6%, P < 0.001) and lower grade (23.5%, P < 0.001). Comedo necrosis is more frequent in HR-HER2- (24.4%, P < 0.001) and HR-HER2+ DCIS cases (24.3%, P < 0.001). In univariate analyses, HR-HER2+ cases have significantly higher ipsilateral breast event (IBE) recurrence than HR+HER2- cases (P = 0.010). HR-HER2- cases show higher disease-specific mortality than HR+HER2+ cases (P = 0.021). In high-risk DCIS cases, RT reduces the absolute 5-year IBE incidence by 1.3%, 0.7%, 1.9%, and 2.6%, respectively in HR-HER2-, HR-HER2+, HR+HER2+, and HR+HER2- cases, respectively.

Conclusion

In this population-based study, DCIS cases have diverse clinical and prognostic features for different molecular subtypes. Adjusting treatment strategies according to DCIS molecular subtypes is worth advancing.

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HR-HER2+ DCIS shows the highest proportion of high-risk cases. HR + HER2- DCIS shows lowest proportion of high-risk cases.

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HR-HER2+ DCIS shows high risk of IBE recurrence. The DSmortality has no differences among four molecular subtypes.

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RT lowered the probability of IBE incidence in high-risk cases for each molecular subtype of DCIS.

The impact of HER2-directed targeted therapy on HER2-positive DCIS of the breast

Background

In invasive breast cancer, HER2 is a well-established negative prognostic factor. However, its significance on the prognosis of ductal carcinoma in situ (DCIS) of the breast is unclear. As a result, the impact of HER2-directed therapy on HER2-positive DCIS is unknown and is currently the subject of ongoing clinical trials. In this study, we aim to determine the possible impact of HER 2-directed targeted therapy on survival outcomes for HER2-positive DCIS patients.

Materials and methods

The National Cancer Data Base (NCDB) was used to retrieve patients with biopsy-proven DCIS diagnosed from 2004-2015. Patients were divided into two groups based on the adjuvant therapy they received: systemic HER2-directed targeted therapy or no systemic therapy. Statistics included multivariable logistic regression to determine factors predictive of receiving systemic therapy, Kaplan-Meier analysis to evaluate overall survival (OS), and Cox proportional hazards modeling to determine variables associated with OS.

Results

Altogether, 1927 patients met inclusion criteria; 430 (22.3%) received HER2-directed targeted therapy; 1497 (77.7%) did not. Patients who received HER2-directed targeted therapy had a higher 5-year OS compared to patients that did not (97.7% vs. 95.8%, p = 0.043). This survival benefit remained on multivariable analysis. Factors associated with worse OS on multivariable analysis included Charlson-Deyo Comorbidity Score ≥ 2 and no receipt of hormonal therapy.

Conclusion

In this large study evaluating HER2-positive DCIS patients, the receipt of HER2-directed targeted therapy was associated with an improvement in OS. The results of currently ongoing clinical trials are needed to confirm this finding.

Granular necrosis: a distinctive form of cell death in malignant tumours

Foci of necrosis are frequently seen in malignant tumours and may be due to a variety of causes. Different types of necrosis are given various names based upon their morphological features and presumed pathogenesis, such as coagulative, liquefactive and fibrinoid necrosis. Here, we propose the term 'granular necrosis' (GN) for a specific form of tumour necrosis characterised by the presence of well-defined necrotic foci being sharply demarcated from adjacent viable tumour. A constant feature is loss of architecture resulting in an amorphous necrotic mass containing granular nuclear and cytoplasmic debris, without an associated neutrophilic infiltrate. There is usually extensive karyorrhexis, which in larger tumours is more prominent at the periphery. These foci are often microscopic but may range up to several millimetres or larger in size. This distinctive form of necrosis has been erroneously given a variety of names in the literature including coagulative necrosis and microscopic necrosis, which on the basis of the aforementioned gross and microscopic findings is inappropriate. It is apparent that this is a specific form of necrosis, hence the descriptive term 'granular necrosis' that differentiates this form of necrosis from other types. The presence of GN is recognised as occurring in a variety of tumour types, being commonly seen in renal cell carcinoma, where it has been shown to have independent prognostic significance. In some epithelial and stromal tumours of the uterus, the presence of GN also has prognostic significance and is a defining feature for the differentiation of uterine leiomyoma and leiomyosarcoma. The pathogenesis of GN is unresolved. It does not show the features of apoptosis and in recent studies has been shown to have some of the molecular changes associated with necroptosis.

Towards the early detection of ductal carcinoma (a common type of breast cancer) using biomarkers linked to the PPAR(γ) signaling pathway

Breast cancer is a leading cause of morbidity and mortality among women comprising about 12% females worldwide. The underlying alteration in the gene expression, molecular mechanism and metabolic pathways responsible for incidence and progression of breast tumorigenesis are yet not completely understood. In the present study, potential biomarker genes involved in the early progression for early diagnosis of breast cancer has been detailed. Regulation and Gene profiling of Ductal Carcinoma In-situ (DCIS), Invasive Ductal Carcinoma (IDC) and healthy samples have been analyzed to follow their expression pattern employing normalization, statistical calculation, DEGs annotation and Protein-Protein Interaction (PPI) network. We have performed a comparative study on differentially expressed genes among Healthy vs DCIS, Healthy vsIDC and DCIS vs IDC. We found MCM102 and SLC12A8as consistently over-expressed and LEP, SORBS1, SFRP1, PLIN1, FABP4, RBP4, CD300LG, ID4, CRYAB, ECRG4, G0S2, FMO2, ADAMTS5, CAV1, CAV2, ABCA8, MAMDC2, IGFBP6, CLDN11, TGFBR3as under-expressed genes in all the 3 conditions categorized for pre-invasive and invasive ductal breast carcinoma. These genes were further studied for the active pathways where PPAR(γ) signaling pathway was found to be significantly involved. The gene expression profile database can be a potential tool in the early diagnosis of breast cancer.