Heterogeneity of triple-negative breast cancer: histologic subtyping to inform the outcome

Prognostic impact of histological subtyping in triple-negative breast cancer

The impact of special histological types (ST) in triple-negative breast cancer (TNBC) and its association with overall outcome has gained increasing relevance as survival has been linked to specific histological TNBC subtypes. We evaluated the clinicopathological and survival data of 598 patients with 613 TNBCs, including 464 TNBCs of no special type (NST) and 149 TNBCs ST (low-grade, n = 12, 8.1%; high-grade, n = 112, 75.2%; apocrine and androgen receptor-positive [APO AR], n = 25, 16.8%). Patients with low-grade TNBC ST and TNBC ST APO AR were significantly older (P < 0.001) and had a lower Ki67 index (P < 0.001) than those with TNBC NST. Patients with high-grade TNBC ST were significantly older (P = 0.006) and had poorer pathological responses to neoadjuvant chemotherapy (NAC) (P < 0.001) than those with TNBC NST. Significant survival differences were observed between low-grade TNBC ST, TNBC ST APO AR, high-grade TNBC ST, and TNBC NST in the entire study group (DFS, P = 0.002; DDFS, P = 0.001) and in the non-NAC subgroup (OS, P = 0.034; DFS, P = 0.001; DDFS, P < 0.001). Patients with low-grade TNBC ST had the best survival outcomes. Patients with high-grade TNBC ST showed significantly worse outcomes than those with TNBC NST (entire study group: OS, P = 0.049; DFS, P < 0.001; DDFS, P = 0.001; non-NAC subgroup: OS, P = 0.014; DFS, P < 0.001; DDFS, P < 0.001). We conclude that prognostic stratification of TNBC ST is ultimately important for optimizing the therapeutic management of patients with these rare tumor entities.

New insights into acinic cell carcinoma of the breast: clinicopathology, origin of histology, molecular features, prognosis, and treatment

Acinic cell carcinoma (AciCC) of the breast is a rare malignant epithelial neoplasm, with approximately 60 cases reported in the literature. It predominantly affects women and exhibits significant histological heterogeneity. The diagnosis of breast AciCC is primarily based on the presence of eosinophilic and/or basophilic granular cytoplasm and markers of serous acinar differentiation. Despite being considered a low-grade variant of conventional triple-negative breast cancer (TNBC), over 25% of patients with breast AciCC have adverse clinical outcomes. Additionally, in early research, microglandular adenosis (MGA) and atypical MGA were considered potential precursors for various breast cancers, including intraductal carcinoma, invasive ductal carcinoma, adenoid cystic carcinoma, metaplastic carcinoma, and AciCC. Similarly, some studies have proposed that breast AciCC should be considered a type of carcinoma developing in MGA with acinic cell differentiation rather than a distinct entity. Therefore, the pathogenesis of breast AciCC has not yet been clarified. Moreover, to the best of our knowledge, the literature has not summarized the latest prognosis and treatment of breast AciCC. In this review, we synthesized the current literature and the latest developments, aiming at exploring the clinicopathology, histological origin, molecular features, prognosis, and treatment of breast AciCC from a novel perspective.

Triple-negative breast cancer survival prediction: population-based research using the SEER database and an external validation cohort

Introduction

Triple-negative breast cancer (TNBC) is linked to a poorer outlook, heightened aggressiveness relative to other breast cancer variants, and limited treatment choices. The absence of conventional treatment methods makes TNBC patients susceptible to metastasis. The objective of this research was to assess the clinical and pathological traits of TNBC patients, predict the influence of risk elements on their outlook, and create a prediction model to assist doctors in treating TNBC patients and enhancing their prognosis.

Methods

We included 23,394 individuals with complete baseline clinical data and survival information who were diagnosed with primary TNBC between 2010 and 2015 based on the SEER database. External validation utilised a group from The Affiliated Lihuili Hospital of Ningbo University. Independent risk factors linked to TNBC prognosis were identified through univariate, multivariate, and least absolute shrinkage and selection operator regression methods. These characteristics were chosen as parameters to develop 3- and 5-year overall survival (OS) and breast cancer-specific survival (BCSS) nomogram models. Model accuracy was assessed using calibration curves, consistency indices (C-indices), receiver operating characteristic curves (ROCs), and decision curve analyses (DCAs). Finally, TNBC patients were divided into groups of high, medium, and low risk, employing the nomogram model for conducting a Kaplan-Meier survival analysis.

Results

In the training cohort, variables such as age at diagnosis, marital status, grade, T stage, N stage, M stage, surgery, radiation, and chemotherapy were linked to OS and BCSS. For the nomogram, the C-indices stood at 0.762, 0.747, and 0.764 in forecasting OS across the training, internal validation, and external validation groups, respectively. Additionally, the C-index values for the training, internal validation, and external validation groups in BCSS prediction stood at 0.793, 0.755, and 0.811, in that order. The findings revealed that the calibration of our nomogram model was successful, and the time-variant ROC curves highlighted its effectiveness in clinical settings. Ultimately, the clinical DCA showcased the prospective clinical advantages of the suggested model. Furthermore, the online version was simple to use, and nomogram classification may enhance the differentiation of TNBC prognosis and distinguish risk groups more accurately.

Conclusion

These nomograms are precise tools for assessing risk in patients with TNBC and forecasting survival. They can help doctors identify prognostic markers and create more effective treatment plans for patients with TNBC, providing more accurate assessments of their 3- and 5-year OS and BCSS.

Overall Survival and Prognostic Factors in Metastatic Triple-Negative Breast Cancer: A National Cancer Database Analysis

BACKGROUND

Metastatic triple-negative breast cancer (TNBC) is aggressive with poor median overall survival (OS) ranging from 8 to 13 months. There exists considerable heterogeneity in survival at the individual patient level. To better understand the survival heterogeneity and improve risk stratification, our study aims to identify the factors influencing survival, utilizing a large patient sample from the National Cancer Database (NCDB).

METHODS

Women diagnosed with metastatic TNBC from 2010 to 2020 in the NCDB were included. Demographic, clinicopathological, and treatment data and overall survival (OS) outcomes were collected. Kaplan-Meier curves were used to estimate OS. The log-rank test was used to identify OS differences between groups for each variable in the univariate analysis. For the multivariate analysis, the Cox proportional hazard model with backward elimination was used to identify factors affecting OS. Adjusted hazard ratios and 95% confidence intervals are presented.

RESULTS

In this sample, 2273 women had a median overall survival of 13.6 months. Factors associated with statistically significantly worse OS included older age, higher comorbidity scores, specific histologies, higher number of metastatic sites, presence of liver or other site metastases in those with only one metastatic site (excluding brain metastases), presence of cranial and extra-cranial metastases, lack of chemotherapy, lack of immunotherapy, lack of surgery to distant sites, lack of radiation to distant sites, and receipt of palliative treatment to alleviate symptoms. In the multivariate analysis, comorbidity score, histology, number of metastatic sites, immunotherapy, and chemotherapy had a statistically significant effect on OS.

CONCLUSIONS

Through NCDB analysis, we have identified prognostic factors for metastatic TNBC. These findings will help individualize prognostication at diagnosis, optimize treatment strategies, and facilitate patient stratification in future clinical trials.

Triple-negative Breast Carcinoma With Apocrine and Histiocytoid Features: A Clinicopathologic and Molecular Study of 18 Cases

Triple-negative breast cancer (TNBC) is a heterogenous group of tumors. Most TNBCs are high-grade aggressive tumors, but a minority of TNBCs are not high grade, with relatively indolent behavior and specific morphologic and molecular features. We performed a clinicopathologic and molecular assessment of 18 non-high-grade TNBCs with apocrine and/or histiocytoid features. All were grade I or II with low Ki-67 (≤20%). Thirteen (72%) showed apocrine features, and 5 (28%) showed histiocytoid and lobular features. In all, 17/18 expressed the androgen receptor, and 13/13 expressed gross cystic disease fluid protein 15. Four (22.2%) patients were treated with neoadjuvant chemotherapy, but none achieved a pathologic complete response. In all, 2/18 patients (11%) had lymph node metastasis at the time of surgery. None of the cases had a recurrence or disease-specific death, with an average follow-up time of 38 months. Thirteen cases were profiled by targeted capture-based next-generation DNA sequencing. Genomic alterations (GAs) were most significant for PI3K-PKB/Akt pathway (69%) genes, including PIK3R1 (23%), PIK3CA (38%), and PTEN (23%), and RTK-RAS pathway (62%) including FGFR4 (46%) and ERBB2 (15%). TP53 GA was seen in only 31% of patients. Our findings support those on high-grade TNBCs with apocrine and/or histiocytoid features as a clinicopathologic and genetically distinct subgroup of TNBC. They can be defined by features including tubule formation, rare mitosis, low Ki-67 (≤20%), triple-negative status, expression of androgen receptor and/or gross cystic disease fluid protein 15, and GA in the PI3K-PKB/Akt and/or RTK-RAS pathway. These tumors are not sensitive to chemotherapy but have favorable clinical behavior. Tumor subtype definitions are the first step to implementing future trial designs to select these patients.

Unusual presentation of breast adenoid cystic carcinoma resembling adenomyoepithelioma with multiple distinct foci

We describe an unusual case of multifocal breast adenoid cystic carcinoma (AdCC) with adenomyoepitheliomatous morphology. Most breast AdCCs are unifocal and only four cases of multifocal AdCC have been reported previously, however, to our best knowledge, multifocality in AdCC confirmed by molecular analysis has not been reported, so this report adds to the literature on this unique presentation. An 80-year-old woman presented with a left breast mass at 1 o'clock and non-mass enhancement lesion at 5 o'clock on imaging. Incisional biopsy at 1 o'clock showed AdCC based on histopathological features and MYB rearrangement by fluorescent in situ hybridization (FISH). As AdCC involved the margins and the non-mass enhancing lesion remained, mastectomy was performed. Microscopically, the lesion at 5 o'clock demonstrated multinodularity and a biphasic epithelial-basaloid/myoepithelial pattern. Although histological features resembled adenomyoepithelioma, MYB rearrangement was identified on FISH, so the 5 o'clock lesion was also diagnosed as AdCC showing an adenomyoepitheliomatous pattern. This unusual presentation is a potential diagnostic pitfall, so pathologists should consider AdCC as a possible differential diagnosis of multifocal basaloid breast tumors with adenomyoepitheliomatous features.

Regulatory miRNAs, circRNAs and lncRNAs in cell cycle progression of breast cancer

Breast cancer is a complex and heterogeneous disease that poses a significant public health concern worldwide, and it remains a major challenge despite advances in treatment options. One of the main properties of cancer cells is the increased proliferative activity that has lost regulation. Dysregulation of various positive and negative modulators in the cell cycle has been identified as one of the driving factors of breast cancer. In recent years, non-coding RNAs have garnered much attention in the regulation of cell cycle progression, with microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs) being of particular interest. MiRNAs are a class of highly conserved and regulatory small non-coding RNAs that play a crucial role in the modulation of various cellular and biological processes, including cell cycle regulation. CircRNAs are a novel form of non-coding RNAs that are highly stable and capable of modulating gene expression at posttranscriptional and transcriptional levels. LncRNAs have also attracted considerable attention because of their prominent roles in tumor development, including cell cycle progression. Emerging evidence suggests that miRNAs, circRNAs and lncRNAs play important roles in the regulation of cell cycle progression in breast cancer. Herein, we summarized the latest related literatures in breast cancer that emphasize the regulatory roles of miRNAs, circRNAs and lncRNAs in cell cycle progress of breast cancer. Further understanding of the precise roles and mechanisms of non-coding RNAs in breast cancer cell cycle regulation could lead to the development of new diagnostic and therapeutic strategies for breast cancer.

Clinical outcomes and prognostic factors in triple-negative invasive lobular carcinoma of the breast

PURPOSE

Triple-negative invasive lobular carcinoma (TN-ILC) of breast cancer is a rare disease and the clinical outcomes and prognostic factors are not well-defined.

METHODS

Women with stage I-III TN-ILC or triple-negative invasive ductal carcinoma (TN-IDC) of the breast undergoing mastectomy or breast-conserving surgery between 2010 and 2018 in the National Cancer Database were included. Kaplan-Meier curves and multivariate Cox proportional hazard regression were used to compare overall survival (OS) and evaluate prognostic factors. Multivariate logistic regression was performed to analyze the factors associated with pathological response to neoadjuvant chemotherapy.

RESULTS

The median age at diagnosis for women with TN-ILC was 67 years compared to 58 years in TN-IDC (p < 0.001). There was no significant difference in the OS between TN-ILC and TN-IDC in multivariate analysis (HR 0.96, p = 0.44). Black race and higher TNM stage were associated with worse OS, whereas receipt of chemotherapy or radiation was associated with better OS in TN-ILC. Among women with TN-ILC receiving neoadjuvant chemotherapy, the 5-year OS was 77.3% in women with a complete pathological response (pCR) compared to 39.8% in women without any response. The odds of achieving pCR following neoadjuvant chemotherapy were significantly lower in women with TN-ILC compared to TN-IDC (OR 0.53, p < 0.001).

CONCLUSION

Women with TN-ILC are older at diagnosis but have similar OS compared to TN-IDC after adjusting for tumor and demographic characteristics. Administration of chemotherapy was associated with improved OS in TN-ILC, but women with TN-ILC were less likely to achieve complete response to neoadjuvant therapy compared to TN-IDC.

Rare subtypes of triple negative breast cancer: Current understanding and future directions

Rare subtypes of triple-negative breast cancers (TNBC) are a heterogenous group of tumors, comprising 5-10% of all TNBCs. Despite accounting for an absolute number of cases in aggregate approaching that of other less common, but well studied solid tumors, rare subtypes of triple-negative disease remain understudied. Low prevalence, diagnostic challenges and overlapping diagnoses have hindered consistent categorization of these breast cancers. Here we review epidemiology, histology and clinical and molecular characteristics of metaplastic, triple-negative lobular, apocrine, adenoid cystic, secretory and high-grade neuroendocrine TNBCs. Medullary pattern invasive ductal carcinoma no special type, which until recently was a considered a distinct subtype, is also discussed. With this background, we review how applying biological principals often applied to study TNBC no special type could improve our understanding of rare TNBCs. These could include the utilization of targeted molecular approaches or disease agnostic tools such as tumor mutational burden or germline mutation-directed treatments. Burgeoning data also suggest that pathologic response to neoadjuvant therapy and circulating tumor DNA have value in understanding rare subtypes of TNBC. Finally, we discuss a framework for advancing disease-specific knowledge in this space. While the conduct of randomized trials in rare TNBC subtypes has been challenging, re-envisioning trial design and technologic tools may offer new opportunities. These include embedding rare TNBC subtypes in umbrella studies of rare tumors, retrospective review of contemporary trials, prospective identification of patients with rare TNBC subtypes entering on clinical trials and querying big data for outcomes of patients with rare breast tumors.

Norepinephrine/β2-Adrenergic Receptor Pathway Promotes the Cell Proliferation and Nerve Growth Factor Production in Triple-Negative Breast Cancer

PURPOSE

Invasive ductal carcinoma (IDC) accounts for 90% of triple-negative breast cancer (TNBC). IDC is mainly derived from the breast ductal epithelium which is innervated by the 4th to 6th thoracic sympathetic nerves. However, little is known about the contribution of the interactions between sympathetic nerves and breast cancer cells to the malignant progression of TNBC.

METHODS

The expression levels of the β₂-adrenergic receptor (β₂-AR, encoded by ADRB2 gene), nerve growth factor (NGF), and tropomyosin receptor kinase A (TrkA) were determined using immunohistochemistry (IHC). NGF expression levels in the serum were compared by enzyme-linked immunosorbent assay (ELISA). Cell proliferation was assessed using the Cell Counting Kit-8 assay. The β₂-AR, NGF, p-ERK, and p-CERB expression levels were determined using western blotting. TNBC cells and neuronal cells of the dorsal root ganglion (DRG) in 2-day-old Sprague Dawley rats were co-cultured. Using norepinephrine (NE), NGF, and β₂-AR, NGF/TrkA blocker pretreatments, the axon growth of each group of DRG neuron cells was detected by immunofluorescence analysis.

RESULTS

The sympathetic adrenergic neurotransmitter NE activated the ERK signaling pathway in TNBC cells. NE/β₂-AR signaling promotes NGF secretion. NGF further facilitates the malignant progression of TNBC by increasing sympathetic neurogenesis. In the co-culture assay, the sympathetic adrenergic NE/β₂-AR signal pathway also enhanced NGF secretion. NGF binds TrkA in DRG neurons and promotes axonal growth.

CONCLUSION

These results suggest that NE/β₂-AR pathway promotes cell proliferation and NGF production in triple-negative breast cancer.

Anticipating changes in the HER2 status of breast tumours with disease progression-towards better treatment decisions in the new era of HER2-low breast cancers

BACKGROUND

HER2 expression is often negative or low in primary breast cancers (BCs) but its changes with disease progression remain poorly known. We aimed to estimate them between primary and recurrent tumours, and identify predictive factors.

METHODS

We compared the HER2 status, and clinical and pathological characteristics by its evolution category (stable or changed), between all primary BCs and matched recurrences registered in our database in 2000-2020 (n = 512).

RESULTS

HER2-low tumours were the most prevalent at diagnosis (44.9%), followed by HER2-negative tumours (39.3%). HER2 status significantly changed in 37.3% of recurrences, mainly of HER2-negative and HER2-low tumours. HER2-negative tumours which relapsed as HER2-low significantly more frequently expressed oestrogen receptors (ER) and recurred later than stably HER2-negative tumours. Changed HER2 status in distant metastases correlated with lower proliferation rates and higher ER expression in primary tumours, and among metastases of hormone receptor-positive (HR+) tumours-with weak progesterone receptor (PR) expression in primary tumours.

CONCLUSIONS

HER2 status changes with BC progression, with enrichment of HER2-low tumours in advanced stages. The ER+/PR- status, low proliferation index and time to late recurrence correlated with these changes. These findings highlight the need of retesting recurrences, especially of HR + primary tumours, to identify candidates for new anti-HER2 therapies.

Paclitaxel-loaded tumor cell-derived microparticles improve radiotherapy efficacy in triple-negative breast cancer by enhancing cell killing and stimulating immunity

Triple-negative breast cancer (TNBC) is a highly heterogeneous tumor characterized by high recurrence and metastasis, with a very poor prognosis, and there are still great challenges in its clinical treatment. Here, we describe the development of a novel modality for the treatment of TNBC with tumor cell-derived microparticles loaded with paclitaxel (MP-PTX) in combination with radiotherapy. We show that MP can deliver agents to tumor cells by homologous targeting, thereby increasing the absorption rate of the chemotherapeutic agent and enhancing its killing effects on tumor cells. We further demonstrate that MP-PTX combined with radiotherapy shows a synergistic antitumor effect by enhancing the inhibition of tumor cell proliferation, promoting tumor cell apoptosis, reducing the immunosuppressive microenvironment at the tumor site, and activating the antitumor immune response. Altogether, this study provides a referable and optional method for the clinical treatment of refractory tumors such as TNBC based on the combination of T-MP-delivered chemotherapeutic drugs and radiotherapy. Chemical compounds: paclitaxel (PTX), paclitaxel-loaded tumor cell-derived microparticles (MP-PTX).

Clinicopathological characteristics and features of molecular subtypes of breast cancer at high altitudes

Background

Breast cancer is one of the major malignancies threatening women's health worldwide. The incidence of breast cancer at high altitudes increased over the years. But few studies focused on the characteristics of clinicopathology and molecular subtypes among breast cancer at high altitudes, which are still unknown. Tibet, with an average altitude over 4000 meters, is a representative city at high altitudes, lying in the Qinghai-Tibetan Plateau in southwestern China. This study aimed to identify the clinicopathological characteristics and features of molecular subtypes among Tibetan women with breast cancer, and provide evidence for cancer prevention and personalized therapeutics in high-altitude regions.

Methods

Between May 2013 and March 2022, 104 Tibetan women from high-altitude regions (Tibetan-group) and 34 Han Chinese women from low-altitude regions (Han-group), consecutively diagnosed with breast cancer in the Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, were included in the study. We retrospectively reviewed the clinical character, altitudes of residence, tumor size, lymph nodes metastasis, distant metastasis, pathological type, immunohistochemical index, and molecular subtype.

Results

In the study, we calculated the patient delay, equal to the period from symptoms onset to hospital visits. The patient delay of Tibetan-group was 7.47 ± 11.53 months, which was significantly longer than that of Han-group, 7.22 ± 22.96 months (p<0.05). Body Mass Index (BMI) was significantly different (p<0.05). Tumors in Tibetan-group were significantly larger than those in Han-group, 4.13 ± 2.98cm and 2.51 ± 0.82cm in diameter, respectively (p<0.05). According to ordinal logistic regression analysis, exposure to high altitudes might result in more advanced T stage (OR=2.45 95%CI 1.10-5.44). 41.3% (43/104) of cases in Tibetan-group had lymph node positive disease, whereas the percentage was found in 38.26% (13/34) in Han-group(p<0.05). The distribution of molecular subtypes was quite significantly different between two groups (p<0.05), according to the comparison of constituent ratios.

Conclusion

Our study verified that breast cancer at high altitudes possessed its own unique clinicopathological characteristics and distinct features of molecular subtypes. It broadened the understanding of this heterogenous disease and also provided valuable evidence for cancer prevention and personalized therapeutics of breast cancer at high altitudes.

Theranostics for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with poor prognosis. Current endocrine therapy or anti HER-2 therapy is not available for these patients. Chemotherapeutic treatment response varies among patients due to the disease heterogeneity. To overcome these challenges, theranostics for treating TNBC have been widely investigated. Anticancer material conjugated nanoparticles with target-binding ligand and tracer agents enable simultaneous drug delivery and visualization of the lesion with minimal off-target toxicity. In this review, we summarize recently FDA-approved targeted therapies for TNBC, such as poly-ADP-ribose polymerase (PARP) inhibitors, check point inhibitors, and antibody-drug conjugates. Particularly, novel theranostic approaches including lipid-based, polymer-based, and carbon-based nanocarriers are discussed, which can provide basic overview of nano-therapeutic modalities in TNBC diagnosis and treatment.

HER2-positive apocrine carcinoma of the breast: a population-based analysis of treatment and outcome

PURPOSE

Apocrine carcinoma of the breast (APO) expresses HER2 in 30-50% of cases. This study explored the clinicopathological features and outcome of HER2+/APO and matched HER2+/NST cohort.

METHODS

We used the SEER database to explore the cohorts. Univariate and multivariate analyses were used to assess the survival. Based on ER and PR [steroid receptors/SR/] and HER2 status, we divided the cohorts to match the intrinsic molecular subtypes for comparisons.

RESULTS

We retrieved 259 cases of HER2+/APO. Most HER2+/APO were SR negative (65%). HER2+/APO were more prevalent in the 80+ age group (24.7% vs. 15.7%, p < 0.001). HER2+/SR-/APO had a significantly lower histological grade than the HER2+/SR-/NST (p < 0.001). Breast cancer-related deaths were more prevalent in HER2+/NST (7.8% vs. 3.9%, p = 0.019). This was particularly evident between SR- subgroups (10.4% in HER2+/SR-/NST vs. 4.2% in HER2+/SR-/APO, p = 0.008) and was reaffirmed in breast cancer-specific survival in univariate analysis (p = 0.03). Other than race and SR status, HER2+/APO subgroups did not differ in clinicopathological parameters.

CONCLUSIONS

Our study confirms the rarity of the APO and reveals that SR status in APO does not affect these patients' prognosis. HER2+/APO tumors tend to have a less aggressive phenotype and a more favorable outcome despite a markedly lower ER/PR positivity.

A molecular reappraisal of matrix-producing breast metaplastic carcinoma highlighted by PLAG1 and MYC rearrangements

Background:

Very little is currently known about molecular alteration of matrix-producing carcinoma of the breast. However, the morphological similarity with other neoplasm with a myxo-chondroid component is remarkable. In this pilot study we evaluated the molecular alterations involving PLAG1 and MYC genes in 12 cases of matrix producing carcinoma.

Methods:

We evaluated PLAG1 rearrangements as Break-Apart and Gene Copy Gain, and MYC as amplification and polysomy in 12 cases of matrix producing carcinoma using a FISH method.

Results:

Among the 12 cases of matrix producing carcinomas we found that the three cases harboring MYC amplification were all negative for PLAG1 break-apart; four cases with MYC polysomy were associated to PLAG1 break-apart and high Gene Copy Number; among four cases wild type for MYC, three showed a PLAG1- break-apart signal and of them two died with disease. One of the deceased patients showed an amplification of MYC with PLAG1- wild-type and the other showed a PLAG1 break-apart (6%) and a MYC wild-type.

Conclusion:

This is the first report to the best of our knowledge that shows a possible correlation between a matrix producing carcinoma with PLAG1 and MYC involvement in the development and progression of this kind of tumor. We can suppose that MYC amplification behaves in an aggressive way together with PLAG1- break-apart in the cases of matrix producing carcinoma presented here. The gene copy gain is a useful diagnostic tool in the case of difficult diagnosis because an increase was observed in more than 50% of cases.

Special Histologic Type and Rare Breast Tumors - Diagnostic Review and Clinico-Pathological Implications

Breast cancer is the most common malignant tumor in females. While most carcinomas are categorized as invasive carcinoma, no special type (NST), a diverse group of tumors with distinct pathologic and clinical features is also recognized, ranging in incidence from relatively more common to rare. So-called "special histologic type" tumors display more than 90% of a specific, distinctive histologic pattern, while a spectrum of tumors more often encountered in the salivary gland may also arise in the breast. Metaplastic carcinomas can present diagnostic challenges. Some uncommon tumors harbor pathognomonic genetic alterations. This article provides an overview of the key diagnostic points and differential diagnoses for this group of disparate lesions, as well as the salient clinical characteristics of each entity.

Research progress on RNA‑binding proteins in breast cancer (Review)

Breast cancer is the most common malignancy among women, and the abnormal regulation of gene expression serves an important role in its occurrence and development. However, the molecular mechanisms underlying gene expression are highly complex and heterogeneous, and RNA-binding proteins (RBPs) are among the key regulatory factors. RBPs bind targets in an environment-dependent or environment-independent manner to influence mRNA stability and the translation of genes involved in the formation, progression, metastasis and treatment of breast cancer. Due to the growing interest in these regulators, the present review summarizes the most influential studies concerning RBPs associated with breast cancer to elucidate the role of RBPs in breast cancer and to assess how they interact with other key pathways to provide new molecular targets for the diagnosis and treatment of breast cancer.

Molecular Mechanisms, Biomarkers and Emerging Therapies for Chemotherapy Resistant TNBC

Triple-negative breast cancer (TNBC) is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival (OS). Taxane and anthracycline-containing chemotherapy (CT) is currently the main systemic treatment option for TNBC, while platinum-based chemotherapy showed promising results in the neoadjuvant and metastatic settings. An early arising of intrinsic or acquired CT resistance is common and represents the main hurdle for successful TNBC treatment. Numerous mechanisms were uncovered that can lead to the development of chemoresistance. These include cancer stem cells (CSCs) induction after neoadjuvant chemotherapy (NACT), ATP-binding cassette (ABC) transporters, hypoxia and avoidance of apoptosis, single factors such as tyrosine kinase receptors (EGFR, IGFR1), a disintegrin and metalloproteinase 10 (ADAM10), and a few pathological molecular pathways. Some biomarkers capable of predicting resistance to specific chemotherapeutic agents were identified and are expected to be validated in future studies for a more accurate selection of drugs to be employed and for a more tailored approach, both in neoadjuvant and advanced settings. Recently, based on specific biomarkers, some therapies were tailored to TNBC subsets and became available in clinical practice: olaparib and talazoparib for BRCA1/2 germline mutation carriers larotrectinib and entrectinib for neurotrophic tropomyosin receptor kinase (NTRK) gene fusion carriers, and anti-trophoblast cell surface antigen 2 (Trop2) antibody drug conjugate therapy for heavily pretreated metastatic TNBC (mTNBC). Further therapies targeting some pathologic molecular pathways, apoptosis, miRNAS, epidermal growth factor receptor (EGFR), insulin growth factor 1 receptor (IGF-1R), and androgen receptor (AR) are under investigation. Among them, phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and EGFR inhibitors as well as antiandrogens showed promising results and are under evaluation in Phase II/III clinical trials. Emerging therapies allow to select specific antiblastics that alone or by integrating the conventional therapeutic approach may overcome/hinder chemoresistance.

A Novel NIR Fluorescent Nanoprobe Targeting HER2-Positive Breast Cancer: Tra-TTR-A

TTRE, a photosensitizer molecule, has excellent biofluorescence imaging performance and effective antitumor properties for breast cancer. However, its application in breast cancer treatment is limited due to poor tumor selectivity and lack of targeting ability. In this study, TTRE and trastuzumab were combined to synthesize Tra-TTR-A, a novel near-infrared fluorescent nanoprobe for HER2 positive breast cancer. The targeting and antitumor abilities of Tra-TTR-A in breast cancer were also investigated. Like TTRE, Tra-TTR-A has a stable structure with remarkable optical properties and in vivo imaging capacity. However, Tra-TTR-A not only inhibits tumor growth by generating reactive oxygen species but also kills tumor cells by trastuzumab. In this study, Tra-TTR-A, a new type of near-infrared fluorescent nanoprobe that targets HER2-positive breast cancer, was successfully synthesized. Tra-TTR-A could be used in in vivo imaging, targeted photodynamic therapy, and diagnosis and treatment for breast cancer.

FOXC1

CONTEXT.—

Few studies have investigated the features of FOXC1 protein expression in invasive breast cancer subtypes as defined by immunohistochemistry (IHC)-based surrogate molecular classification.

OBJECTIVE.—

To investigate the diagnostic utility of the IHC-based FOXC1 test in breast cancer subtyping and to evaluate the correlation between FOXC1 expression and clinicopathologic parameters in triple-negative breast cancer (TNBC).

DESIGN.—

FOXC1 expression was evaluated with IHC in a large cohort of 2443 patients with breast cancer. Receiver operating characteristic (ROC) curves were used to assess the diagnostic ability of FOXC1 expression to predict the triple-negative phenotype and to identify the best cutoff value. FOXC1 expression was correlated with the clinicopathologic parameters of TNBC.

RESULTS.—

The expression rate of FOXC1 in TNBC was significantly higher than in other subtypes. The area under the ROC curve confirmed the high diagnostic value of FOXC1 for the prediction of the triple-negative phenotype. The cutoff value of 1% showed a maximized sum of sensitivity and specificity. In TNBC, FOXC1 expression was significantly associated with aggressive tumor phenotypes. Furthermore, FOXC1 expression was primarily observed in invasive breast carcinoma of no special type and metaplastic carcinoma but rarely in invasive carcinoma with apocrine differentiation. Correspondingly, FOXC1 expression was significantly associated with the expression of basal markers but was negatively correlated with apocrine-related markers in TNBC.

CONCLUSIONS.—

In conclusion, FOXC1 is a highly specific marker for the triple-negative phenotype. Moreover, immunohistochemical detection of FOXC1 expression can be used as an additional diagnostic tool for the triple-negative phenotype and subclassification in TNBC.

Features from MRI texture analysis associated with survival outcomes in triple-negative breast cancer patients

PURPOSE

The purpose of the study is to evaluate the associations between intratumoral or peritumoral textural features derived from pretreatment magnetic resonance imaging (MRI) and recurrence-free survival (RFS) in triple-negative breast cancer (TNBC) patients.

METHODS

Forty-three patients with TNBC who underwent preoperative MRI between February 2008 and March 2014 were included. We performed two-dimensional texture analysis on the intratumoral or peritumoral region of interest (ROI) on axial of T2-weighted image (T2WI), dynamic contrast-enhanced (DCE)-MRI and DCE-MRI subtraction images. We also analyzed histopathological data. Cox proportional hazards models were used to investigate associations with survival outcomes.

RESULTS

Twelve of the 43 patients (27.9%) had recurrence disease, at a median of 32.5 months follow-up (1.4-61.5 months). In univariate analysis, nine texture features in T2WI and DCE-MRI subtraction images were significantly associated with RFS. In multivariate analysis, intratumoral difference entropy in DCE-MRI subtraction images in the initial phase (hazard ratio 11.71; 95% confidence interval (CI) [1.41, 97.00]; p value 0.023) and, peritumoral difference variance in DCE-MRI subtraction images in the delayed phase (hazard ratio 9.60; 95% CI [1.98, 46.51]; p value 0.005), were both independently associated with RFS. Moreover, multivariate analysis revealed the presence of lymphovascular invasion as independently associated with RFS (hazard ratio 8.13; 95% CI [2.16, 30.30]; p value 0.002).

CONCLUSIONS

At pretreatment MRI, an intratumoral and peritumoral quantitative approach using texture analysis has the potential to serve as a prognostic marker in patients with TNBC.

Immunohistochemical and clinicopathologic features of estrogen receptor-negative, progesterone receptor-positive, HER-2 negative breast carcinomas

OBJECTIVE

Currently, there is an ongoing debate whether progesterone receptor positive and estrogen receptor negative breast carcinomas represent a true distinct subtype of tumor or a mere immunohistochemical artifact. In this study, we conducted an immunohistochemistry panel with the antibodies TFF1, EGFR, and CK5 to reclassify this phenotype in a luminal or basal-like subtype.

METHODS

Tumors estrogen receptor -/progesterone receptor +, Her-2 - from a large population of breast cancer patients were selected to be studied. Immunohistochemistry with the antibodies TFF1, EGFR, and CK5 was performed. Tumors showing positivity for TFF1, regardless of EGFR and CK5 results, were classified as luminal-like carcinomas. Those lesions that were negative for TFF1, but were positive for EGFR and/or CK5, were classified as basal-like triple-negative carcinomas. When the three markers were negative, tumors were classified as undetermined. Clinical pathologic characteristics of patients and tumor recurrence were evaluated.

RESULTS

Out of 1188 breast carcinomas investigated, 30 cases (2.5%) presented the estrogen receptor -/progesterone receptor +/HER2- phenotype. Of them, 27 tumors (90%) were classified as basal-like triple-negative carcinomas, one as luminal-like (3.3%), and two as undetermined tumors (6.7%). The mean follow-up for the study group was 27.7 (2.7 to 50) months. Out of the 26 patients, 6 had cancer recurrence: 2 local and 4 systemic recurrences. The average time for recurrence was 17 (8 to 38) months.

CONCLUSION

Estrogen receptor -/progesterone receptor +/tumors exhibit aggressive behavior, similar to triple-negative tumors. An appropriate categorization of these tumors should be made to improve their therapeutic management.

Lobular Breast Cancer: Histomorphology and Different Concepts of a Special Spectrum of Tumors

Simple Summary

Invasive lobular breast cancer (ILC) is a special type of breast cancer (BC) that was first described in 1941. The diagnosis of ILC is made by microscopy of tumor specimens, which reveals a distinct morphology. This review recapitulates the developments in the microscopic assessment of ILC from 1941 until today. We discuss different concepts of ILC, provide an overview on ILC variants, and highlight advances which have contributed to a better understanding of ILC as a special histologic spectrum of tumors.

Abstract

Invasive lobular breast cancer (ILC) is the most common special histological type of breast cancer (BC). This review recapitulates developments in the histomorphologic assessment of ILC from its beginnings with the seminal work of Foote and Stewart, which was published in 1941, until today. We discuss different concepts of ILC and their implications. These concepts include (i) BC arising from mammary lobules, (ii) BC growing in dissociated cells and single files, and (iii) BC defined as a morpho-molecular spectrum of tumors with distinct histological and molecular characteristics related to impaired cell adhesion. This review also provides a comprehensive overview of ILC variants, their histomorphology, and differential diagnosis. Furthermore, this review highlights recent advances which have contributed to a better understanding of the histomorphology of ILC, such as the role of the basal lamina component laminin, the molecular specificities of triple-negative ILC, and E-cadherin to P-cadherin expression switching as the molecular determinant of tubular elements in CDH1-deficient ILC. Last but not least, we provide a detailed account of the tumor microenvironment in ILC, including tumor infiltrating lymphocyte (TIL) levels, which are comparatively low in ILC compared to other BCs, but correlate with clinical outcome. The distinct histomorphology of ILC clearly reflects a special tumor biology. In the clinic, special treatment strategies have been established for triple-negative, HER2-positive, and ER-positive BC. Treatment specialization for patients diagnosed with ILC is just in its beginnings. Accordingly, ILC deserves greater attention as a special tumor entity in BC diagnostics, patient care, and cancer research.

Triple-negative breast lobular carcinoma: a luminal androgen receptor carcinoma with specific ESRRA mutations

Primary triple-negative invasive lobular breast carcinomas (TN-ILCs), which do not express hormone receptors and HER2 at diagnosis, are rare and poorly known. In this study, we analyzed the largest TN-ILC series ever reported in the literature, in comparison to phenotypically similar breast tumor subtypes: triple-negative invasive ductal carcinoma (TN-IDC) and hormone receptor-positive invasive lobular carcinoma (HR + ILC). All primary TN-ILCs registered in our database between 2000 and 2018 (n = 38) were compared to tumors from control groups, matched by stage and Elston/Ellis grade, with regard to clinical, pathologic, and immunohistochemical characteristics. A comparative molecular analysis (whole-exome and RNA sequencing using next-generation technology) was also performed. We found that TN-ILC patients were older than those with HR + ILC (P = 0.002) or TN-IDC (P < 0.001). Morphologically, TN-ILCs had aggressive phenotypes, with more pleomorphism (P = 0.003) and higher nuclear grades than HR + ILCs (P = 0.009). Immunohistochemistry showed that TN-ILCs less frequently expressed basal markers (CK5/6, EGFR and SOX10) than TN-IDCs (P < 0.001), while androgen receptor (AR) positivity was more prevalent (P < 0.001). Survival curves analysis did not show differences between TN-ILC and TN-IDC patients, while overall and distant metastasis-free survival were significantly worse compared to those with HR + ILCs (P = 0.047 and P = 0.039, respectively). At a molecular level, we found that TN-ILCs had particular transcriptomic profiles, characterized by increased AR signaling, and associated with frequent alterations in the PI3K network and ERBB2. Interestingly, whole-exome analysis also identified three specific recurrent ESRRA hotspot mutations in these tumors, which have never been described in breast cancer to date and which were absent in the other two tumor subtypes. Our findings highlight that TN-ILC is a unique aggressive breast cancer associated with elderly age, which belong to the luminal androgen receptor subtype as determined by immunohistochemistry and transcriptomic profiling. Moreover, it harbors specific molecular alterations (PI3K, ERBB2 and ESRRA) which may pave the way for new targeted therapeutic strategies.

HDAC6 inhibition enhances the anti-tumor effect of eribulin through tubulin acetylation in triple-negative breast cancer cells

PURPOSE

Improved prognosis for triple-negative breast cancer (TNBC) has plateaued and the development of novel therapeutic strategies is required. This study aimed to explore the anti-tumor effect of combined eribulin and HDAC inhibitor (vorinostat: VOR, pan-HDAC inhibitor and ricolinostat: RICO, selective HDAC6 inhibitor) treatment for TNBC.

METHODS

The effect of eribulin in combination with an HDAC inhibitor was tested in three TNBC cell lines (MDA-MB-231, Hs578T, and MDA-MB-157) and their eribulin-resistant derivatives. The expression of acetylated α-tubulin was analyzed by Western blotting for TNBC cells and immunohistochemical analyses for clinical specimens obtained from breast cancer patients who were treated with eribulin.

RESULTS

The simultaneous administration of low concentrations (0.2 μM) of VOR or RICO enhanced the anti-tumor effect of eribulin in MDA-MB-231 and Hs578T cells but not in MDA-MB-157 cells. Meanwhile, pretreatment with 5 μM of VOR or RICO enhanced eribulin sensitivity in all three cell lines. Low concentration of VOR or RICO increased acetylated α-tubulin expression in MDA-MB-231 and Hs578T cells. In contrast, whereas 5 μM of VOR or RICO increased the expression of acetylated α-tubulin in MDA-MB-157 cells, low concentrations did not. Eribulin increased the expression of acetylated α-tubulin in MDA-MB-231 and Hs578T cells but not in MDA-MB-157 cells. These phenomena were also observed in eribulin-resistant cells. Immunohistochemical analyses revealed that the expression of acetylated α-tubulin was increased after eribulin treatment in TNBC.

CONCLUSIONS

HDAC6 inhibition enhances the anti-tumor effect of eribulin through the acetylation of α-tubulin. This combination therapy could represent a novel therapeutic strategy for TNBC.

Triple-negative apocrine carcinoma: A rare pathologic subtype with a better prognosis than other triple-negative breast cancers

BACKGROUND AND METHODS

Apocrine adenocarcinoma is a rare subtype of breast cancer. We sought to compare the characteristics and survival of patients diagnosed with triple-negative apocrine adenocarcinoma to those of patients diagnosed with triple-negative invasive ductal carcinoma. Utilizing data from the National Cancer Database between 2004 and 2013, 70 524 eligible female patients with triple-negative breast cancer were identified including 566 patients with apocrine adenocarcinomas and 69 958 patients with invasive ductal carcinoma. Descriptive statistics for each variable were reported. A comparison of each covariate between the study cohorts was assessed in univariate and multivariate analysis. Cox proportional models were used to calculate hazard ratios. Additionally, the propensity score matching method was implemented to reduce treatment selection bias.

RESULTS

Patients with triple-negative apocrine tumors were more likely to be older, Caucasian, and have smaller, moderately to well-differentiated tumors. Multivariable analysis noted a significantly improved survival for patients with triple-negative apocrine carcinoma (TNAC) vs triple-negative invasive ductal carcinoma (TNBC) (hazard ratio [HR] 0.65 [95% confidence interval [CI] [0.53-0.81], P = 0 < .001). Propensity score matching analysis confirmed a significant difference in overall survival for patients with TNAC in comparison to TNBC (HR 0.79 [95% CI [0.63-1.00], P = .05).

DISCUSSION

Triple-negative apocrine adenocarcinomas have a modestly improved long-term survival when compared with triple-negative invasive ductal cancers.

Clinicopathological characteristics and prognosis of breast cancer with special histological types: A surveillance, epidemiology, and end results database analysis

Objectives

To explore the clinicopathological features and prognosis of breast cancer with special histological types.

Materials and methods

The information of breast cancer patients was obtained from the Surveillance, Epidemiology, and End Results (SEER) database (2010–2016). Comparative analyses were performed to explore the difference in clinicopathological characteristics and propensity score matching (PSM) was used to weaken the effects from clinical profiles. Survival analysis was conducted to investigate the prognostic effects from histological types, and the prognostic factors of this group of patients were identified with the univariate COX proportional model.

Results

A total of 242863 breast cancer patients were eligible, of which 230213 individuals were ductal breast cancer (IDC) and 12650 individuals were special breast lesions, respectively. Comparatively, special breast cancer had a lower histological grade, a smaller tumor size, a lower proportion of nodal involvement and distant metastasis, in addition to a higher proportion of triple-negative subtype. The overall prognosis of special histological breast cancer was comparable to IDC, while the survival of HER2 enriched breast cancer was in favor of special breast cancer. With the PSM performance, the prognosis exhibited an inferior profile in the metaplastic breast cancer and was significantly favorable to apocrine, medullary, micropapillary, and papillary breast cancer.

Conclusion

This study revealed that the special histological breast cancer presented distinct clinicopathological characteristics and great heterogeneity in the prognosis among diverse histological subtypes.

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Breast cancer is a heterogenous disease with diverse histological subtypes.

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Special histological breast cancer exhibits distinct clinicopathological profiles.

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Prognosis of special histological breast cancer is profoundly heterogenous.

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Histological subtype is an independent prognostic indicator of breast cancer.

Prognosis of selected triple negative apocrine breast cancer patients who did not receive adjuvant chemotherapy

Background

Triple negative breast cancer encompasses several biological entities with different outcomes and is a priority to identify which patients require more treatment to reduce the risk of recurrence and which patients need less treatment.

Patients and methods

Among the 210 women with first primary invasive apocrine non metastatic breast cancer operated on between January 1998 and December 2016 at the European Institute Oncology, Milan, we identified 24 patients with a pT1-pT2, node-negative, triple negative subtype and Ki-67 ≤ 20% who did not receive adjuvant chemotherapy (CT). We compared the outcome of this cohort with a similar group of 24 patients with ductal tumors who received adjuvant chemotherapy, matched by pathological stage and biological features and also with a similar group of 12 patients with apocrine tumors who received adjuvant chemotherapy.

Results

The median age was 64 and 61 years in the apocrine (w/o CT) and ductal group, respectively. The median value of Ki-67 expression was 12% in the apocrine group (w/o CT) and 16% in the ductal group (p < 0.001). After a median follow-up of 7.5 years, no patients in the apocrine group (w/o CT) experienced a breast cancer related event compared with 4 events in the ductal carcinoma group (Gray test p-value = 0.11).

Conclusions

The outcome of selected apocrine triple negative breast cancer patients who did not received adjuvant chemotherapy is excellent and supports a treatment de-escalation. Multicenter projects focusing on the possibility of avoiding adjuvant chemotherapy in selected subtypes of triple negative breast cancers with favorable outcome are warranted.

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Triple negative breast cancer is a eterogeneous disease.

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The outcome of selected apocrine triple negative breast cancer patients is excellent despite the omission of chemotherapy.

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A treatment de-escalation should be discussed.

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Multicenter projects focusing on selected subtypes of triple negative breast cancers are warranted.

Histologic subtyping affecting outcome of triple negative breast cancer: a large Sardinian population-based analysis

BACKGROUND

Triple Negative breast cancer (TNBC) includes a heterogeneous group of tumors with different clinico-pathological features, molecular alterations and treatment responsivity. Our aim was to evaluate the clinico-pathological heterogeneity and prognostic significance of TNBC histologic variants, comparing "special types" to high-grade invasive breast carcinomas of no special type (IBC-NST).

METHODS

This study was performed on data obtained from TNBC Database, including pathological features and clinical records of 1009 TNBCs patients diagnosed between 1994 and 2015 in the four most important Oncology Units located in different hospitals in Sardinia, Italy. Kaplan-Meier analysis, log-rank test and multivariate Cox proportional-hazards regression were applied for overall survival (OS) and disease free survival (DFS) according to TNBC histologic types.

RESULTS

TNBC "special types" showed significant differences for several clinico-pathological features when compared to IBC-NST. We observed that in apocrine carcinomas as tumor size increased, the number of metastatic lymph nodes manifestly increased. Adenoid cystic carcinoma showed the smallest tumor size relative to IBC-NST. At five-year follow-up, OS was 92.1, 100.0, and 94.5% for patients with apocrine, adenoid cystic and medullary carcinoma, respectively; patients with lobular and metaplastic carcinoma showed the worst OS, with 79.7 and 84.3%, respectively. At ten-years, patients with adenoid cystic (100.0%) and medullary (94.5%) carcinoma showed a favourable prognosis, whereas patients with lobular carcinoma showed the worst prognosis (73.8%). TNBC medullary type was an independent prognostic factor for DFS compared to IBC-NST.

CONCLUSIONS

Our study confirms that an accurate and reliable histopathologic definition of TNBC subtypes has a significant clinical utility and is effective in the therapeutic decision-making process, with the aim to develop innovative and personalized treatments.

TIMP-2 suppresses tumor growth and metastasis in murine model of triple-negative breast cancer

Metastasis is the primary cause of treatment failures and mortality in most cancers. Triple-negative breast cancer (TNBC) is refractory to treatment and rapidly progresses to disseminated disease. We utilized an orthotopic mouse model that molecularly and phenotypically resembles human TNBC to study the effects of exogenous, daily tissue inhibitor of metalloproteinase-2 (TIMP-2) treatment on tumor growth and metastasis. Our results demonstrated that TIMP-2 treatment maximally suppressed primary tumor growth by ~36-50% and pulmonary metastasis by >92%. Immunostaining assays confirmed disruption of the epithelial to mesenchymal transition (EMT) and promotion of vascular integrity in primary tumor tissues. Immunostaining and RNA sequencing analysis of lung tissue lysates from tumor-bearing mice identified significant changes associated with metastatic colony formation. Specifically, TIMP-2 treatment disrupts periostin localization and critical cell-signaling pathways, including canonical Wnt signaling involved in EMT, as well as PI3K signaling, which modulates proliferative and metastatic behavior through p27 phosphorylation/localization. In conclusion, our study provides evidence in support of a role for TIMP-2 in suppression of triple-negative breast cancer growth and metastasis through modulation of the epithelial to mesenchymal transition, vascular normalization, and signaling pathways associated with metastatic outgrowth. Our findings suggest that TIMP-2, a constituent of the extracellular matrix in normal tissues, may have both direct and systemic antitumor and metastasis suppressor effects, suggesting potential utility in the clinical management of breast cancer progression.

Quantitative proteomic landscape of metaplastic breast carcinoma pathological subtypes and their relationship to triple-negative tumors

Metaplastic breast carcinoma (MBC) is a highly aggressive form of triple-negative cancer (TNBC), defined by the presence of metaplastic components of spindle, squamous, or sarcomatoid histology. The protein profiles underpinning the pathological subtypes and metastatic behavior of MBC are unknown. Using multiplex quantitative tandem mass tag-based proteomics we quantify 5798 proteins in MBC, TNBC, and normal breast from 27 patients. Comparing MBC and TNBC protein profiles we show MBC-specific increases related to epithelial-to-mesenchymal transition and extracellular matrix, and reduced metabolic pathways. MBC subtypes exhibit distinct upregulated profiles, including translation and ribosomal events in spindle, inflammation- and apical junction-related proteins in squamous, and extracellular matrix proteins in sarcomatoid subtypes. Comparison of the proteomes of human spindle MBC with mouse spindle (CCN6 knockout) MBC tumors reveals a shared spindle-specific signature of 17 upregulated proteins involved in translation and 19 downregulated proteins with roles in cell metabolism. These data identify potential subtype specific MBC biomarkers and therapeutic targets.

Metaplastic breast carcinoma (MBC) is among the most aggressive subtypes of triple-negative breast cancer (TNBC) but the underlying proteome profiles are unknown. Here, the authors characterize the protein signatures of human MBC tissue samples and their relationship to TNBC and normal breast tissue.

Molecular subtypes and precision treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Despite the progress made in precision treatment of cancer patients, targeted treatment is still at its early stage in TNBC, and chemotherapy remains the standard treatment. With the advances in next generation sequencing technology, genomic and transcriptomic analyses have provided deeper insight into the inter-tumoral heterogeneity of TNBC. Much effort has been made to classify TNBCs into different molecular subtypes according to genetic aberrations and expression signatures and to uncover novel treatment targets. In this review, we summarized the current knowledge regarding the molecular classification of TNBC and explore the future paradigm for using molecular classification to guide the development of precision treatment and clinical practice.

Histological subtypes in triple negative breast cancer are associated with specific information on survival

Much research has focused on finding novel prognostic biomarkers for triple negative breast cancer (TNBC), whereas only scattered information about the relation between histopathological features and survival in TNBC is available. This study aims to explore the prognostic value of histological subtypes in TNBC. A multicenter retrospective TNBC cohort was established from five Dutch hospitals. All non-neoadjuvantly treated, stage I-III patients with estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 negative breast cancer diagnosed between 2006 and 2014 were included. Clinical and follow-up data (overall survival; OS, relapse free survival; RFS) were retrieved and a central histopathological review was performed. Of 597 patients included (median follow up 62.8 months, median age at diagnosis 56.0 years), 19.4% developed a recurrence. The most prevalent histological subtypes were carcinoma of no special type (NST) (88.4%), metaplastic carcinoma (4.4%) and lobular carcinoma (3.4%). Collectively, tumors of special type were associated with a worse RFS and OS compared to carcinoma NST (RFS HR 1.89; 95% CI 1.18-3.03; p = 0.008; OS HR 1.94; 95% CI 1.28-2.92; p = 0.002). Substantial differences in survival, however, were present between the different histological subtypes. In the presented TNBC cohort, special histological subtype was in general associated with less favorable survival. However, within the group of tumors of special type there were differences in survival between the different subtypes. Accurate histological examination can provide specific prognostic information that may potentially enable more personalized treatment and surveillance regimes for TNBC patients.

Development and Validation of Nomograms for Predicting the Prognosis of Triple-Negative Breast Cancer Patients Based on 379 Chinese Patients

PURPOSE

We aimed to construct universally applicable nomograms incorporating prognostic factors to predict the prognosis of patients with triple-negative breast cancer (TNBC).

PATIENTS AND METHODS

Clinicopathological data of 379 patients with TNBC from March 2008 to June 2014 were retrospectively collected and analyzed. The endpoints were disease-free survival (DFS) and overall survival (OS). Patients were randomly divided into a training group and an independent validation group. In the training group, the prognostic factors were screened to develop nomograms. C-index and calibration curves were used to evaluate the predictive accuracy and discriminative ability of nomograms in both groups. The accuracy of the nomograms was also compared with the traditional American Joint Committee on Cancer Tumor-Node-Metastasis anatomical stage (8th edition).

RESULTS

Four prognostic factors (albumin-to-globulin ratio, neutrophil-to-lymphocyte ratio, positive lymph nodes, and tumor size) were used to construct the nomogram of DFS. In addition to the aforementioned factors, age was taken into account in the construction of the OS nomogram. The C-index of the DFS nomogram in the training and validation groups was 0.71 (95% confidence interval [CI]: 0.64-0.77) and 0.69 (95% CI: 0.58-0.79), respectively; the C-index of the OS nomogram was 0.77 (95% CI: 0.70-0.84) and 0.74 (95% CI: 0.62-0.86), respectively. This suggests that the nomograms had high accuracy. Moreover, calibration curves showed good consistencies in both groups. Our models showed superiority in predicting accuracy compared with the AJCC TNM staging system. Furthermore, two web pages of the nomograms were produced: DFS: https://sh-skipper.shinyapps.io/TNBC1/; OS: https://sh-skipper.shinyapps.io/TNBC2/.

CONCLUSION

These predictive models are simple and easy to use, particularly the web versions. They have certain clinical value in predicting the prognosis of patients with TNBC. They can assist doctors in identifying patients at different prognostic risks and strengthen the treatment or follow-up accordingly.

FA2H Exhibits Tumor Suppressive Roles on Breast Cancers via Cancer Stemness Control

Background: Triple negative breast cancers are aggressive, enriched with cancer stem cells, and lack effective targeted therapies with little side effects. Methods: We isolated cancer stem cells from two triple negative breast cancer cell lines via cell sorting following transcriptome sequencing, bioinformatics analysis, experimental and clinical validations, as well as functional investigations to explore genes capturing triple negative breast cancer features for improved diagnosis and therapeutics in clinics. Results: We found that FA2H is under-expressed in triple negative breast cancers both in vitro and in clinics, and FA2H suppresses cancer stemness via inhibiting the STAT3/IL6 axis and NFkB signaling. Conclusions: This study reports the tumor suppressive roles of FA2H on breast cancer cells through cancer stemness control. FA2H and other candidates unveiled in this study that capture the features of cancer stem cells may contribute as diagnostic marker and/or effective therapeutic targets for improved triple negative breast cancer management.

An Orally Available Tubulin Inhibitor, VERU-111, Suppresses Triple-Negative Breast Cancer Tumor Growth and Metastasis and Bypasses Taxane Resistance

Triple-negative breast cancer (TNBC) accounts for approximately 15% of breast cancer cases in the United States. TNBC has poorer overall prognosis relative to other molecular subtypes due to rapid onset of drug resistance to conventional chemotherapies and increased risk of visceral metastases. Taxanes like paclitaxel are standard chemotherapies that stabilize microtubules, but their clinical efficacy is often limited by drug resistance and neurotoxicities. We evaluated the preclinical efficacy of a novel, potent, and orally bioavailable tubulin inhibitor, VERU-111, in TNBC models. VERU-111 showed potent cytotoxicity against TNBC cell lines, inducing apoptosis and cell-cycle arrest in a concentration-dependent manner. VERU-111 also efficiently inhibited colony formation, cell migration, and invasion. Orally administered VERU-111 inhibited MDA-MB-231 xenograft growth in a dose-dependent manner, with similar efficacies to paclitaxel, but without acute toxicity. VERU-111 significantly reduced metastases originating from the mammary fat pad into lung, liver, and kidney metastasis in an experimental metastasis model. Moreover, VERU-111, but not paclitaxel, suppressed growth of luciferase-labeled, taxane-resistant, patient-derived metastatic TNBC tumors. In this model, VERU-111 repressed growth of preestablished axillary lymph node metastases and lung, bone, and liver metastases at study endpoint, whereas paclitaxel enhanced liver metastases relative to vehicle controls. Collectively, these studies strongly suggest that VERU-111 is not only a potent inhibitor of aggressive TNBC phenotypes, but it is also efficacious in a taxane-resistant model of metastatic TNBC. Thus, VERU-111 is a promising new generation of tubulin inhibitor for the treatment of TNBC and may be effective in patients who progress on taxanes.Results presented in this study demonstrate the efficacy of VERU-111 in vivo and provide strong rationale for future development of VERU-111 as an effective treatment for metastatic breast cancer.

Deep learning and manual assessment show that the absolute mitotic count does not contain prognostic information in triple negative breast cancer

PURPOSE

The prognostic value of mitotic count for invasive breast cancer is firmly established. As yet, however, limited studies have been aimed at assessing mitotic counts as a prognostic factor for triple negative breast cancers (TNBC). Here, we assessed the prognostic value of absolute mitotic counts for TNBC, using both deep learning and manual procedures.

METHODS

A retrospective TNBC cohort (n = 298) was used. The absolute manual mitotic count was assessed by averaging counts from three independent observers. Deep learning was performed using a convolutional neural network on digitized H&E slides. Multivariable Cox regression models for relapse-free survival and overall survival served as baseline models. These were expanded with dichotomized mitotic counts, attempting every possible cut-off value, and evaluated by means of the c-statistic.

RESULTS

We found that per 2 mm2 averaged manual mitotic counts ranged from 1 to 187 (mean 37.6, SD 23.4), whereas automatic counts ranged from 1 to 269 (mean 57.6; SD 42.2). None of the cut-off values improved the models' baseline c-statistic, for both manual and automatic assessments.

CONCLUSIONS

Based on our results we conclude that the level of proliferation, as reflected by mitotic count, does not serve as a prognostic factor for TNBC. Therefore, TNBC patient management based on mitotic count should be discouraged.

A Review of the Hereditary Component of Triple Negative Breast Cancer: High- and Moderate-Penetrance Breast Cancer Genes, Low-Penetrance Loci, and the Role of Nontraditional Genetic Elements

Triple negative breast cancer (TNBC), representing 10-15% of breast tumors diagnosed each year, is a clinically defined subtype of breast cancer associated with poor prognosis. The higher incidence of TNBC in certain populations such as young women and/or women of African ancestry and a unique pathological phenotype shared between TNBC and BRCA1-deficient tumors suggest that TNBC may be inherited through germline mutations. In this article, we describe genes and genetic elements, beyond BRCA1 and BRCA2, which have been associated with increased risk of TNBC. Multigene panel testing has identified high- and moderate-penetrance cancer predisposition genes associated with increased risk for TNBC. Development of large-scale genome-wide SNP assays coupled with genome-wide association studies (GWAS) has led to the discovery of low-penetrance TNBC-associated loci. Next-generation sequencing has identified variants in noncoding RNAs, viral integration sites, and genes in underexplored regions of the human genome that may contribute to the genetic underpinnings of TNBC. Advances in our understanding of the genetics of TNBC are driving improvements in risk assessment and patient management.

Comparative prognostic analysis for triple-negative breast cancer with metaplastic and invasive ductal carcinoma

AIMS

Triple-negative breast cancer comprises different histological subtypes, including metaplastic breast cancer (MBC) and ductal carcinomas (IDCs). The purpose of this study was to compare triple-negative MBC (TN-MBC) with triple-negative IDC (TN-IDC) in terms of survival and predictive factors.

METHODS

With access to the Surveillance, Epidemiology and End Result (SEER) database, a total of 19 383 patients met the eligibility criteria. Clinicopathological characteristics were compared between groups using the χ² test. Univariate and multivariate analyses were applied to evaluate the disease-specific survival (DSS) and overall survival (OS). Subgroup analyses summarised the hazard ratios of TN-MBC versus TN-IDC using a forest plot.

RESULTS

A total of 586 patients with TN-MBC and 18 797 with TN-IDC were included in this study. Patients with TN-MBC were older and presented with larger tumour sizes, relatively rare lymph node positive disease, and had received more chemotherapy. Compared with TN-IDC, the TN-MBC group showed a significantly poorer prognosis before and after the 1:3 matched case-control analysis. Further subgroup analysis indicated that patients with TN-MBC were older, were from specific races, and those with distant metastasis and not receiving radiotherapy had worse prognosis than patients with TN-IDC in terms of DFS and OS.

CONCLUSION

Our results showed that patients with TN-MBC had unique clinicopathological characteristics and poorer prognostic subtype compared with TN-IDC. This improves our understanding of the clinicopathological and prognostic features of this rare entity but also provides more convincing therapeutic guidelines for TN-MBC in patients with breast cancer.

Breast Carcinoma: Updates in Molecular Profiling 2018

The most significant contribution of molecular subtyping of breast carcinomas has been the identification of estrogen-positive and estrogen-negative tumor subtypes. Knowledge of genetic alterations in these tumors will help clinicians identify novel therapeutic targets. Understanding the progression pathways involved in the transition of in situ carcinoma to invasive carcinoma might lead to efficient risk stratification in these patients. The Cancer Genome Analysis Network has collected genomic and epigenomic data to provide comprehensive information regarding carcinogenesis and pathway interactions. Such information improves understanding of the disease process and also provides more accurate information toward identifying targetable mutations for treatment.

Synchronous Ovarian and Breast Cancers with a Novel Variant in BRCA2 Gene: A Case Report

We report a case of a 52-year-old female with a family history of pancreatic and colon cancers who presented with a right breast mass positive for high-grade medullar carcinoma with triple-negative biomolecular profile. Further workup was performed finding a left ovarian mass. The patient underwent laparotomy performing optimal cytoreduction on bilateral ovarian tumors; the pathology and immunohistochemistry confirmed bilateral ovary adenocarcinoma with positive peritoneal malignancy. Due to her synchronic breast and ovarian cancers, a genetic profile was performed detecting a new pathogenic variant in the BRCA2 gene: c.3606_3607del (p.Ser1203Cysfs). She was given chemotherapy with carboplatin and paclitaxel obtaining complete clinical response. Regarding her breast cancer, she had a right modified radical mastectomy and prophylactic left mastectomy obtaining complete clinical response. This case presents with an unusual subtype and difficult histologic diagnosis of a synchronic medullar breast cancer and ovary carcinoma associated with a new mutation of the BRCA2 gene.

Development and validation of nomograms for predicting overall and breast cancer-specific survival among patients with triple-negative breast cancer

Purpose

TNBC is generally more aggressive than other BC subtypes and has limited therapeutic options. We aimed to construct comprehensive and reliable nomograms to predict the OS and BCSS of TNBC patients to offer clinicians therapeutic guidance for improving the prognosis of TNBC patients.

Patients and methods

We used the SEER 19 Cancer Registry to identify 21,419 eligible TNBC patients diagnosed from January 1, 2010 to December 31, 2015, and divided the database randomly into a training cohort (n=10,709) and a validation cohort (n=10,710). The log-rank test and Cox analysis together with a competing risk model were utilized to identify independent prognostic factors for OS and BCSS, which were then integrated to construct nomograms.

Results

According to the training cohort, except for laterality, the following factors were all predictive of OS and BCSS: age at diagnosis, race, tumor size, number of positive lymph nodes, grade, and histological subtype. The 1-, 3-, and 5-year probabilities of BC-specific mortality were 2.7%, 12.5%, and 17.1%, respectively. The precision of the nomograms was assessed by the C-index value and calibration plot diagrams. The C-index value were 0.779 for OS and 0.793 for BCSS in the internal validation and 0.774 for OS and 0.792 for BCSS in the external validation. Both internal and external calibration plot diagrams showed good consistency between the actual and predicted outcomes, especially for 3- and 5-year OS and BCSS.

Conclusion

These nomograms hold promise as a novel and accurate tool in predicting OS and BCSS of TNBC patients and could be used in clinical practice to assist clinicians in developing more effective therapeutic strategies and to evaluate prognostic personally.

Prognosis in different subtypes of metaplastic breast cancer: a population-based analysis

BACKGROUND

Metaplastic breast cancer (MpBC) is a rare histological subtype of breast cancer recognized as a unique pathologic entity in 2000. However, the pathogenesis, optimal therapy, and prognosis of MpBC and the potential effect of systemic treatments on different subtypes of MpBC are not well defined.

METHODS

A retrospective population-based study was performed to identify breast cancer patients with MpBC and other triple-negative breast cancers (TNBC) between 2010 and 2014 using the surveillance, Epidemiology, and End Results (SEER) database. Chi-square test was used to analyze characteristics between subgroups. Kaplan-Meier analysis and Multivariate Cox regressions were used to evaluate overall survival (OS) of MpBC, TNBC, and MpBC subgroups. Competing risk analysis and multivariate regression model of competing risk were used to assess breast cancer-specific survival (BCSS) of MpBC and TNBC RESULTS: We identified a study cohort of 22,433 patients (1112 MpBC and 21,321 TNBC). MpBC correlated with older population, larger tumor size and less lymph node involvement, and TNBC phenotype. Patients with MpBC especially with triple-negative subtype (TN-MpBC) had worse survival than the overall TNBC population. However, the prognosis of MpBC without triple-negative subtype (non-TN MpBC) was not different from that of TNBC. In Kaplan-Meier analysis, chemotherapy was not associated with significant difference in OS of TN-MpBC. In non-TN MpBC group, the 3-year OS was 79.8% for patients receiving chemotherapy and 70.5% in patients without chemotherapy, and chemotherapy was associated (P = 0.033) with improved OS. Within the MpBC patients, radiotherapy was significantly (HR 1.544; 95% CI 1.148-2.078; P = 0.004) associated with improved OS and (HR 1.474; 95% CI 1.067-2.040; P = 0.019) BCSS.

CONCLUSIONS

Patients with TN-MpBC had worse prognosis than TNBC and chemotherapy was not associated with improved survival. In contrast, non-TN MpBC may derive survival benefit from chemotherapy and radiotherapy.

The downregulation of WWOX induces epithelial-mesenchymal transition and enhances stemness and chemoresistance in breast cancer

IMPACT STATEMENT

Overcoming resistance to chemotherapy is one of the fundamental issues of clinical treatment and CSCs are responsible for the poor therapeutic effects of chemotherapy. WW domain-containing oxidoreductase (WWOX), an important tumor suppressor, regulates cancer cells' response to chemotherapy. The major finding of our study is the novel role of WWOX in the chemoresistance of breast cancer through the regulation of cell stemness and EMT. The plasticity may play a crucial role in tumor metastasis, treatment resistance and tumor recurrence. Our findings may shed new light on the alterations of BCSCs and pave the way for the discovery of novel and more effective therapies to treat breast cancer by targeting WWOX.

Survival Study of Triple-Negative and Non-Triple-Negative Breast Cancer in a Brazilian Cohort

OBJECTIVE

To analyze the clinical, pathological, and sociodemographic aspects between triple-negative breast cancer (TNBC) and non-TNBC in a Brazilian cohort and identify potential prognostic factors.

METHODS

This hospital-based retrospective cohort study included 447 women with breast cancer treated at referral centers in Southeastern Brazil. Overall and disease-free survival were compared; prognostic factors were evaluated.

RESULTS

Triple-negative breast cancer corresponded to 19.5% of breast cancer diagnosis and was more prevalent among nonwhite and less educated women. The patients with TNBC tended to present with stage III cancer, high p53 expression, lymphocytic infiltration, and multifocality and treated with radical surgery and chemotherapy. The 5-year overall and disease-free survival were 62.1% and 57.5% for TNBC and 80.8% and 75.3% for non-TNBC, respectively (P < .001). The TNBC recurrence was associated with multicentricity, whereas lymph node involvement increased the risk of both recurrence and death. Non-TNBC worse clinical course was associated with nonwhite ethnicity, lower education level, lymph node involvement, and advanced stage.

CONCLUSIONS

Triple-negative breast cancer exhibited a more aggressive behavior, earlier and more frequent recurrence, and worse survival compared with non-TNBC. While biological and social variables were associated with poorer prognosis in non-TNBC, only lymph node involvement and multicentricity were correlated with worse clinical outcomes in TNBC.

Medullary Breast Carcinoma and Invasive Ductal Carcinoma: A Review Study

BACKGROUND

Medullary breast carcinoma (MBC) is a unique histological subtype of breast cancer. The present study aimed to evaluate the classic and non-classic characteristics of MBC and its differences with IDC. The present review study incorporates 22 years of practical experience from a breast disease research center-based series of cases.

METHODS

Retrospectively, the medical records of 3,246 patients were reviewed in the Breast Disease Research Center, Shiraz University of Medical Science (Shiraz, Iran), from December 1993 to December 2015. The tumor size, lymph node metastasis, pathologic stage, nuclear and histological grade, hormonal receptor status, recurrence, disease-free, and overall survival were reviewed. Differences between medullary breast carcinoma and invasive ductal carcinoma were analyzed statistically using the Chi-square, Fischer, independent-sample t test, and Kaplan-Meier analysis (SPSS version 19.0). P<0.05 were considered statistically significant.

RESULTS

A total of 179 patients were identified with MBC and 3,067 patients were identified with IDC. The MBC group had a significant association with a higher histological grade (P<0.001) as well as negative estrogen receptor (P<0.001), progesterone receptor (P<0.001), and HER-2 (P=0.004) status. The MBC patients predominantly had triple-negative breast cancer (TNBC) according to the molecular subtype (P<0.001). In local invasion, MBC was less invasive compared to IDC (P<0.001). The disease-free survival (DFS) and overall survival (OS) differed significantly between the MBC and IDC groups (5-year DFS: 94.2% vs. 86.3%, P=0.008; 5-year OS: 98.1% vs. 92.8%, P=0.004).

CONCLUSION

Despite the poor and aggressive pathological features of MBC, its clinical outcome is more favorable compared to IDC. Our findings can be useful in improvement of diagnosis and treatment of less known breast cancer subtypes, such as MBC.