Rare Subtype Of Breast Cancer Research Articles

Abstract PD4-07: PD4-07 Uncovering molecular heterogeneity of mixed ductal and lobular carcinoma using digital spatial profiling

Abstract Background Mixed invasive ductal and lobular carcinoma (mDLC) is a rare special subtype (3-6%, ~10,000 cases/annually in US) of invasive breast cancer with elusive pathophysiology. This entity exhibits a mix of ductal-like and lobular-like tumor sub-components within the same tumor. With few seminal studies, mDLC remains poorly understood with little molecular understanding of its sub-components including their origin and implications on disease evolution, prognosis, and treatment response. With increasing recognition of no special type (NST) and invasive lobular carcinoma (ILC) as distinct diseases with unique biology, it is important to understand whether this mixed entity, and its sub-components are like NST and ILC subtypes or a distinct disease. Methods We identified mDLC cases from the UPMC cancer registry. These underwent comprehensive evaluation by a panel of expert pathologists. Three cases (each with a ductal and lobular sub-component on the same FFPE block) were shortlisted. These cases underwent digital spatial profiling (DSP) using Nanostring GeoMX Human Whole Transcriptome Atlas. Briefly, 5um slides were stained using RNAscope morphology marker probes (E-cadherin and PanCK) and GeoMX DSP oligo-conjugated RNA detection probes. Between 3-6 ductal and lobular regions of interest (ROI) per tumor were selected by pathologists. DSP barcodes were cleaved off using UV light and collected into 96-well plate. These underwent library preparation and sequencing. Raw reads were aligned to reference probes to quantify RNA counts. Q3 normalized counts were used in downstream analyses using R version 4.1. Linear modeling was used to assess differentially expressed genes (DEGs). Hypergeometric enrichment tests were used for geneset enrichment. T-tests was used to compare gene expression between two groups. Results In total 26 ROIs (14 ductal and 15 lobular) were profiled across the three mDLC FFPE slides. Overall data quality was excellent with > 90% sequencing saturation across profiled ROIs. Principle component analysis and consensus clustering showed that lobular and ductal ROIs clustered separately indicating distinct molecular profiles. Similarly, PAM50 analysis showed that ductal and lobular ROIs within each patient tumor had distinct PAM50 subtypes. To further investigate the molecular differences between ductal vs lobular ROIs, we performed differential gene expression analysis. We identified 38 up-regulated and 78 down-regulated genes in lobular compared to ductal ROIs. To assess whether mDLC sub-components share any molecular similarities to pure counterparts i.e., ILC and NST, we compared mDLC lobular vs ductal DEGs with those from TCGA ILC vs NST comparison. SHROOM1, KLK10 and KLK11 were up-regulated while CDH1, DCD, and CPB1 were down-regulated in both mDLC lobular ROIs and ILC vs mDLC ductal ROIs and NST, respectively. Pathway analysis revealed estrogen response, adhesion, and metabolism related differences between mDLC lobular vs ductal ROIs. Furthermore, key transcription factor signatures enriched in the up-regulated genes in lobular vs ductal ROIs included ESR1, FOXA2, GATA1/2 and AR signatures while those enriched in the down-regulated genes in lobular vs ductal ROIs included RCOR1, MYC, ZBTB7A, NELFE, and SPI1 signatures. Conclusion and Future Work Using DSP, we uncovered the molecular heterogeneity of mDLC. We revealed that lobular and ductal sub-components have distinct biology with differences in transcriptional signatures and hormone signaling, adhesion and metabolism related pathways. Our pilot study is the first to shed light on this elusive mixed entity using spatial profiling. Our future work will focus on DNA sequencing of mDLC sub-components to identify sub-component specific driver mutations. Our findings will need further investigation in larger mDLC cohorts to better understand their clinical implications in terms of evolution of this disease and its prognosis. Citation Format: Osama Shiraz Shah, Azadeh Nasrazadani, Jennifer M. Atkinson, Celina Kleer, Priscilla F. McAuliffe, Rohit Bhargava, Jorge Reis-Filho, Peter C. Lucas, ADRIAN V. LEE, Steffi Oesterreich. PD4-07 Uncovering molecular heterogeneity of mixed ductal and lobular carcinoma using digital spatial profiling [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD4-07.

Abstract P3-05-25: Clinical Factors associated with Survival Outcomes in Patients with Metaplastic Breast Cancer

Abstract Background Metaplastic breast cancer (MBC) is a rare and aggressive subtype of breast cancer (BC) defined by presence of both epithelial and mesenchymal components. Most are triple negative but are often chemo-refractory and associated with poor survival outcomes compared to non-metaplastic triple negative BC. Advances in therapy have led to improvements in survival outcomes of patients (pts) with BC over the last decade. Our multicenter retrospective study aims to assess (1) progression free survival (PFS) and overall survival (OS) (2) factors predictive of survival outcomes in MBC pts Methods We performed a retrospective analysis of pts diagnosed with MBC from 1997-2021 at Mayo Clinic (Florida, Arizona and Rochester) under IRB approval. Kaplan-Meier method was used to estimate OS and PFS at 1, 3 and 5 years. Cox regression models were used to examine the association between risk factors and survival outcomes. All tests were two-sided with p value < 0.05 considered statistically significant Results We evaluated 158 pts with MBC. Median age and tumor size was 61 (range: 20-91) years and 2.8 (range: 0.5-21) cm, respectively, with 80% of pts being postmenopausal. At diagnosis, 14.6% of pts had clinical T3/T4 disease, 16.4% were clinically node-positive, and 6.3% (10 pts) had distant metastases (DM). Spindle cell histology was seen in 36 pts. Most MBC pts were triple-negative (68.3%), high grade (77.2%) and high Ki-67 (36/47; 76.5%). Of the 61 pts tested for germline mutation, 8 (13.1%) were positive, with BRCA1/2, PTEN, NBN, CHEK2, and BARD1 mutations. Most pts had lumpectomy (53.8%), followed by simple mastectomy (38.5), and modified radical mastectomy (7.7%). Majority of pts had sentinel lymph node biopsy (71.8%). Adjuvant radiation therapy was performed in 65.6% of pts. Pathologic complete response (pCR) was noted in 4/38 (10.5%) evaluable pts who received neoadjuvant chemotherapy (NACT). Residual cancer burden (RCB) scores of 2 and 3 were seen in 76.2% of evaluable pts. Median follow-up time was 2.2 years (range: 6 days-24.6 years). Overall, 1-, 3-, and 5-year OS was 93.3%, 81.7%, and 76.0%, while PFS was 80.8%, 67.9%, and 60.9%, respectively. The presence of DM at diagnosis [HR 38.55 (11.18, 132.93), p < 0.001] and spindle cell histology (SC) [HR 2.57 (1.19, 5.53), p = 0.02] predicted worse OS in multivariable analysis. Inferior PFS was predicted by DM [HR 18.84 (6.53, 54.35), p < 0.001], SC [HR 2.46 (1.25, 4.86), p = 0.009], and node-positivity at diagnosis [HR 3.65 (1.5, 8.89), p = 0.004]. The 5-year OS and PFS were 22.2% and 0% for DM pts versus 80.0% and 65.6% for non-DM pts. The 5-year OS and PFS were 71.5% and 54.7% for SC pts versus 81% and 66.6% for non-SC pts. 5-year OS and PFS for NACT pts was 67.3% and 52.6% for NACT pts versus 78.2% and 62.8% for non-NACT pts. Age at diagnosis, menopausal status, family history of BC, grade, stage, tumor size, hormone-receptor and HER2 status, and use of NACT were not found to be significantly associated with OS or PFS in multivariate analysis. Conclusion This study is one of the largest and most recent review of institutional experiences with MBC. Overall, OS at 5 years was improved compared to prior older studies of MBC but still remains very low for those with DM, representing an area of unmet clinical need. SC and DM correlated with worse outcomes for both PFS and OS. Additionally, node positivity at diagnosis was a predictor of worse PFS. In contrast, no association was seen between survival and tumor size, stage, hormone receptor-positivity, HER2 receptor-positivity. The low pCR rates following NACT in our study are consistent with reported literature. Further, use of NACT does not impact survival, suggesting pts with resectable disease should proceed with surgery first. Citation Format: Siven Chinniah, Raza Zarrar, Zhuo Li, Kostandinos Sideras, Alvaro Moreno-Aspitia, Saranya Chumsri, Rohit Rao, Sarah McLaughlin, James Jakub, Emmanuel Gabriel, Sanjay Bagaria, Laura Vallow, Santo Maimone, Pooja Advani. Clinical Factors associated with Survival Outcomes in Patients with Metaplastic Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-25.

Multimodality imaging and histopathology of metaplastic breast cancer

Metaplastic breast cancer (MBC) is a rare subtype of invasive breast cancer characterized by mixed epithelial and mesenchymal differentiation. Commonly seen subtypes include squamous cell carcinoma, spindle cell carcinoma, and metaplastic carcinoma with heterologous mesenchymal differentiation. MBC tends to have a more aggressive clinical presentation, higher metastatic potential, higher rates of local recurrence, and a worse prognosis compared with invasive breast carcinoma of no special type. Most MBCs are triple-negative breast cancers, which explains their resistance to most systemic therapies. Therefore, accurately diagnosing MBC early is crucial for deciding the treatment strategy and predicting the prognosis. In this pictorial essay, the imaging findings of MBC in different modalities and the histopathologic features of its subtypes are reviewed.

Predicting breast cancer-specific survival in metaplastic breast cancer patients using machine learning algorithms

Metaplastic breast cancer (MpBC) is a rare and aggressive subtype of breast cancer, with data emerging on prognostic factors and survival prediction. This study aimed to develop machine learning models to predict breast cancer-specific survival (BCSS) in MpBC patients, utilizing a dataset of 160 patients with clinical, pathological, and biological variables. An in-depth variable selection process was carried out using gain ratio and correlation-based methods, resulting in 10 variables for model estimation. Five models (decision tree with bagging; logistic regression; multilayer perceptron; naïve Bayes; and, random forest algorithms) were evaluated using 10-fold cross-validation. Despite the constraints posed by the absence of therapeutic information, the random forest model exhibited the highest performance in predicting BCSS, with an ROC area of 0.808. This study emphasizes the potential of machine learning algorithms in predicting prognosis for complex and heterogeneous cancer subtypes using clinical datasets, and their potential to contribute to patient management. Further research that incorporates additional variables, such as treatment response, and more advanced machine learning techniques will likely enhance the predictive power of MpBC prognostic models.

Metastatic primary breast neuroendocrine neoplasms: a case series.

Breast neuroendocrine neoplasms represent a rare subtype of breast cancer which have not been well studied or characterised, particularly in the metastatic setting. To present clinicopathological characteristics, treatment and outcomes of a series of patients with metastatic neuroendocrine carcinoma of the breast and review the current literature. We performed a retrospective review to identify and describe patients with metastatic neuroendocrine carcinoma of the breast at our centre between 2011 and 2021. Medical records, pathology and imaging results were examined to evaluate the clinical and histopathological features as well as the treatment pathways and prognosis of these patients. We present a series of seven female patients with metastatic neuroendocrine carcinoma of the breast, as defined by the World Health Organization classification, over a period of 10 years (2011-2021) from a single centre. Median age at diagnosis was 48 years (range 39-63). Six of seven tissue samples expressed synaptophysin and chromogranin and were also oestrogen and progesterone receptor positive; median Ki-67 index was 50% (range 20-90%). All seven patients had demonstrated avidity on 18 F-FDG PET imaging, and the six who underwent 68 Ga-DOTATATE PET all had significant avidity. Treatment modalities and sequencing varied, but all patients received chemotherapy during their disease course. Six patients received three or more lines of treatment. Median overall survival was 31.8 months (range 3.7-108.6). Median progression-free survival (PFS) with first-line therapy for metastatic disease was 5.8 months (range 1.8-37.8). This series shows the use of multiple modalities in treating this disease, with different sequencing in different patients. Despite multiple modalities used in the first-line setting, first-line PFS remains short. Larger series and further molecular characterisation are required to aid clinicians in managing this condition and to guide optimal treatment sequencing to improve outcomes in this rare patient group.

Invasive lobular carcinoma with extracellular mucin (ILCEM): clinicopathologic and molecular characterization of a rare entity

AbstractInvasive lobular carcinoma with extracellular mucin (ILCEM) is a rare histologic subtype of breast cancer. Little is known about the pathologic or genomic signatures that distinguish ILCEM from classic invasive lobular carcinoma (ILC) or mucinous carcinoma. We studied 17 breast cancers with lobular morphology and extracellular mucin. Thirteen tumors with sufficient tissue for DNA extraction were analyzed by a next generation sequencing (NGS) assay that interrogates 447 genes for mutations and copy number variations (CNVs). Median patient age was 66 yrs (range: 31–77 yrs). Sixteen patients presented with masses, 7 of which were >2 cm. Seven patients had lymph node metastases. The cases of ILCEM were moderately (n = 13) or poorly differentiated (n = 4), frequently exhibiting variant morphology that has not been previously described or emphasized, including grade 3 nuclei (n = 11), diffuse signet ring cells (n = 10), solid growth (n = 4), tumor necrosis (n = 3) or apocrine features (n = 2). All tumors showed absent or reduced membranous E-cadherin expression. Concurrent lobular carcinoma in situ (LCIS) was seen in 11/17 cases, 1 of which was a striking example of signet ring cell LCIS with extracellular mucin. Receptor profiles were ER+/HER2− (n = 15) and ER+/HER2+ (n = 2). With a median follow-up of 83.5 months (range: 3–171 months) in 12 patients with available information, 8 patients had recurrences resulting in 4 cancer-related deaths. The most common CNVs were 16q loss (n = 11) and 1q gain (n = 9). CDH1 gene-level alterations were detected in all but one case, including frameshift (n = 7), nonsense (n = 2), and donor splice site (n = 1) mutations and indels (n = 2). Recurrent mutations were also seen in PIK3CA (n = 3), POLQ (n = 3), TP53 (n = 3), ERBB3 (n = 3), ERBB2 (n = 2), and RUNX1 (n = 2). Genes with recurrent amplifications included GATA3 (n = 4), FOXA1 (n = 3), CCND1 (n = 2). Our data highlights ILCEM as a distinct variant of ILC that often presents with higher-grade and variant morphologic features and is associated with an aggressive clinical course. NGS data support an overall lobular-type molecular profile and reveal potentially targetable alterations in a subset of cases with recurrence.

Increased Expression of LEF1 and β-Catenin in Invasive Micropapillary Carcinoma of the Breast is Associated With Lymphovascular Invasion and Lymph Node Metastasis.

Invasive micropapillary breast carcinoma (IMPC) is a rare breast cancer subtype characterized by small tumor cell clusters with loss of stromal attachment, an inside-out growth appearance, and lymphotropism. IMPC is associated with high incidence of lymphovascular invasion (LVI) and lymph node metastasis. Activated Wnt signaling has been implicated in the metastasis of other aggressive breast tumors, including triple-negative and basal-like carcinomas. In this study, we tested whether activated Wnt signaling could be detected in IMPC. Upon ligand binding, the central mediator of the Wnt pathway, β-catenin, accumulates in the cytosol and translocates to the nucleus where it forms a complex with lymphoid enhancer-binding factor 1 (LEF1) to regulate transcription. We performed immunostaining for β-catenin and LEF1 on a well-annotated cohort of 40 breast tumors and nodal metastases displaying micropapillary histopathology. Strong nuclear accumulation of β-catenin was not observed, however a dim cytosolic and/or nuclear accumulation of β-catenin was sometimes seen in IMPC and this expression pattern was significantly associated with nodal metastasis. β-catenin expression correlated with the upregulation of LEF1 in IMPC. LEF1 expression was detected in 26 of 40 (65%) cases and was specifically enriched at the invasive front of the tumor and in tumor clusters undergoing LVI. Detection of LEF1 expression in the primary tumor was associated with an increased rate of LVI, lymph node metastasis, and disease relapse. LEF1 and β-catenin expression levels were significantly higher in metastases compared with primary tumors. In summary, this study demonstrates an association between the upregulation of β-catenin/LEF1 and the metastasis of IMPC.

Solid-basaloid variant of adenoid cystic carcinoma of the breast with near complete response to neoadjuvant chemotherapy

Breast adenoid cystic carcinoma (AdCC) is a rare subtype of triple negative breast cancer. Two morphologic variants are described, namely classic AdCC (C-AdCC) and solid basaloid (SB-AdCC). Recent studies have shown that the SB-AdCC variant has significantly worse prognosis than C-AdCC. Due to the rarity of SB-AdCC, no standard recommendations are available for its management. Data on the use and benefit of chemotherapy in patients with SB-AdCC are sparse and the response to neoadjuvant chemotherapy has not been reported. We present the clinical and pathologic findings of a patient with SB-AdCC treated with neoadjuvant chemotherapy who achieved a remarkable pathologic response.

Long-term Oncologic Outcomes in Patients with Inflammatory Breast Cancer with Supraclavicular Nodal Involvement.

Inflammatory breast cancer (IBC) is a rare and aggressive subtype of breast cancer characterized by rapid progression and early metastasis, often with advanced nodal locations, including the supraclavicular (SCV) nodal basin. Previously considered M1 disease, ipsilateral clinical supraclavicular node involvement (N3c) disease is now considered locally advanced disease and warrants treatment with intent to cure. The objective of this study was to evaluate the long-term outcomes of patients with IBC and N3c disease. This study was conducted using a prospectively collected database of all patients with IBC treated at a dedicated cancer center from 2007 to 2019. Surgical patients with SCV nodal involvement and complete follow-up were identified. Our primary outcome was 5-year overall survival (OS). Multivariate Cox proportional hazards models were used to determine predictors for survival. Event-free survival (EFS) and OS were calculated using the Kaplan-Meier method. There were 70 patients who met inclusion criteria. All patients underwent comprehensive trimodality therapy. The majority of patients had complete (66.2%) radiologic response in the SCV nodal basins following neoadjuvant therapy. Six patients (8.6%) had a locoregional recurrence, with two (2.9%) occurring in the supraclavicular fossa. The 5-year OS was 60.2% [95% confidence interval (CI) 47.7-72.7%]. Increasing age (hazard ratio 2.7; p = 0.03) and triple-negative subtype (hazard ratio 4.9; p = 0.03) were associated with poor OS. The 5-year EFS was 56.1% (95% CI 40.9-68.8%). The presence of more than ten positive axillary nodes on final surgical pathology (hazard ratio 5.5; p = 0.01) predicted poor EFS. With comprehensive trimodality therapy and multidisciplinary team approach, patients with IBC with supraclavicular nodal involvement experience excellent locoregional control and favorable survival.

Effect of postoperative radiotherapy in women with localized pure mucinous breast cancer after lumpectomy: a population-based study

PurposePure mucinous breast cancer is a rare subtype of invasive breast cancer with favorable prognosis, in which the effect of postoperative radiotherapy remains unclear. We aimed to investigate the prognostic value of postoperative radiotherapy in women with localized pure mucinous breast cancer after lumpectomy.MethodsWe conducted a retrospective cohort study to compare the effectiveness of postoperative radiotherapy (RT) and omitting postoperative radiotherapy (non-RT) in patients with first primary T1-2N0M0 (T ≤ 3 cm) pure mucinous breast cancer who underwent lumpectomy between 1998 and 2015 using the Surveillance, Epidemiology, and End Results (SEER) database. Breast cancer-specific survival (BCSS) was compared between RT and non-RT groups using Kaplan–Meier method and Cox proportional hazards regression model. Propensity score matching (PSM) was carried out to balance cohort baselines. In addition, an exploratory analysis was performed to verify the effectiveness of RT in subgroup patients.ResultsOf 7832 eligible patients, 5352 (68.3%) underwent lumpectomy with postoperative RT, 2480 (31.7%) received lumpectomy without postoperative RT. The median follow-up duration was 92 months. The median age was 66 years in the RT group and 76 years in the non-RT group.The 15-year BCSS was 94.39% (95% CI, 93.08% to 95.35%) in the RT group versus 91.45%(95% CI, 88.93% to 93.42%) in the non-RT group (P < 0.001). The adjusted hazard ratio for BCSS was 0.64 (95% CI, 0.49 to 0.83; P = 0.001) for RT group versus non-RT group. After propensity score matching, similar results were yielded. Adjuvant RT reduced the 15-year risk of breast cancer death from 7.92% to 6.15% (P = 0.039). The adjusted hazard ratio for BCSS were 0.66 (95%CI, 0.47 to 0.92; P = 0.014) for RT group versus non-RT group. The benefit of RT was well consistent across subgroup patients.ConclusionAmong women with T1-2N0M0 (tumor size ≤ 3 cm) pure mucinous breast cancer, the addition of RT after lumpectomy was significantly associated with a reduced incidence of breast cancer death compared with non-RT, and the magnitude of benefit may be modest. This suggests that postoperative RT is recommended in the treatment of localized pure mucinous breast cancer.

Triple-Negative Apocrine Breast Carcinoma Has Better Prognosis despite Poor Response to Neoadjuvant Chemotherapy.

Apocrine carcinoma is a rare subtype of invasive ductal breast cancer that shows apocrine differentiation and largely triple-negative immunohistology. Triple-negative breast cancers are known to have more aggressive clinical courses. However, unlike most other subtypes, it is reported that triple-negative apocrine carcinoma (TNAC) has a better prognosis. Due to the scarcity of reported studies, our knowledge regarding its clinical behavior, prognosis and response to therapy is very limited. In this study, we retrospectively retrieved 41 triple-negative apocrine carcinoma cases from our breast cancer database, with an average follow-up of 32.8 months. It was found that TNAC had a poorer response to neoadjuvant therapy but a better prognosis than other nonapocrine types of triple-negative breast cancer. Meanwhile, TNAC has a low proliferative nature, as indicated by its low Ki-67 index. An updated analysis of the Surveillance, Epidemiology, and End Results database showed that chemotherapy did not improve breast-cancer-specific survival in TNAC patients. Our results suggest that TNAC is a special subtype of triple-negative breast cancer with a better short-term prognosis despite poor response to neoadjuvant chemotherapy.

Integrative proteomic and phosphoproteomic profiling of invasive micropapillary breast carcinoma

Invasive micropapillary carcinoma (IMPC) is a rare subtype of breast cancer with an aggressive phenotype and a poor prognosis. The mechanism of tumorigenesis of IMPC in breast remains unknown. Integrative analysis of the proteome and phosphoproteome may shed light on the mechanism of IMPC carcinogenesis. In our study, primary IMPC and paired normal breast tissue were collected from six patients and subjected to label free LC-MS/MS for quantitative proteomic and phosphoproteomic analysis. Kinase-substrate enrichment analysis (KSEA) was conducted to identify hyperactivated/inhibited kinases. Proteomic and phosphoproteomic data was combined to investigate cancer specific activated pathways. A total of 1331 differentially expressed proteins were identified. The proteomic analysis revealed a dysregulation of protein homeostasis in IMPC. Phosphoproteomic profiling identified 856 differentially phosphorylated phosphosites in 655 proteins. KSEA found that cyclin dependent kinases (CDKs) and the p90 ribosomal S6 kinases (RSKs) were highly activated, while protein kinase A (PKA) and protein kinase C (PKC) families were significantly inhibited in IMPC. Finally, cancer-specific activation of mTORC1/S6K2 signaling was also discerned in our integrative analysis. Overall, this study provides a comprehensive landscape of the proteome and phosphoproteome of IMPC, which will contribute to a further understanding of IMPC tumorigenesis and treatment. SignificanceThis is the first study to provide the integrative proteomic and phosphoproteomic landscape of IMPC. Our study demonstrated that protein homeostasis dysregulation is one of the most prominent characteristics in IMPC. We also identifying several kinases which might have the potential to be novel targets in clinical practice. Cancer-specific activation of mTORC1/S6K2 signaling was discerned by integrative proteomic and phosphoproteomic analysis. The present study might contribute to a further understanding of IMPC tumorigenesis and treatment.

Neuroendocrine carcinoma of the breast: a case report

Neuroendocrine breast carcinomas represent a rare subtype of breast cancer. Their definition, prevalence and prognosis remain controversial in the literature. Regarding the presentation, there are no differences from other breast carcinomas and clinical syndromes related to hormone production are extremely rare. Refinement of the classification of neuroendocrine neoplasms of the breast is needed in order to improve the reproducibility of their diagnostic criteria and to define their clinical significance. This article presents the case of a 44-year-old female patient diagnosed with invasive breast carcinoma with neuroendocrine features, according to the 2012 World Health Organization (WHO) definition, with focus on presentation, clinical manifestations, diagnostic approach and differential diagnosis.

Metaplastic carcinoma breast: Three year histopathological analysis at a tertiary care centre of Kashmir

Background: Metaplastic breast carcinomas (MBCs) comprise a rare but aggressive subtype of breast cancer and represent less than 5% of invasive breast carcinomas. Histologically, metaplastic breast carcinoma is characterized by the presence of divergent cellular differentiation and heterologous elements, including squamous, spindled, sarcomatoid /pleomorphic, chondroid, and osseous differentiation. Material and Methods: Histopathologic characteristics of 11 cases of metaplastic carcinoma of breast encountered over a period of three years from May 2016 to May 2019 in our institute. Results: We encountered 11 cases of metaplastic breast cancers out of 226 primary breast malignancies. Two were breast conservation surgeries and the rest were modified radical mastectomies. The histopathological patterns encountered included squamous, chondroid, sarcomatoid and mixed histologic subtypes. Median tumor size was 3.5 cm, majority were triple-negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. All except two patients had lymph nodal metastasis. Conclusion: Metaplastic breast carcinoma is a rare type of breast cancer associated with a poor prognosis. Most patients in this series had high-grade, triple-negative tumors and were treated with optimal therapy.

S3168 Metastatic Breast Cancer to a J-Shaped Muscular Bag – The Stomach

Introduction: Female breast cancer was the leading cause of global cancer incidence in 2020, with an estimated 2.3 million new cases, representing 11.7% of all cancer cases. The most common primary target sites of breast cancer metastasis are bone, lung, liver, and brain. The stomach is an infrequent site of breast cancer metastasis, accounting for an incidence ranging from 0.3% in retrospective studies to 8-18% in autopsy series. Needless to say, metastasis to the stomach from any primary tumor is itself atypical, with an incidence of 0.2-1.7%. We present a case of breast cancer metastasis to the stomach from a rare histological subtype of breast cancer- glycogen-rich, clear cell breast carcinoma. Case Description/Methods: 75- year-old female with clear cell glycogen rich invasive carcinoma, stage IIIB of the right breast presented to the emergency department (ED) complaining of fatigue and weakness for two days. Vital signs were normal. Physical examination revealed ataxic gait and right-sided hemiparesis. Labs showed a hemoglobin of 7.5 g/dl (baseline 9.8 g/dl) and hematocrit 23.5% (baseline 30%). The following day her hemoglobin asymptomatically dropped to 6.8 g/dl, and a repeat reading showed a further decline to 5.8 g/dl. Two units of packed red blood cells (PRBC) were transfused, which increased her hemoglobin to 7.8 g/dl. Fecal Occult Blood Test (FOBT) was positive, and gastroenterology was consulted to investigate further. Computerized Tomography (CT) of the abdomen showed a 4.4 cm intraperitoneal mass in the left mid-abdomen highly suggestive of metastasis. Esophagogastroduodenoscopy (EGD) revealed several gastric ulcers on the greater aspect of the stomach's body located on the mucosal mound or raised mucosa (Figure 1). Given the undermining margins and the ulcer's location, there was increased suspicion for malignancy and she was diagnosed with metastatic poorly differentiated gastric adenocarcinoma. Due to the patient's low-performance status, hospice/palliative care was pursued. Discussion: The exact mechanism of gastric metastasis of breast cancer is still unclear. Gastric metastasis can have a negative impact on survival and must be investigated in patients with breast cancer who present with non-specific gastrointestinal symptoms. There should be a very high index of suspicion for a prompt diagnosis. In patients with a history of breast cancer, gastric endoscopy should be offered in cases of GI symptoms, even when the symptoms are vague.Figure 1.: Gastric perforation secondary to malignant gastric outlet obstruction.

In-depth characterization of a new patient-derived xenograft model for metaplastic breast carcinoma to identify viable biologic targets and patterns of matrix evolution within rare tumor types

Metaplastic breast carcinoma (MBC) is a rare breast cancer subtype with rapid growth, high rates of metastasis, recurrence and drug resistance, and diverse molecular and histological heterogeneity. Patient-derived xenografts (PDXs) provide a translational tool and physiologically relevant system to evaluate tumor biology of rare subtypes. Here, we provide an in-depth comprehensive characterization of a new PDX model for MBC, TU-BcX-4IC. TU-BcX-4IC is a clinically aggressive tumor exhibiting rapid growth in vivo, spontaneous metastases, and elevated levels of cell-free DNA and circulating tumor cell DNA. Relative chemosensitivity of primary cells derived from TU-BcX-4IC was performed using the National Cancer Institute (NCI) oncology drug set, crystal violet staining, and cytotoxic live/dead immunofluorescence stains in adherent and organoid culture conditions. We employed novel spheroid/organoid incubation methods (Pu·MA system) to demonstrate that TU-BcX-4IC is resistant to paclitaxel. An innovative physiologically relevant system using human adipose tissue was used to evaluate presence of cancer stem cell-like populations ex vivo. Tissue decellularization, cryogenic-scanning electron microscopy imaging and rheometry revealed consistent matrix architecture and stiffness were consistent despite serial transplantation. Matrix-associated gene pathways were essentially unchanged with serial passages, as determined by qPCR and RNA sequencing, suggesting utility of decellularized PDXs for in vitro screens. We determined type V collagen to be present throughout all serial passage of TU-BcX-4IC tumor, suggesting it is required for tumor maintenance and is a potential viable target for MBC. In this study we introduce an innovative and translational model system to study cell–matrix interactions in rare cancer types using higher passage PDX tissue.

Hormone Receptor Status May Impact the Survival Benefit Between Medullary Breast Carcinoma and Atypical Medullary Carcinoma of the Breast: A Population-Based Study.

BackgroundA rare subtype of breast cancer, atypical medullary carcinoma of the breast (AMCB), shows a highly adverse prognosis compared to medullary carcinoma of the breast (MBC). The current study aimed to establish a correlated nomogram for the identification of the prognostic factors of AMCB and MBC.MethodsKaplan–Meier and Cox regression analyses were applied to data acquired from the Surveillance, Epidemiology and End Results (SEER) database for 2004 to 2013 to analyse tumour characteristics and overall survival. Propensity score matching (PSM) analysis was performed to determine the overall survival (OS) among those with AMCB and MBC. A predictive nomogram was created, and the concordance index (C-index) was used to predict accuracy and discriminative ability.ResultsA total of 2,001 patients from the SEER database were diagnosed with MBC between 2004 and 2013, including 147 patients diagnosed with AMCB. The number of diagnoses gradually increased in both groups. Cox analysis of multivariate and Kaplan–Meier analysis showed that older age (HR = 3.005, 95% CI 1.906–4.739) and later stage were significantly associated with poor prognosis, while cancer-directed surgery was an independent protective factor (HR = 0.252, 95% CI 0.086–0.740). In the HR-negative stratification analysis, older age (HR = 2.476, 95% CI 1.398–4.385), later stage and histological type (HR=0.381, 95% CI 0.198-0.734) were found to be independent prognostic factors for low standard survival. The log-rank analysis demonstrated significantly worse prognostic factors for patients with AMCB than for those with MBC (P = 0.004). A nomogram (C-index for survival = 0.75; 95% CI 0.69–0.81) was established from four independent prognostic factors after complete identification.ConclusionsMBC is rare, and cancer-directed surgery, older age, and later stage are independently linked with prognosis. In the HR negative population, AMCB patients show a worse survival gain than those with MBC.

Neuroendocrine Breast Cancer. Clinical Observation. Personalized Approach

Introduction. Neuroendocrine breast tumors represent a rare subtype of breast cancer, accounting for less than 1 % of all neuroendocrine neoplasms. Starting from their pathology definition, and going through their prevalence, prognosis and treatment, our knowledge is still really uncertain.Materials and methods. The article presents a rare clinical observation of a neuroendocrine breast tumor. A breast fibroadenoma was diagnosed at the initial diagnosis stage in a private clinic; after a surgical treatment and further morphological study, it was estimated: a diagnosis of Cancer in situ of the left breast T1N0M0, stage I. Next, 3D-conformal remote radiation therapy was performed on the area of the left breast.Results and discussion. After conducting positron emission tomography, multiple metastases were detected in the lymph nodes, bones, and liver. Additionally, micropreparations were consulted at the Federal Reference Center in St. Petersburg and at an independent third-party molecular biological laboratory in Germany (Munich). Given all the instrumental, molecular biological, histological and immunohistochemical studies of the patient, an individual regimen of drug therapy was selected.Conclusion. After 18 months of personalized drug therapy, we observed a positive trend and a significant decrease in metabolic activity according to positron emission tomography.

Progress for Immunotherapy in Inflammatory Breast Cancer and Emerging Barriers to Therapeutic Efficacy

Simple SummaryDespite recent advances in the treatment of other breast cancer subtypes, inflammatory breast cancer (IBC) remains a significant clinical challenge, with an overall 5-year survival rate of 39%. Though immunotherapy has shown remarkable efficacy in other difficult-to-treat cancers, such approaches have yet to show substantial therapeutic efficacy in IBC. Here, we summarize the known immune composition of IBC tumors, as well as past and present efforts to advance immunotherapy in the treatment of IBC.Inflammatory breast cancer (IBC) is a rare and aggressive subtype of breast cancer that carries a particularly poor prognosis. Despite the efficacy of immunotherapy in other difficult to treat forms of breast cancer, progress for immunotherapy in IBC has been difficult. Though immunotherapy has been under clinical investigation in IBC since the 1970s, few approaches have shown significant therapeutic efficacy, and no immunotherapy regimens are currently used in the treatment of IBC. Here, we provide a comprehensive summary of what is known about the immune composition of IBC tumors, clinical and basic science evidence describing the role for immune checkpoints such as PD-L1 in IBC pathobiology, as well as past and present attempts to advance ICIs in the treatment of IBC.

Nomogram for predicting preoperative regional lymph nodes metastasis in patients with metaplastic breast cancer: a SEER population-based study

BackgroundMetaplastic breast cancer (MBC) is a rare subtype of breast cancer, and generally associated with poor outcomes. Lymph nodes metastasis (LNM) is confirmed as a critical independent prognostic factor and determine the optimal treatment strategies in MBC patients. We aimed to develop and validate a nomogram to predict the possibility of preoperative regional LNM in MBC patients.MethodsMBC patients diagnosed between 1990 and 2016 in the Surveillance, Epidemiology, and End Results (SEER) database were included and stochastically divided into a training set and validation set at a ratio of 7:3. The risk variables of regional LNM in the training set were determined by univariate and multivariate logistic regression analyses. And then we integrated those risk factors to construct the nomogram. The prediction nomogram was further verified in the verification set. The discrimination, calibration and clinical utility of the nomogram were evaluated by the area under the receiver operating characteristic (ROC) curve (AUC), calibration plots and decision curve analysis (DCA), respectively.ResultsA total of 2205 female MBC patients were included in the study. Among the 2205 patients, 24.8% (546/2205) had positive regional lymph nodes. The nomogram for predicting the risk of regional LNM contained predictors of grade, estrogen receptor (ER) status and tumor size, with AUC of 0.683 (95% confidence interval (CI): 0.653–0.713) and 0.667 (95% CI: 0.621–0.712) in the training and validation sets, respectively. Calibration plots showed perfect agreement between actual and predicted regional LNM risks. At the same time, DCA of the nomogram demonstrated good clinical utilities.ConclusionsThe nomogram established in this study showed excellent prediction ability, and could be used to preoperatively estimate the regional LNM risk in MBC.