Frequency of Clinically Significant Findings in the Surgical Pathology Specimen Following Laparoscopic Sleeve Gastrectomy and Concordance with Preoperative Endoscopy: Insights from a Large Single-Center Experience

INTRODUCTION

Endoscopy prior to bariatric surgery is not always performed, and in sleeve gastrectomy (SG), the surgical specimen is not always sent for pathological examination. There is limited data on the frequency of clinically significant findings in SG specimens or correlation with preoperative endoscopy.

METHODS

We reviewed 426 consecutive SG patients to determine the concordance of preoperative endoscopy findings in patients with clinically significant postoperative pathology.

RESULTS

Preoperative endoscopy was performed on 397 patients (93.2%). Three hundred seventy-three patients had preoperative endoscopy and surgical pathology results available. Then, 20/373 (5.4%) patients had potentially significant postoperative pathology, including intestinal metaplasia, autoimmune metaplastic atrophic gastritis (AMAG), gastrointestinal stromal tumors, and/or gastric cancer. The overall incidence of AMAG in the entire cohort was 2.3%. Preoperative gastric biopsies (to include gastric body) identified AMAG in nearly 1/2 of patients. Patients with clinically significant postoperative pathology results had a median [interquartile range] of 3 [3-5] tissue blocks examined as compared to 3 [1-3] for the remainder of the cohort (p < 0.001).

CONCLUSION

This is one of the largest studies describing clinically significant postoperative pathology after SG. AMAG, in particular, is of particular importance as it is associated with a 3-fivefold increase in risk for gastric cancer. The incidence of significant postoperative pathology in this population is small but potentially clinically significant and requires validation in larger studies. We recommend wider sampling in preoperative endoscopy (body and antrum), especially in patients being planned for gastric bypass, consideration for routine pathological examination of SG surgical specimens, with careful gross examination and targeted sampling.

Metaplastic Breast Cancer: Current Understanding and Future Directions

Metaplastic breast cancers (MBC) encompass a group of highly heterogeneous tumors which share the ability to differentiate into squamous, mesenchymal or neuroectodermal components. While often termed rare breast tumors, given the relatively high prevalence of breast cancer, they are seen with some frequency. Depending upon the definition applied, MBC represents 0.2% to 1% of breast cancers diagnosed in the United States. Less is known about the epidemiology of MBC globally, though a growing number of reports are providing information on this. These tumors are often more advanced at presentation relative to breast cancer broadly. While more indolent subtypes exist, the majority of MBC subtypes are associated with inferior survival. MBC is most commonly of triple-negative phenotype. In less common hormone receptor positive MBCs, hormone receptor status appears not to be prognostic. In contrast, relatively rare HER2-positive MBCs are associated with superior outcomes. Multiple potentially targetable molecular features are overrepresented in MBC including DNA repair deficiency signatures and PIK3/AKT/mTOR and WNT pathways alterations. Data on the prevalence of targets for novel antibody-drug conjugates is also emerging. While chemotherapy appears to be less active in MBC than in other breast cancer subtypes, efficacy is seen in some MBCs. Disease-specific trials, as well as reports of exceptional responses, may provide clues for novel approaches to this often hard-to-treat breast cancer. Strategies which harness newer research tools, such as large data and artificial intelligence hold the promise of overcoming historic barriers to the study of uncommon tumors and could markedly advance disease-specific understanding in MBC.

The conundrum of metaplastic breast cancer: a single Egyptian institution retrospective 10-year experience (2011-2020)

BACKGROUND

Metaplastic breast cancer (MetBC) still represents a conundrum owing to its peculiar histogenesis and molecular drivers that render it extremely resistant to standard chemotherapy with ultimate dismal survival.

AIM

Describe the Egyptian National Cancer Institute's (NCI-E) experience with MetBC regarding its clinicopathologic features, treatment, and survival outcomes.

PATIENTS AND METHODS

Between 2011 and 2020, all MetBC patients presented to NCI-E were retrospectively evaluated. Original clinicopathologic data, therapeutic modalities, pathologic response to neoadjuvant chemotherapy (NACT), recurrence, and date of last follow-up/death were obtained from archived charts.

RESULTS

A cohort of 135 females, the median age was 52 years, and median follow-up period was 40 months (range: 2.6-130.8). Two-thirds were triple negative (TN). Squamous carcinoma was prevalent in 74.8% followed by carcinoma with osseous/chondroid differentiation, spindle cell, and low-grade adenosquamous carcinoma encountered in 13.3, 7.4, and 4.5%, respectively. Modified radical mastectomy was done in 59.3%, and positive nodes (pN+) were depicted in 37.7%. Median Ki-67 was 45% (range: 10-88); grade III and lymphovascular invasion (LVI) were observed in 83.7 and 43.7%, respectively. Stage II was the most common (49%), whereas initial stage IV was encountered in 8.1%. Anthracyclines/taxane combinations were rampant in adjuvant/neoadjuvant settings. The latter was employed in 41 patients, with only 3 cases (7.3%) achieving pathologic complete response (pCR), while moderate/significant residual tumor burden was found in 83%. The 5-year DFS and OS were 56.4 and 57.6%, respectively. Spindle cell carcinoma showed the worst survival parameters in univariate analysis. On the multivariate level, higher tumor stage (pT3 & 4), Ki-67 ≥ 45%, and TN subtype were independent variables for worse DFS and OS; age ≥ 52 years and the presence of LVI were independent features for worse DFS, whereas pN+ was an independent parameter for worse OS.

CONCLUSIONS

This study further solidifies the dreadful response of MetBC to conventional chemotherapy regimens employed in common non-metaplastic pathologies. A radical shift in treatment standards tailored to combat the molecular landscape of this distinctive tumor is urgently needed. Immunotherapy and molecularly targeted agents demonstrated promising results in phase I and II trials with hopeful sooner implementation in phase III studies.

Life on bottles: Colonisation of macroplastics by freshwater biota

While rivers are known to be the main vectors of plastics to the sea, it seems surprising that studies on interactions (e.g. colonisation/entrapment and drift) between macroplastics and biota continue to remain largely neglected, notwithstanding they represent unexpected threats to freshwater biota and riverine habitats. To fill these gaps, here we focused on the colonisation of plastic bottles by freshwater biota. To do so, we collected 100 plastic bottles from the River Tiber in summer 2021. Overall, 95 bottles were colonised externally and 23 internally. Specifically, biota mainly occurred within and outside the bottles rather than plastic pieces and organic debris. Moreover, while bottles were externally covered mainly by vegetal organisms (i.e. macrophytes), they internally entrapped more animal organisms (i.e. invertebrates). The taxa most occurring within and outside the bottles belonged to pool and low water quality-associated taxa (e.g. Lemna sp., Gastropoda, and Diptera). In addition to biota and organic debris, plastic particles also occurred on bottles reporting the first observation of 'metaplastics' (i.e. plastics encrusted on bottles). Furthermore, we observed a significant positive correlation between the colonising taxa abundance and the bottle degree degradation. In this regard, we discussed how bottle buoyancy may change due to the organic matter on the bottle, affecting bottle sinking and transport along rivers. Our findings might be crucial for understanding the underrepresented topic of riverine plastics and their colonisation by biota, given that these plastics may act as vectors and cause biogeographical, environmental, and conservation issues to freshwater habitats.

Disease Behavior and Treatment Response of Special Histological Types of Triple-Negative Breast Cancer

BACKGROUND

Special histological types (SHT) of triple-negative breast cancer (TNBC) are a heterogeneous group of rare poorly understood diseases. We aimed to evaluate the clinical features, treatment, and outcomes of patients with SHT of TNBC.

METHODS

We evaluated patients with a SHT of TNBC treated in a cancer center between 2009 and 2020. The endpoints were characterization of clinical and pathological features, pathologic complete response (PCR) rate after neoadjuvant chemotherapy, disease-free survival (DFS), progression-free survival, and overall survival (OS).

RESULTS

The 132 patients included had the following histologies: metaplastic (n=71), medullary pattern (n=14), lobular (n=12), adenoid cystic (n=12), apocrine (n=10), and others (n=13). Metaplastic, lobular, and medullary pattern tumors had higher grade (66.6-85.7% grade 3); adenoid cystic and apocrine had mainly grade 1-2 (70-83.3%). Metaplastic and lobular carcinomas had higher disease stages (47.8% and 58.2% stages III-IV). PCR rates were 10.3% for metaplastic and 33.3% for lobular carcinomas, with 5-year DFS rates of 56% and 51.4%. Medullary pattern carcinomas had a great response to treatment, with PCR rate of 100%, and 5-year DFS rate of 92.8%. Apocrine carcinomas also had favorable prognosis, with no recurrence after early disease treatment, and 5-year DFS rate of 83.3%. Adenoid cystic carcinomas had intermediate prognosis, with 5-year DFS rate of 66.6%.

CONCLUSION

SHT of TNBC encompasses heterogeneous malignancies with distinct behaviors. Lobular and metaplastic carcinomas showed high aggressiveness and poor treatment response, while medullary pattern and apocrine carcinomas had favorable outcomes. Treatment strategies focus on molecular features of each of these diseases are warranted.

AGR2-Dependent Nuclear Import of RNA Polymerase II Constitutes a Specific Target of Pancreatic Ductal Adenocarcinoma in the Context of Wild-Type p53

BACKGROUND & AIMS

Promoted by pancreatitis, oncogenic KrasG12D triggers acinar cells' neoplastic transformation through acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia. Anterior gradient 2 (Agr2), a known inhibitor of p53, is detected at early stage of pancreatic ductal adenocarcinoma (PDAC) development. RNA polymerase II (RNAPII) is a key nuclear enzyme; regulation of its nuclear localization in mammalian cells represents a potential therapeutic target.

METHODS

A mouse model of inflammation-accelerated KrasG12D-driven ADM and pancreatic intraepithelial neoplasia development was used. Pancreas-specific Agr2 ablation was performed to access its role in pancreatic carcinogenesis. Hydrophobic hexapeptides loaded in liposomes were developed to disrupt Agr2-RNAPII complex.

RESULTS

We found that Agr2 is up-regulated in ADM-to-pancreatic intraepithelial neoplasia transition in inflammation and KrasG12D-driven early pancreatic carcinogenesis. Genetic ablation of Agr2 specifically blocks this metaplastic-to-neoplastic process. Mechanistically, Agr2 directs the nuclear import of RNAPII via its C-terminal nuclear localization signal, undermining the ATR-dependent p53 activation in ADM lesions. Because Agr2 binds to the largest subunit of RNAPII in a peptide motif-dependent manner, we developed a hexapeptide to interfere with the nuclear import of RNAPII by competitively disrupting the Agr2-RNAPII complex. This novel hexapeptide leads to dysfunction of RNAPII with concomitant activation of DNA damage response in early neoplastic lesions; hence, it dramatically compromises PDAC initiation in vivo. Moreover, the hexapeptide sensitizes PDAC cells and patient-derived organoids harboring wild-type p53 to RNAPII inhibitors and first-line chemotherapeutic agents in vivo. Of note, this therapeutic effect is efficient across various cancer types.

CONCLUSIONS

Agr2 is identified as a novel adaptor protein for nuclear import of RNAPII in mammalian cells. Also, we provide genetic evidence defining Agr2-dependent nuclear import of RNAPII as a pharmaceutically accessible target for prevention and treatment in PDAC in the context of wild-type p53.

Triple-negative metaplastic breast cancer: treatment and prognosis by type of surgery

BACKGROUND

The role of surgery type in the prognosis of triple-negative metaplastic breast cancer (TN-MBC) patients remains controversial. Our study was designed to assess the role of surgery type in patient outcomes.

MATERIALS AND METHODS

Data from the Surveillance, Epidemiology, and End Results database were extracted to analyze patients with TN-MBC between 2010 and 2016. Kaplan-Meier analyses and multivariate Cox proportional models were used to estimate the prognoses.

RESULTS

We included 1,146 patients with a median follow-up time of 26 months (range 1-83 months). 470 (41.0%), 369 (32.2%), 244 (21.3%), and 63 (5.5%) patients underwent breast-conserving surgery (BCS), total mastectomy (TM), radical mastectomy, or no surgery. With the multivariate Cox analysis, the prognosis was related to age, TNM stage, and surgery type. With the Kaplan-Meier analysis, the more radical the operation, the worse the prognosis for the patients in the entire cohort. Within stage I-III disease, the best prognoses were observed in the patients undergoing BCS, followed by TM and radical mastectomy. The adjusted survival analysis showed that the prognoses of the patients undergoing BCS were better than the prognoses of the patients undergoing TM. Within stage IV disease, the patients who underwent an operation had a better prognosis regardless of the mode.

CONCLUSION

Patients undergoing BCS had the best prognoses among the patients with early and locally advanced TN-MBC. This improves our understanding of the clinicopathological and prognostic features of this rare entity but also provides more convincing therapeutic guidelines for TN-MBC.

Presentation and survival by hormonal receptor status in metaplastic breast cancer: A propensity score-matched analysis

Background

Metaplastic breast cancer (MBC) is a rare and aggressive form of breast cancer. The effectiveness of chemotherapy (CT) for MBC remains controversial. The present study aimed to evaluate the efficacy of CT combined hormone receptor (HR) status on MBC patients with high risk (T1-4N2-3M0 and T4N0-1M0) by propensity-score matching (PSM).

Methods

A retrospective study was performed to analyze MBC from the SEER database. Breast cancer-specific survival (BCSS) was analyzed using the Kaplan–Meier curve. Cox proportional hazard models were used to assess BCSS. PSM was used to make 1:1 case-control matching.

Results

This study identified 3116 patients. The median follow-up time was 44 months (range, 1–321 months). About 62.5 % of patients received CT. 23.0 % of patients were HR-positive. Recurrence risk had a significant difference between the HR-negative and HR-positive groups. In the multivariable Cox regression model, CT had no benefit for MBC patients. HR status was not associated with a better prognosis. In subgroup analysis, the Kaplan–Meier analysis showed that HR-negative MBC with intermediate-risk benefited from CT. For HR-positive MBC, patients with intermediate and high risk also benefited from CT. After PSM, neither CT nor HR status was not related to better BCSS. Moreover, the use of CT could only improve the survival of HR-positive MBC patients with high risk.

Conclusion

PSM analysis showed that HR status was not associated with a better prognosis. CT was not a significant prognostic factor for prognosis. However, HR-positive MBC patients with high risk might benefit from CT.

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Metaplastic breast cancer (MBC) is a rare and aggressive form of breast cancer.

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Hormone receptor (HR) status was not associated with a better prognosis.

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Chemotherapy (CT) was not a significant prognostic factor for prognosis.

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HR-positive MBC patients with high risk might benefit from CT.

Intraosseous metaplastic meningioma: A case report

Metaplastic meningioma is a rare World Health Organization Grade I meningioma subtype, accounting for 0.2%-1.6% of all meningiomas. Primary extradural meningiomas represent less than 2% of all meningiomas, with intraosseous meningioma as a subtype of primary extradural meningiomas. Herein, we report the case of a 65-year-old male presenting with headache. His computed tomography scans showed an osteolytic left parietal bone mass, and magnetic resonance imaging revealed hyperintense dots in the mass on T1-weighted images. The mass was then resected and diagnosed on histopathological examination as an intraosseous metaplastic meningioma.

Mullerianosis of the urinary bladder; A case report

INTRODUCTION

Mullerianosis is a sporadic condition of the urinary bladder. The study aims to present a case of mullerianosis with a brief literature review.

CASE PRESENTATION

A 52-year-old lady presented with hematuria for one-year duration. A general urine examination showed microscopic hematuria. Abdominal and transvaginal ultrasonography revealed a soft tissue mass (13 * 10 mm) within the base of the urinary bladder. Cystoscopy showed 1.0 * 1.3 cm benign-looking mass bulging into the posterior bladder wall covered by a normal bladder mucosa. Transurethral resection was done. The histopathological examination was consistent with mullerianosis.

DISCUSSION

Two hypotheses have been proposed; the first one (implantation theory) believing that at the time of pelvic surgery and caesarian delivery Mullerian tissues become implanted inside the bladder. The second theory (metaplastic theory) holds the probability of differentiation of Mullerian epithelium to endometrial, endocervical, and tubal components and proliferation in the bladder.

CONCLUSION

mullerianosis is a very infrequent entity that mainly affects the urinary bladder and is mainly reported in females during the reproductive period, medical and surgical treatment are both regarded as the management options.

Does treatment sequence affect outcomes in patients with metaplastic breast cancer?

INTRODUCTION

We compared characteristics and outcomes by treatment sequence among patients with metaplastic breast cancer (MBC), an aggressive subtype.

METHODS

Women ≥18 years old with newly diagnosed Stage I-III MBC from 2003 to 2018 who received any treatment in our health system were identified. Unadjusted overall survival (OS) was estimated with the Kaplan-Meier method; the log-rank test was used to compare survival differences between recipients of neoadjuvant (NACT) and adjuvant chemotherapy (ACT).

RESULTS

Of the 91 MBC patients identified, 60 received chemotherapy. NACT recipients (n = 20, median age 46.5 y) were younger than ACT recipients (n = 40, median age 60.5 y, p < 0.001) but similar with regards to race and radiation receipt. There was no significant OS difference between NACT and ACT recipients (log-rank p = 0.15), which remained true when patients were stratified by age (≥50 y vs < 50 y).

CONCLUSIONS

Among MBC patients, NACT recipients were younger than ACT recipients, but there was no survival difference by treatment sequence.

Bone in the breast: A case report of a metaplastic breast cancer with osseous differentiation

Metaplastic breast carcinoma is an uncommon malignant tumor with various pathologic subtypes. Diagnosis is often challenging due to the wide spectrum of clinical and imaging presentations. Here, we present the case of a very rare subtype of metaplastic breast carcinoma—a mixed-type metaplastic breast cancer with osseous differentiation in a 55-year-old female patient. The clinical presentation, imaging-pathology diagnosis, and treatment options are reviewed. Knowing this rarely reported but aggressive breast cancer is very important for clinicians to establish a timely diagnosis for effective management.

Characteristics and prognosis of 17 special histologic subtypes of invasive breast cancers according to World Health Organization classification: comparative analysis to invasive carcinoma of no special type

BACKGROUND

Breast cancer is a heterogeneous disease with various histopathologic subtypes. Except for invasive carcinoma of no special type (NST), other subtypes are rare with limited data. The purpose of this study was to analyze the characteristics and prognosis of special histopathologic subtypes of breast cancer compared to NST.

METHODS

A total of 136,140 patients were analyzed using the Korean Breast Cancer Society Registry database between January 1996 and March 2019. The clinicopathologic features and survival outcomes of special type breast carcinoma were compared with those of NST.

RESULTS

The prevalence of special subtypes other than NST was 13.7% (n = 18,633). Compared to NST, patients with lobular, medullary, metaplastic, and micropapillary carcinoma had larger tumors (p < 0.001). Patients with mucinous, tubular, medullary, metaplastic, and cribriform carcinoma presented with less node metastasis (p < 0.001), contrary to patients with micropapillary carcinoma. Patients with lobular, mucinous, tubular, papillary, and cribriform carcinoma presented as luminal A subtype much more often (p < 0.001). Micropapillary carcinoma included more luminal B subtype (p < 0.001). Typically, medullary and metaplastic carcinoma included more triple-negative subtypes (p < 0.001). In survival analysis, only medullary (Hazard Ratio (HzR) 0.542, 95% CI 0.345 to 0.852, p = 0.008) and metaplastic carcinoma (HzR 1.655, 95% CI 1.317 to 2.080, p < 0.001) showed significantly different overall survival from NST by multivariate analysis.

CONCLUSION

Breast cancer had distinct clinicopathologic features according to histopathologic subtype. However, special types of breast cancer had similar survival outcomes compared to NST when adjusting for other prognostic factors, except for metaplastic carcinoma and medullary carcinoma.

Squamous cell carcinoma of the breast, are there two entities with distinct prognosis? A series of 39 patients

PURPOSE

Squamous cell carcinoma (SCC) of the breast is a rare entity of breast cancer, with a very poor prognosis, and whose pathophysiology is still unwell established. Therapeutic management is very heterogeneous due to its incomplete understanding. Nevertheless, it seems that two histological entities can be distinguished: pure SCC close to the cutaneous origin, and metaplastic squamous breast cancer (MSBC). The aim of this study is therefore to assess the difference in survival according to the histological type (SCC or MSBC) and to describe the demographic, clinical, and therapeutic characteristics of the two underlying populations.

METHODS

Our data came from a monocentric retrospective series of 39 patients treated between 1985 and 2018 at the Gustave Roussy Institute (France) for a breast SCC.

RESULTS

Of the 39 patients included, 64% had MSBC and 36% had a pure form. The overall and recurrence-free survival at 3 years [CI 95%] was 72.3% [56.9%; 87.0%] and 67.2% [51.2%; 83.2%], respectively. The overall 3-year survival of patients with MSBC was significantly lower than that with pure SCC: HR [CI 95%] 9.5 [1.2; 73.1], p = 0.008. The 3-year recurrence-free survival of patients with MSBC was also poorer: HR [CI 95%] 11.9 [1.6; 90.7], p = 0.002. Patients with MSBC also tended to be younger, have a large lesion size, and be more metastatic.

CONCLUSION

The histological nature of SCC seems to bring fundamental new elements to the therapeutic management as it impacts recurrence and survival. It should therefore be better characterized at diagnosis in order to possibly adapt treatments.

Comparison of outcomes between metaplastic and triple-negative breast cancer patients

Purpose

Metaplastic breast cancer (MBC) is a rare, aggressive variant of breast cancer that has been associated with poor clinical outcomes, as has triple-negative breast (TNBC) cancer. Limited studies compare the clinical characteristics and prognosis of MBC to TNBC. This study uses a large, contemporary US cancer database to compare clinical characteristics and survival outcomes for patients with MBC to those with TNBC.

Methods

The National Cancer Database was queried for women with cT1-4N1-3M0 MBC or TNBC diagnosed between 2004 and 2013 and treated with definitive surgery. Chi-squared analysis was performed to determine differences between the cohorts. Kaplan-Meier curves compared overall survival (OS), and Cox regression determined patient factors associated with OS.

Results

Altogether, 55,847 patients met the inclusion criteria; 50,705 (90.8%) had TNBC and 5,142 (9.2%) had MBC. Most patients had no comorbid conditions (82%), N0 disease (71%), poorly differentiated histology (77%), received chemotherapy (87%), and received radiation therapy (60%). Amongst all patients, patients with TNBC disease were observed to have greater OS than those with MBC (5-year OS 72.0% vs 55.8%, p < 0.001). The greater observed OS for patients with TNBC persisted when controlling for stage and when comparing propensity score matched cohorts. On Cox regression, lower age, T1 status, N0 status, chemotherapy, TNBC disease, and radiation therapy (RT) were associated with improved OS.

Conclusions

MBC had an association with poorer OS compared to TNBC, while RT and chemotherapy receipt were associated with improved OS for patients regardless of stage. Further studies are needed to corroborate the conclusions herein.

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Metaplastic breast cancer is associated with poor clinical outcomes.

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Metaplastic breast cancer associated with worse survival than patients with triple negative invasive ductal carcinoma.

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Radiation therapy and chemotherapy associated with improved survival for patients with metaplastic breast cancer.

A reproducible scaffold-free 3D organoid model to study neoplastic progression in breast cancer

While 3D cellular models are useful to study biological processes, gel-embedded organoids have large variability. This paper describes high-yield production of large (~1 mm diameter), scaffold-free, highly-spherical organoids in a one drop-one organoid format using MCF10A cells, a non-tumorigenic breast cell line. These organoids display a hollow lumen and secondary acini, and express mammary gland-specific and progenitor markers, resembling normal human breast acini. When subjected to treatment with TGF-β, the hypoxia-mimetic reagent CoCl2, or co-culture with mesenchymal stem/stromal cells (MSC), the organoids increase collagen I production and undergo large phenotypic and morphological changes of neoplastic progression, which were reproducible and quantifiable. Advantages of this scaffold-free, 3D breast organoid model include high consistency and reproducibility, ability to measure cellular collagen I production without noise from exogenous collagen, and capacity to subject the organoid to various stimuli from the microenvironment and exogenous treatments with precise timing without concern of matrix binding. Using this system, we generated organoids from primary metaplastic mammary carcinomas of MMTV-Cre;Ccn6fl/fl mice, which retained the high grade spindle cell morphology of the primary tumors. The platform is envisioned to be useful as a standardized 3D cellular model to study how microenvironmental factors influence breast tumorigenesis, and to potential therapeutics.

CCN6 regulates IGF2BP2 and HMGA2 signaling in metaplastic carcinomas of the breast

PURPOSE

Metaplastic breast carcinomas are an aggressive subtype of triple-negative breast cancer (TNBC) in which part or all of the adenocarcinoma transforms into a non-glandular component (e.g., spindled, squamous, or heterologous). We discovered that mammary-specific Ccn6/Wisp3 knockout mice develop mammary carcinomas with spindle and squamous differentiation that share upregulation of the oncofetal proteins IGF2BP2 (IMP2) and HMGA2 with human metaplastic carcinomas. Here, we investigated the functional relationship between CCN6, IGF2BP2, and HMGA2 proteins in vitro and in vivo, and their expression in human tissue samples.

METHODS

MMTV-cre;Ccn6^fl/fl tumors and spindle TNBC cell lines were treated with recombinant CCN6 protein or vehicle. IGF2BP2 was downregulated using shRNAs in HME cells with stable CCN6 shRNA knockdown, and subjected to invasion and adhesion assays. Thirty-one human metaplastic carcinomas were arrayed in a tissue microarray (TMA) and immunostained for CCN6, IGF2BP2, and HMGA2.

RESULTS

CCN6 regulates IGF2BP2 and HMGA2 protein expression in MMTV-cre;Ccn6^fl/fl tumors, in MDA-MB-231 and - 468, and in HME cells. CCN6 recombinant protein reduced IGF2BP2 and HMGA2 protein expression, and decreased growth of MMTV-cre;Ccn6^fl/fl tumors in vivo. IGF2BP2 shRNA knockdown was sufficient to reverse the invasive abilities conferred by CCN6 knockdown in HME cells. Analyses of the TCGA Breast Cancer Cohort (n = 1238) showed that IGF2BP2 and HMGA2 are significantly upregulated in metaplastic carcinoma compared to other breast cancer subtypes. In clinical samples, low CCN6 is frequent in tumors with high IGF2BP2/HMGA2 with spindle and squamous differentiation.

CONCLUSIONS

These data shed light into the pathogenesis of metaplastic carcinoma and demonstrate a novel CCN6/IGF2BP2/HMGA2 oncogenic pathway with biomarker and therapeutic implications.

Early and Locally Advanced Metaplastic Breast Cancer: Presentation and Survival by Receptor Status in Surveillance, Epidemiology, and End Results (SEER) 2010-2014

BACKGROUND

Metaplastic breast cancer (MBC) is a rare disease subtype characterized by an aggressive clinical course. MBC is commonly triple negative (TN), although hormone receptor (HR) positive and human epidermal growth receptor 2 (HER2) positive cases do occur. Previous studies have reported similar outcomes for MBC with regard to HR status. Less is known about outcomes for HER2 positive MBC.

MATERIALS AND METHODS

Surveillance, Epidemiology, and End Results Program data were used to identify women diagnosed 2010-2014 with MBC or invasive ductal carcinoma (IDC). Kaplan-Meier curves estimated overall survival (OS) and multivariate Cox models were fitted. For survival analyses, only first cancers were included, and 2014 diagnoses were excluded to allow for sufficient follow-up.

RESULTS

Our MBC sample included 1,516 women. Relative to women with IDC, women with MBC were more likely to be older (63 vs. 61 years), black (16.0% vs. 11.1%), and present with stage III disease (15.6% vs. 10.8%). HER2 positive and HER2 negative/HR positive MBC tumors represented 5.2% and 23.0% of cases. For MBC overall, 3-year OS was greatest for women with HER2 positive MBC (91.8%), relative to women with TN (75.4%) and HER2 negative/HR positive MBC (77.1%). This difference was more pronounced for stage III MBC, for which 3-year OS was 92.9%, 47.1%, and 42.2% for women with HER2 positive, TN, and HER2 negative/HR positive MBC, respectively. A multivariate Cox model of MBC demonstrated that HER2 positive tumors (relative to TN) were associated with improved survival (hazard ratio = 0.32, 95% confidence interval [CI] 0.13-0.79). In a second Cox model of exclusively HER2 positive tumors, OS did not differ between MBC and IDC disease subtypes (hazard ratio = 1.16, 95% CI 0.48-2.81).

CONCLUSION

In this contemporary, population-based study of women with MBC, HER2 but not HR status was associated with improved survival. Survival was similar between HER2 positive MBC and HER2 positive IDC. This suggests HER2 positive MBC is responsive to HER2-directed therapy, a finding that may offer insights for additional therapeutic approaches to MBC.

IMPLICATIONS FOR PRACTICE

This population-based study reports recent outcomes, by receptor status, for women with metaplastic breast cancer. Survival in metaplastic breast cancer is not impacted by hormone receptor status. To the authors' knowledge, this is the first report indicating that women with human epidermal growth receptor 2 (HER2) positive metaplastic breast cancer have survival superior to women with HER2 negative metaplastic breast cancer and survival similar to women with HER2 positive invasive ductal carcinoma. This information can be used for counseling patients diagnosed with metaplastic breast cancer. Further understanding of HER2 positive metaplastic breast cancer could offer insights for the development of therapeutic approaches to metaplastic breast cancer more broadly.

Matricellular CCN6 (WISP3) protein: a tumor suppressor for mammary metaplastic carcinomas

Located at 6q22-23, Ccn6 (WISP3) encodes for a matrix-associated protein of the CCN family, characterized by regulatory, rather than structural, roles in development and cancer. CCN6, the least studied member of the CCN family, shares the conserved multimodular structure of CCN proteins, as well as their tissue and cell-type specific functions. In the breast, CCN6 is a critical regulator of epithelial-to-mesenchymal transitions (EMT) and tumor initiating cells. Studies using human breast cancer tissue samples demonstrated that CCN6 messenger RNA and protein are expressed in normal breast epithelia but reduced or lost in aggressive breast cancer phenotypes, especially inflammatory breast cancer and metaplastic carcinomas. Metaplastic carcinomas are mesenchymal-like triple negative breast carcinomas, enriched for markers of EMT and stemness. RNAseq analyses of the TCGA Breast Cancer cohort show reduced CCN6 expression in approximately 50% of metaplastic carcinomas compared to normal breast. Our group identified frameshift mutations of Ccn6 in a subset of human metaplastic breast carcinoma. Importantly, conditional, mammary epithelial-cell specific ccn6 (wisp3) knockout mice develop invasive high-grade mammary carcinomas that recapitulate human spindle cell metaplastic carcinomas, demonstrating a tumor suppressor function for ccn6. Our studies on CCN6 functions in metaplastic carcinoma highlight the potential of CCN6 as a novel therapeutic approach for this specific type of breast cancer.

Metaplastic breast carcinoma: Analysis of 31 cases from a single institute

PURPOSE

Metaplastic carcinoma of the breast (MBC) accounts for less than 1% of all mammary tumors. This study aimed at revision of the clinico-pathological features, treatment strategy and outcome for MBC patients presented to the Kuwait Cancer Control Center to define the clinical behavior and prognostic factors of these neoplasms in our population.

PATIENT AND METHODS

Thirty-one patients were retrieved from our surgical pathology registry between January 2005 and December 2014. Medical records were revised regarding the clinico-pathological features and treatment outcome.

RESULTS

MBC represented 1% of our breast cancer patients. The median age was 50years (32-70years). Two patients presented with metastatic disease. Mastectomy was done for 24 patients and 7 had conservative surgery. The median tumor size at the time of surgery was 5.5cm (1.5-12cm). Axillary nodes were negative in 21 patients (N0), 5 patients were N1, 4 patients were N2 and one Nx. Three histological subtypes were presented: carcinosarcoma (7 cases), squamous cell carcinoma/IDC with squamous differentiation (15 cases), high grade IDC with metaplastic differentiation (9 cases). Immunohistochemically, 26 were negative hormone receptors and all were negative for Her2/neu overexpression. Chemotherapy was used in 28 patients, and adjuvant radiotherapy in 24 patients. The median follow-up was 47months (7-126months), six patients lost follow-up. The 5-year OS was 69% and 5-year PFS was 50%.

CONCLUSION

MBC is a rare entity among breast carcinoma in Kuwait. Most of the cases present with poor prognostic indicators and often show lack of expression of ER, PR and Her2/neu.

Metaplastic breast carcinoma with osseous differentiation: A rare case report

INTRODUCTION

Metaplastic breast carcinoma (MBC) is a rare type of breast cancer. Osseous differentiation is a very rare subtype. Reporting this kind of case is important because its clinical course and line of management are poorly mentioned in the literatures. We present a very rare case of MBC with osseous differentiation. A 48-year-old female presented with painless hard mass of the left breast. Examination and investigations showed MBC with osseous differentiation. She was managed by operation with adjuvant chemotherapy.

CONCLUSION

MBC with osseous differentiation is a very rare type of breast carcinoma presenting with hard mass and managed by mastectomy, axillary lymph node sampling and adjuvant chemotherapy.

Prognostic factors in the myoepithelial-like spindle cell type of metaplastic breast cancer

Metaplastic breast carcinoma (MBC) comprises a heterogeneous group of tumors with difficult to predict biological behavior. A subset of MBC, characterized by spindle-shaped tumor cells with a myoepithelial-like immunophenotype, was entered into a retrospective study (n = 42, median follow-up time 43 months). Molecular parameters (DNA sequences of mutation hot spots in AKT1, ALK, APC, BRAF, CDH1, CTNNB1, EGFR, ERBB2, FBXW7, FGFR2, FOXL2, GNAQ, GNAS, KIT, KRAS, MAP2K1, MET, MSH6, NRAS, PDGFRA, PIK3CA, PTEN, SF3B1, SMAD4, SRC, SRSF2, STK11, TP53, and U2AF1; copy numbers for EGFR, c-myc, FGFR, PLAG, c-met) were assessed. None of the patients had axillary lymph node involvement. In 13 cases, local recurrence developed after surgery (30.9 %). Distant metastasis occurred in seven patients (17 %; four after local recurrence). The most frequent genetic alteration was PIK3CA mutation (50 % of cases). None of the pathological parameters (size, grade, stage, Ki-67 labeling index) was significantly associated with disease-free survival (DFS) or overall survival (OS). PIK3CA mutation, especially the H1047R type, tended to adversely affect OS. Type of resection (mastectomy vs. breast-conserving therapy, width of margins) or adjuvant radiotherapy had no influence on DFS or OS, whereas in the group treated with radio-/chemotherapy, no local recurrence or metastasis and no death occurred. We conclude that the spindle cell type of MBC with myoepithelial features exhibits a higher frequency of PIK3CA mutation than other types of metaplastic or basal-like breast cancer and may benefit from combined radio-/chemotherapy. Classical pathological parameters are not helpful in identifying the high-risk tumors among this subgroup of MBC.

Low-grade adenosquamous carcinoma of the breast: A diagnostic and clinical challenge

Adenosquamous carcinoma of the breast (ASBC) is a rare variant of metaplastic breast cancer with both glandular as well as squamous differentiation. Their lack of distinct imaging characteristics, sometimes subtle histological characteristics and overlapping features with other benign lesions pose a diagnostic challenge. Unlike other forms of metaplastic breast cancer, low-grade adenosquamous carcinoma (LGAC) tends to follow an indolent course with favourable prognosis. We reviewed eight cases of LGAC in our institution from June 2005 to March 2014. In six cases, LGAC was only found after excisional biopsy. In our patients, LGAC frequently co-existed with other forms of breast pathology. Two patients had incidental findings of LGAC alongside their primary malignant tumour (adenoid cystic carcinoma and invasive ductal carcinoma in one, four foci between 0.5 and 4.0 mm within a radial sclerosing lesion adjacent to a malignant phyllodes tumour in the other). A further four patients had LGAC within a complex sclerosing lesion. One patient had a focus of LGAC within a fibroadenoma. One had a focus of LGAC within a benign phyllodes tumour. None of the patients had evidence of nodal involvement. A high degree of suspicion is recommended as such lesions tend to be incidental histological findings within benign tumours or within complex sclerosing lesions. Although the risk of nodal and distant metastasis is low, the potential for local recurrence necessitates aggressive local excision with margin clearance. The role of axillary dissection has yet to be defined and routine sentinel node biopsy and axillary clearance may not be necessary in view of rarity of nodal metastasis in literature. Benefit from adjuvant radiotherapy or chemotherapy is not clearly defined. All eight patients in our study have shown no evidence of recurrence after definitive surgery but longer periods of surveillance is required.