Metaplastic Carcinoma Of The Breast Research Articles

A Single-Center 18-Year Series of 73 Cases of Metaplastic Carcinoma of the Breast.

To examine the clinical management of metaplastic breast cancer (MeBC), particularly the role of chemotherapy. This retrospective study included patients with MeBC (n = 73) from a tertiary breast cancer center: the "Centre des Maladies du Sein of the CHU de Québec-Université Laval." The specimens were reviewed by two pathologists. Patient and tumor characteristics, systemic therapy (neoadjuvant and adjuvant), disease-free survival (DFS), and overall survival (OS) were recorded. The median follow-up was 57.2 months. The mean tumor size was 39.5 ± 32.1 (range, 1-200) mm. Most were in grade 3 (75.3%), without evidence of clinical nodal involvement (75.3%), and triple-negative (79.5%). Chemotherapy was given to 49 (67.1%) patients. Thirty-seven patients (50.7%) underwent a mastectomy, and 22/37 (59.5%) received radiotherapy. Adjuvant chemotherapy was given to 36 patients (49.3%), and nine (12.3%) patients were treated with neoadjuvant chemotherapy. The 5-year OS and DFS rates were 60.2% and 66.8%. Among the nine patients who received neoadjuvant chemotherapy, three (33.3%) achieved a partial response, three (33.3%) had stable disease, and three (33.3%) had disease progression. The use of chemotherapy, especially in the adjuvant setting, had a significant positive effect on 5-year OS (P=0.003) and 5-year DFS (P=0.004). Nodal involvement was associated with worse OS (P=0.049) but similar DFS (P=0.157). Lumpectomy was associated with better 5-year OS (P < 0.0001) and DFS (P=0.0002) compared with mastectomy. MeBC represents a rare heterogeneous group of malignancies with poor prognosis. Adjuvant chemotherapy was associated with improved OS and DFS. Patients should be carefully selected for neoadjuvant chemotherapy.

Genetic analysis of low-grade adenosquamous carcinoma of the breast progressing to high-grade metaplastic carcinoma

PurposeLow-grade adenosquamous carcinoma (LGASC) is a rare type of metaplastic carcinoma of the breast (MBC) with an indolent clinical course. A few LGASC cases with high-grade transformation have been reported; however, the genetics underlying malignant progression of LGASC remain unclear.MethodsWe performed whole-genome sequencing analysis on five MBCs from four patients, including one case with matching primary LGASC and a lymph node metastatic tumor consisting of high-grade MBC with a predominant metaplastic squamous cell carcinoma component (MSC) that progressed from LGASC and three cases of independent de novo MSC.ResultsUnlike de novo MSC, LGASC and its associated MSC showed no TP53 mutation and tended to contain fewer structural variants than de novo MSC. Both LGASC and its associated MSC harbored the common GNAS c.C2530T:p.Arg844Cys mutation, which was more frequently detected in the cancer cell fraction of MSC. MSC associated with LGASC showed additional pathogenic deletions of multiple tumor-suppressor genes, such as KMT2D and BTG1. Copy number analysis revealed potential 18q loss of heterozygosity in both LGASC and associated MSC. The frequency of SMAD4::DCC fusion due to deletions increased with progression to MSC; however, chimeric proteins were not detected. SMAD4 protein expression was already decreased at the LGASC stage due to unknown mechanisms.ConclusionNot only LGASC but also its associated high-grade MBC may be genetically different from de novo high-grade MBC. Progression from LGASC to high-grade MBC may involve the concentration of driver mutations caused by clonal selection and inactivation of tumor-suppressor genes.

Metaplastic squamous cell carcinoma of the breast – A rare case report

Metaplastic carcinomas of the breast are unusual conditions and account for 0.25% to 1% of annual breast malignancies. Among these, primary metaplastic squamous cell carcinoma (SCC) of the breast is an extremely rare entity occurring in less than 0.1% of all breast carcinomas. Management protocol and survival outcome for metaplastic breast carcinoma is relatively unknown because of the rarity of the disease, but studies suggest that removal of the tumor and adjuvant radiotherapy has the greatest impact. In this paper, we report the occurrence of this rare lesion in a 71-year-old lady who was treated and is recovering uneventfully. Early diagnosis and radical upfront surgery may warrant a good prognosis, as demonstrated in this case report.

Metaplastic Carcinoma of the Breast: Case Series of a Single Institute and Review of the Literature.

Metaplastic carcinoma of the breast (MpBC) is a very rare and aggressive type of breast cancer. Data focusing on MpBC are limited. The aim of this study was to describe the clinicopathological features of MpBC and evaluate the prognosis of patients with MpBC. Eligible articles about MpBC were identified by searching CASES SERIES gov and the MEDLINE bibliographic database for the period of 1 January 2010 to 1 June 2021 with the keywords metaplastic breast cancer, mammary gland cancer, neoplasm, tumor, and metaplastic carcinoma. In this study, we also report 46 cases of MpBC stemming from our hospital. Survival rates, clinical behavior, and pathological characteristics were analyzed. Data from 205 patients were included for analysis. The mean age at diagnosis was 55 (14.7) years. The TNM stage at diagnosis was mostly stage II (58.5%) and most tumors were triple negative. The median overall survival was 66 (12-118) months, and the median disease-free survival was 56.8 (11-102) months. Multivariate Cox regression analysis revealed that surgical treatment was associated with decreased risk of death (hazard ratio 0.11, 95% confidence interval 0.02-0.54, p = 0.01) while advanced TNM stage was associated with increased risk of death (hazard ratio 1.5, 95% confidence interval 1.04-2.28, p = 0.03). Our results revealed that surgical treatment and TNM stage were the only independent risk factors related to patients' overall survival.

The efficacy of gemcitabine combined with immunotherapy in a patient with metastatic metaplastic squamous cell carcinoma of the breast

Abstract Objectives Metaplastic squamous cell carcinoma of the breast is a rare form of breast carcinoma for which there is currently no standard treatment. Case presentation We report the case of a 33-year-old woman with enlargement in her left breast who was diagnosed with metaplastic squamous cell carcinoma by core needle biopsy. The patient underwent a modified radical mastectomy. The immunohistochemistry showed it was a triple-negative breast cancer: progesterone receptor-negative (PR-), estrogen receptor-negative (ER-), and human epidermal growth factor receptor 2 -negative (HER2-). The patient received 6 cycles of adjuvant chemotherapy with nab-paclitaxel and carboplatin. One year later, she developed lung metastases from squamous cell carcinoma. Immunohistochemical results remained triple-negative (ER-, PR- and HER2-). The patient then received gemcitabine combined with immunotherapy. The patient has been assessed as stable disease so far. Conclusions Immunotherapy combined with gemcitabine showed good efficacy in the treatment of metastatic metaplastic squamous cell carcinoma of the breast after nab-paclitaxel combined with platinum-based therapy.

Metaplastic carcinoma of the breast: matched cohort analysis of recurrence and survival.

Metaplastic breast carcinoma (MBC) is a rare subtype of breast cancer, defined as mammary carcinoma with squamous or mesenchymal differentiation, that may include spindle cell, chondroid, osseous, or rhabdomyoid differentiation patterns. The implications of MBC recurrence and survival outcomes remains unclear. Cases were ascertained from a prospectively maintained institutional database of patients treated from 1998 to 2015. Patients with MBC were matched 1:1 to non-MBC cases. Cox proportional-hazards models and Kaplan-Meier estimates were used to evaluate outcome differences between cohorts. 111 patients with MBC were matched 1:1 with non-MBC patients from an initial set of 2400 patients. Median follow-up time was 8years. Most patients with MBC received chemotherapy (88%) and radiotherapy (71%). On univariate competing risk regression, MBC was not associated with locoregional recurrence (HR = 1.08; p = 0.8), distant recurrence (HR = 1.65; p = 0.092); disease-free survival (HR = 1.52; p = 0.065), or overall survival (HR = 1.56; p = 0.1). Absolute differences were noted in 8-year disease-free survival (49.6% MBC vs 66.4% non-MBC) and overall survival (61.3% MBC vs 74.4% non-MBC), though neither of these reached statistical significance (p = 0.07 and 0.11, respectively). Appropriately-treated MBC may exhibit recurrence and survival outcomes that are difficult to distinguish from those of non-MBC. While prior studies suggest that MBC has a worse natural history than non-MBC triple-negative breast cancer, prudent use of chemotherapy and radiotherapy may narrow these differences, although studies with more power will be required to inform clinical management. Longer follow-up among larger populations may further elucidate the clinical and therapeutic implications of MBC.

Markers associated with genomic instability, immunogenicity and immune therapy responsiveness in Metaplastic carcinoma of the breast: Expression of γH2AX, pRPA2, P53, PD-L1 and tumor infiltrating lymphocytes in 76 cases

BackgroundMetaplastic breast cancer (MpBC) is an aggressive subtype of breast carcinoma that is often resistant to conventional chemotherapy. Therefore, novel treatment strategies are urgently needed. Immune check point inhibitors have shown activity in programmed death-ligand 1 (PD-L1) – positive metastatic triple negative breast carcinoma (TNBC), which raises the possibility that immunotherapy may also be effective in MpBC as most of the MpBCs are triple negative. The aim of the present study was to assess genomic instability and immunogenicity in tumor specimens of patients with MpBC.MethodsA total of 76 patients diagnosed with MpBC over a 15-year period were included in the study. We performed immunohistochemical analyses for tumor cell PD-L1, immune cell PD-L1 and p53 on tissue microarrays (TMAs), analyzed stromal and intratumoral tumor infiltrating lymphocytes (TILs) from hematoxylin and eosin-stained (H&E) slides and scored gamma-H2AX (γH2AX) and phosphorylated-RPA2 (pRPA2) from whole tissue sections. We correlated marker expression with clinicopathologic features and clinical outcome.ResultsAll tumors expressed γH2AX and pRPA2 with median expressions of 43% and 44%. P53- (68%), tumor cell PD-L1- (59%) and immune cell PD-L1-positivity (62%) were common in MpBCs. Median stromal TIL and intratumoral TIL counts were 5% and 0. The spindle and squamous cell carcinomas expressed the highest levels of PD-L1 and TILs, and carcinoma with mesenchymal differentiation the lowest.ConclusionsMpBC appears to be an immunogenic cancer with high genomic instability and frequent PD-L1-positivity, implying that check point inhibitors might be effective in MpBC. Expression levels of PD-L1 and TILs varied across different histologic subtypes, suggesting that immunotherapy might be less effective in carcinoma with mesenchymal differentiation.

Metaplastic carcinoma of the breast with mesenchymal differentiation: a rare case report and literature review

Metaplastic breast carcinoma with mesenchymal differentiation (MCMD), formerly known as carcinosarcoma, is a very rare and aggressive tumor that has recently been classified as a subtype of metaplastic breast carcinoma. It accounts for 0.08%–0.2% of all breast cancers, with only a few cases reported in the literature. Here we report a case of a 56-year-old woman with a large, hard lump in her right breast, with no history of breast cancer in first degree relatives. Symptoms were present 6 months before presentation. After hospitalization and following physical evaluation, USG, mammography, biopsy and immunohistochemistry, the diagnosis of metaplastic carcinoma with mesenchymal differentiation was established. Two of 11 axillary lymph nodes were positive for metastases. The optimal treatment modality for metaplastic carcinoma is not yet established due to its rarity and heterogeneity. Modified radical mastectomy is the preferred surgical procedure because a large tumor size is a contraindication for breast conserving surgery. In conclusion, a patient with such an enlargement of the breast mass must be carefully evaluated, for the correct diagnosis of a possible metaplastic carcinoma.

Metaplastic carcinoma of the breast: a case report

Metaplastic carcinoma is a rare but heterogeneous group of neoplasm of breast, accounting for about 1% of all breast carcinomas. Metaplastic carcinomas may be either low-grade tumors (e.g., adenosquamous carcinoma or spindle cell carcinoma), or high-grade tumors (e.g., squamous cell carcinoma, or spindle cell carcinoma). We report a case of metaplastic breast carcinoma in a 72-year-old lady. The clinical, radiological and histological characteristics are discussed.

Metaplastic Carcinoma of the Breast: MRI Features with Clinical and Histopathologic Correlation

Metaplastic carcinoma of the breast (MCB) is a rare type of breast carcinoma, and there are only limited data about the MRI findings of MCB. This article aimed to review the MRI features of MCB and correlate the MRI findings with clinical and histopathologic characteristics. A total of 23 patients were enrolled from a signal institution. The clinical data, histological diagnosis and MRI findings were retrospectively reviewed. The average age of the 23 patients was 51.6 years. Twenty-one (91.3%) patients presented with a palpable mass. Squamous cell carcinoma was the most common subtype (10/23, 43.5%). Axillary lymph node metastasis was detected in 4 (17.4%) patients. The immunohistochemical profile showed the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor-2 (Her-2) expression were negative in 87.0%, 95.7%, and 91.3% of the patients respectively. On MRI, most cases exhibited an irregular mass (18/23, 78.3%) with high signal intensity on T2-weighted images (22/23,95.7%), non-circumscribed margin (19/23, 82.6%), heterogeneous enhancement (13/23, 56.5%), Type III (12/23, 52.2%) time intensity curve, and diffusion restriction (20/23, 87.0%) on diffusion weighted images (DWI). MCB most commonly demonstrated definitely malignant MRI features, which may reflect the histopathologic characteristic of this rare and aggressive breast carcinoma.

Clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma of the breast

Objective: To investigate the clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma (MSCC) of the breast. Methods: A total of 47 MSCC cases diagnosed in the Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from January 2010 to December 2021 were reviewed. The clinical information (including the follow-up data of HER2 positive patients) and pathological features were collected and analyzed. Results: All of the patients were female. Among the 47 cases, 25 were pure squamous cell carcinoma (PSCC) and 22 were mixed metaplastic carcinoma with squamous cell component (MMSC). The median age of the patients was 54 years (range, 29-84 years). The maximum diameter of the mass ranged from 0.8 to 10.0 cm, with a mean value of 3.3 cm, 85.7% (24/28) of the cases were smaller than 5 cm, and only 4 cases were larger than or equal to 5 cm. 89.5% of the MMSC presented with a solid mass. Cystic changes were more commonly found in the PSCC group (50%, P<0.05) than the MMSC group. 36.7% (11/30) of the patients had lymph node metastasis at the time of diagnosis. The squamous cell carcinoma component in all cases showed diffuse or patchy expression of p63, p40 and CK5/6. 55.3% (26/47) of the cases showed triple-negative phenotype. Among the 7 HER2-positive patients, 6 were MMSC group, which had a significantly higher rate of HER2-positivity than that in the PSCC group (1 case). In 1 MMSC case, immunohistochemistry showed HER2 2+in the invasive ductal carcinoma component and HER2 negativity (0) in the squamous cell carcinoma component, but HER2 FISH was negative in invasive ductal carcinoma and positive in squamous cell carcinoma component. Six HER2-positive MSCC patients received anti-HER2-targeted therapy, including two patients who received neoadjuvant chemotherapy combined with anti-HER2-targeted therapy before surgery. One patient achieved pathological complete remission, while the other achieved partial remission (the residual tumors were squamous cell carcinoma components). After 9-26 months of follow-up, four patients had no disease progression, two patients developed pulmonary metastases, and one patient showed local recurrence. Conclusions: MSCC is a group of heterogeneous diseases. PSCC and MMSC may be two different entities. Most of the MSCC are triple-negative and HER2 positivity is more commonly seen in MMSC with invasive ductal carcinoma component. Some HER2-positive MSCC patients can achieve complete remission or long-term progression-free survival after receiving anti-HER2 targeted therapy, but the squamous cell carcinoma component may be less sensitive to targeted therapy than the invasive ductal carcinoma component.

Metaplastic carcinoma of the breast: real-world outcome from a tertiary cancer centre in India.

Metaplastic carcinoma (MPC) is a rare subgroup of breast tumours accounting for <5% of all invasive breast cancers. Histologically confirmed 40 MPC from January 2001 to December 2018 were identified from our electronic database: stage I 2.5% (n = 1), stage II 40% (n = 16), stage III 45% (n = 18) and stage IV 12.5% (n = 5). The mean tumour size was 6 cm, node-negative in 60%, and hormone receptor-negative in 75%. Among the 35 non-metastatic patients, 17 (48.6%) received initial neoadjuvant treatment (NAT), followed by surgery, and only 1 had a complete pathological response. At a median follow-up of 60 months, 17% (n = 6) had a recurrence. All six of them had lung metastasis. The 5-year overall survival (OS) and disease-free survival were 64.4% and 66.3%, respectively. Age more than 46 years (p = 0.027), tumour size more than 5 cm (p = 0.037), and nodal positivity (p = 0.001) were predictors of OS. In node-positive patients, the 5-year OS in those who underwent initial surgery was 80% and after NAT was 21.4% (p = 0.069). In node-negative patients, the 5-year OS after initial surgery was 83.3% and after NAT was 90% (p = 0.380). A statistical significance could not be demonstrated due to the small number of patients. Due to chemoresistance, the concept of initial NAT in MPC of the breast is a subject to be studied in the future. Upfront surgery should be considered for operable diseases (including stage III), followed by a decision on adjuvant therapy. Optimal treatment and effective systemic therapy regimens are yet to be defined.

Metaplastic Carcinoma of the Breast, A Case Study

Breast carcinosarcoma, metaplastic neoplasm of the breast, a rare type of breast tumors that accounts about 0.08 to 0.2 % of all breast cancers. carcinosarcoma is a mixed type of neoplastic cells. carcino related to epithelial cells origin. Sarcoma is a mesenchymal cell malignant tumor. This is a sever bad prognosis cancer. A few cases was reported about breast carcinosarcoma, here in we have a case of 58 female patient that has a late stage of breast mass that was diagnosed as a breast carcinosarcoma. In this case report we will show the presentation of the patient, discuss the risk factors and put our treatment plan.

Abstract P4-07-07: Metaplastic carcinoma of the breast has comparable prognosis to non-metaplastic triple negative breast cancer despite poor response to chemotherapy

Abstract Introduction Metaplastic carcinoma (MC) of the breast is a rare pathologic entity accounting for &amp;lt;1% of all invasive breast cancers and is generally negative for hormone receptors and HER2. They often show more aggressive characteristics and are resistant to treatment. Although triple negative breast cancers (TNBCs) have good response to neoadjuvant chemotherapy (NAC) and a pathologic complete response (pCR) rate of about 40%, benefit of NAC for MC is not clear. The aim of this study was to compare the Clinicopathologic characteristics and prognosis of MC with non-MC TNBC, and assess the usefulness of NAC for MC. Methods Retrospective chart review of TNBC patients who underwent breast surgery at Seoul National University Hospital between January 2000 and December 2018 were included for analysis. Clinicopathologic features including age, TNM stage, Ki-67 and histologic grade were collected. For patients who had received NAC, tumor size on ultrasound before NAC and pathologic size of residual tumor was used to assess responsiveness to NAC. We used 3:1 propensity score matching according to age, neoadjuvant chemotherapy, pT stage, pN stage. Kaplan-Meier analysis and log-rank test were performed. Results Among 1783 TNBC patients included for analysis, 82 (4.59%) were MC and 1701 (95.34%) were non-MC. MC had a worse DFS and OS. After propensity score matching, there was no difference in survival outcomes. The 5-year disease-free survival and overall survival between MC vs. non-MC TN was 61.9% vs. 73.0% (HR 1.379, 95% CI 0.594-3.202, p-value = 0.430) and 71.4% vs. 74.6% (HR 1.007, 95% CI 0.393-2.579, p-value = 0.480), respectively. The proportion of patients who received NAC among MC and propensity matched non-MC TNBC were 21/82 (25.6%) and 63/1701 (3.7%), respectively. The pathologic complete response rate for all and propensity score matched non-MC TNBC was 76/364 (20.9%) and 11/63 (17.5%), respectively, whereas no MC patients achieved a pathologic complete response (HR 1.404 95% CI 1.213-1.624, p-value = 0.058). Conclusions MC has comparable prognosis compared to non-MC TNBC in terms of disease-free survival and overall survival, while showing lower rate of pathologic complete response after NAC. Upfront surgery may be more beneficial for MC. A prospective study with larger number of patients evaluating the role of NAC in MC is warranted. Citation Format: Changjin Lim, Jang-il Kim, Yireh Han, Jong-ho Cheun, Ji Gwang Jung, Hong Kyu Kim, Hyeong-Gon Moon, Wonshik Han, Han-Byoel Lee. Metaplastic carcinoma of the breast has comparable prognosis to non-metaplastic triple negative breast cancer despite poor response to chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-07-07.

Abstract P1-12-03: Metaplastic carcinoma of the breast: A single-center 18-year series of 73 cases

Abstract Background: Metaplastic breast cancer (MeBC) is a rare subtype accounting for 0.2%-5% of all invasive breast cancer. They are characterized by an aggressive course and even a worse prognosis than triple-negative breast cancer (TNBC). The literature suggests that MeBCs are relatively chemoresistant; still, the patients often receive adjuvant or neoadjuvant chemotherapy during the course of treatment. This study aimed to examine the clinical management of MeBC, particularly the role of chemotherapy. Methods: This retrospective study included patients with MeBC (n=73) from the Centre des Maladies du Sein du CHU de Québec-Université Laval. The specimens were reviewed by two pathologists. Patient and tumor characteristics, systemic therapy (neoadjuvant and adjuvant), disease-free survival (DFS), and overall survival (OS) were recorded. Results: The median follow-up was 57.2 months. The mean tumor size was 39.5±32.1 (range, 1-200) mm. The vast majority had grade 3 (76.7%), no evidence of clinical nodal involvement (78.1%), and triple-negative (79.5%) disease. This population included one case (1.4%) of low-grade adenosquamous breast carcinoma, one (1.4%) of fibromatosis-like metaplastic carcinoma, 11 (15.1%) of spindle cell carcinoma, 13 (17.8%) of epidermoid carcinoma, 18 (24.7%) of MeBC with heterologous mesenchymal differentiation, and 29 (39.7%) of mixed MeBC. Chemotherapy was given to 53 (72.6%) patients. Thirty-seven patients (50.7%) had a lumpectomy, and 34/37 (91.9%) received adjuvant radiotherapy. Thirty-six patients (49.3%) had mastectomy and 22/36 (61.1%) received radiotherapy. The 5-year DFS was 55.6%, and the 5-year OS was 63.5 %. On univariable analyses, higher cT stage (cT3-4) was associated with poorer DFS and OS compared to cT1-2, respectively 13.4% vs. 70.7% (P&amp;lt;0.0001) and 19.9% vs. 82.8% (P&amp;lt;0.0001). Nodal involvement significantly influenced DFS (31.3% vs. 63.0%, P=0.011) and OS (37.5% vs. 71.6%; P=0.009). Lumpectomy was associated with a better 5-year DFS (78.4% vs. 34.0%, P&amp;lt;0.0001) and OS (90.6% vs. 38.8%, P&amp;lt;0.0001). The use of chemotherapy had a significant positive effect on 5-year DFS (64.2% vs. 31.9%, P=0.006; hazard ratio (HR)=0.45, 95% confidence interval (CI)=0.22-0.92, P=0.009) as well as 5-year OS (69.7% vs. 45.1%, P=0.035; HR=0.52, 95%CI=0.28-0.95 P=0.041). However, radiation therapy did not influence DFS (P=0.420) and OS (P=0.316). Nine patients received neoadjuvant chemotherapy; five had nodal involvement. One patient had a complete response (11.1%), five (55.6%) had a partial response, and three (33%) had progressive disease. The 5-year DFS and OS were lower for neoadjuvant chemotherapy compared with adjuvant chemotherapy (DFS: 27.8% vs. 71.5%, P=0.006; OS: 33.3% vs. 79.2%, P=0.001), but disease was more advanced in patients with neoadjuvant chemotherapy (cT3-4: 88.9% vs. 11.9%, P&amp;lt;0.0001). Conclusion: MeBC represents a rare heterogeneous group of malignancies with poor prognosis. Chemotherapy was associated with improved DFS and OS. Patients for neoadjuvant chemotherapy should be carefully selected. Citation Format: Kassandra J Thériault, Mariem Ben Moussa, Marjorie Perron, Christine Desbiens, Brigitte Poirier, Éric Poirier, Dominique Leblanc, Claudya Morin, Julie Lemieux, Jean-Charles Hogue, Dominique Boudreau. Metaplastic carcinoma of the breast: A single-center 18-year series of 73 cases [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-12-03.

Sonographic and pathological features of metaplastic squamous cell carcinoma of the breast: a case series

ObjectiveThe aim of this study was to evaluate the sonographic features and to compare the sonographic findings with the pathologic features.MethodsThe sonographic and pathological features of all patients were retrospectively reviewed.ResultsAll these 9 patients presented with a palpable breast mass first found by the patient before presentation. The median diameters were 3.67 cm. On two-dimensional imaging, 8 masses showed mixed echogenicity with both solid and cystic components, and only 1 mass showed hypoechoic. All the masses had irregular shapes. 1 mass had indistinct margin and 8 masses had microlobulated margins. Calcifications was seen in 1 mass. On color Doppler flow imaging, 8 masses had high vascularity with high resistance index; 5 masses had grade III blood flow signal; 3 masses had grade II blood flow signal. On histopathological examination, 5 masses were adenocarcinoma with squamous metaplasia, and 4 masses were pure SCC. On immunohistochemical staining, estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor (HER2) were negative in 5 masses. There were 2 patients with lymph node metastasis.ConclusionsMost of the sonographic features of MSCC were mixed echogenicity with central cystic components, posterior echo enhancement, abundant vascularity with high resistance.

Metaplastic carcinoma of the breast: Clinicopathological features and treatment outcomes with long-term follow up.

Metaplastic breast carcinoma is an uncommon subtype of invasive ductal carcinoma with a tendency towards poorer clinical outcomes. Following ethical approval, the current study reviewed the institutional records of ~2,500 women with breast cancer. A total of 14 cases of metaplastic breast cancer were reviewed for management and treatment outcomes. The results demonstrated that patients had median follow up of 30 months, a 5-year disease-free survival of 57.1% and 5-year overall survival of 57.1%. The majority of patients had at least T2 disease and all tumours were high grade. Additionally, most patients were triple negative and nodal metastases were uncommon. Metaplastic breast cancer is an aggressive variant of invasive breast cancer. Most patients can be treated with breast conservation and survival parameters tend to be worse than more common breast cancer subtypes.

GATA binding protein 3 (GATA3) as a marker for metaplastic spindle cell carcinoma of the breast

Spindle cell lesions of the breast comprise a diverse set of tumors; harboring significant histological and immunohistochemical (IHC) overlap. Accurate diagnosis and classification of spindle cell lesions in the breast remains challenging, especially in core biopsies. In the current study, we evaluated a spectrum of spindle cell lesion of the breast with a panel of IHC antibodies in an effort to differentiate metaplastic spindle cell carcinoma from its benign and malignant mimickers. Our study included 92 patients who underwent breast core biopsies or breast resections at Northwell Health who were diagnosed with benign and malignant tumor/tumor-like spindle cell lesions. Tumors subtypes in this the study included: angiosarcoma, nodular fasciitis, fibromatosis, myofibroblastoma, phyllodes tumors (benign, borderline and malignant), primary sarcomas and metaplastic spindle cell carcinoma. Our biomarker panel included high molecular weight keratin (HMWK), CAM5.2, AE1/AE3, p63, CD34 and GATA3. GATA3 expression was significantly higher in metaplastic carcinomas (88.9 % vs 4.1 %, p < 0.001), when compared to other spindle cell lesions. The sensitivity and specificity for detecting metaplastic carcinomas reached 84.2 % and 97.3 %, respectively. Regarding cytokeratin panels, none of the three individual markers were as sensitive or specific for metaplastic breast carcinoma. GATA3 is the most specific and sensitive marker forfor the identification of metaplastic spindle cell carcinoma of the breast.

Abstract IA020: Mechanics, multinucleation, and EMT

Abstract Multinucleation is found in more than one third of tumors and is linked to increased tolerance for mutation, resistance to chemotherapy, and invasive potential. The integrity of the genome depends on proper execution of the cell cycle, which can be altered through mechanotransduction pathways as the tumor microenvironment stiffens during tumorigenesis. We recently found that inducers of epithelial-mesenchymal transition (EMT), including transforming growth factor-beta (TGFbeta), also promote multinucleation in stiff microenvironments through Snail-dependent expression of the filament-forming protein septin-6, resulting in midbody persistence, abscission failure, and multinucleation. Consistently, we observed elevated expression of Snail and septin-6 as well as multinucleation in a human patient sample of metaplastic carcinoma of the breast, a rare classification characterized by deposition of collagen fibers and active EMT. In contrast, a soft microenvironment protected mammary epithelial cells from becoming multinucleated by preventing Snail-induced upregulation of septin-6. I will describe data suggesting that tissue stiffening during tumorigenesis synergizes with oncogenic signaling to promote genomic abnormalities that drive cancer progression. Citation Format: Celeste M. Nelson. Mechanics, multinucleation, and EMT [abstract]. In: Proceedings of the AACR Virtual Special Conference on the Evolving Tumor Microenvironment in Cancer Progression: Mechanisms and Emerging Therapeutic Opportunities; in association with the Tumor Microenvironment (TME) Working Group; 2021 Jan 11-12. Philadelphia (PA): AACR; Cancer Res 2021;81(5 Suppl):Abstract nr IA020.

METAPLASTIC CARCINOMA OF BREAST

Metaplastic carcinoma of the breast is a rare but aggressive type of breast cancer that has been recognized as a unique pathologic entity by the World Health Organization. Morphologically, it is characterized by the differentiation of neoplastic epithelium into squamous cells and/or mesenchymal-looking elements (spindle cells, cartilage or bone, etc). It shares many similarities with invasive ductal carcinoma and benign lesions on mammography, which further complicates the diagnosis. Treatment for metaplastic breast carcinoma is relatively unknown because of the rarity of the disease, but studies suggest that removal of the tumor and adjuvant radiation therapy has the greatest benefit.