Triple Negative Carcinoma Research Articles

Abstract P4-03-09: Genetic and hereditary factors in breast cancer: Experience in a mastology service on analysis of genetic tests in high risk women

Abstract Background: Breast cancer is the most prevalent cancer in women in Brazil. The estimate by 2018 is 59,700 new cases. Of these, 10 to 15% are hereditary, caused by mutations in susceptibility genes that increase the risk of disease onset. These types of mutations can occur in several genes, each associated with different risks of developing the pathology. In hereditary breast-ovarian syndrome, the most frequently altered genes are BRCA1 and BRCA2. Mutations of these genes are associated with a 70-85% risk of developing breast cancer during life, but we know that there are other types of genetic alterations at risk of developing breast, ovarian, or other cancers - many are of uncertain significance and others, less known, appear to have high pathogenic potential. Thus, individuals identified with hereditary risk for developing breast or ovarian cancer should have intensive follow-up and genetic counseling. Materials and methods: A retrospective study was carried out between 2015 and 2018. The charts of each of the patients submitted to genetic counseling with a total of fifteen women were analyzed. Eleven of these, performed genetic tests to evaluate mutations in BRCA1 and 2, and four patients extended panels. Subsequently, a statistical analysis of the data was performed and the results were analyzed thanks to the informed consent that the patients signed. Results: Among the fifteen cases the age ranged from 27-68 years. Fifteen patients were analyzed, twelve with diagnosis of breast cancer and three without. In the eleven women who tested for BRCA1/2, 27% had mutations for these types of genes and three pathogenic variants of the genes. In the four who did the extended test, three had mutations in six types of genes, two with mutations of uncertain significance(VUS) and one pathogenic variant of the BLM gene. The indications for the exams were: 1)breast cancer patients: five cases with triple negative carcinomas and age less than 60 years-41.66%; 2)four with family history-33.33%; 3)three only by age-25%. In those without breast cancer the indications were family history. The majority of cases were requested for triple negative neoplasia, in which two cases presented mutation(40%) and three cases without mutation(60%), the two mutations in the BRCA1 and BRCA2 genes, one in each of them and none in VUS . In the four cases with a family history, two had mutations and two did not(50%) - two in BRCA 2 and one in VUS. In the three cases without cancer was found mutation in only one of them and with important family history was found mutation in one case(BRCA2). Conclusions: Mutations in BRCA1/2 genes are associated with susceptibility to develop breast-ovarian cancer. Currently these mutations are responsible for only a minority of familial cases and we also find variants of uncertain and pathogenic behavior. Intensive research to identify other types of genetic mutations that could be responsible for a significant percentage of breast cancer in BRCA1/2 negative families, as well as assessing their importance, appear to be necessary. As already published by other authors, although our casuistry is small, we also call attention to the presence of mutations in young patients with triple negative breast carcinomas. Citation Format: Chagas SR, Pineres MdRS, Chagas CR, Vieira RJ. Genetic and hereditary factors in breast cancer: Experience in a mastology service on analysis of genetic tests in high risk women [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-03-09.

Abstract P2-06-07: Investigating the role of focal adhesion kinase in regulating CSC activity in invasive ductal carcinoma

Abstract Background Breast Cancer Stem-like Cells (BCSCs) have been associated with tumour development, metastasis and recurrence1. Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase classically known for its role in metastasis, proliferation and survival. We have previously shown FAK plays a role in regulating CSC activity in DCIS2. We aimed to investigate FAK and CSC marker expression in a retrospective patient cohort. We aimed to evaluate the effects of FAK inhibition on CSC activity in Invasive Ductal Carcinoma. Methods Using a retrospective case-control cohort of 244 patients across a range of molecular phenotypes we evaluated FAK Immunohistochemical expression alongside CSC markers; Aldehyde Dehydrogenase 1 (ALDH1) and Integrin Alpha 6 (ITGa6). FAK expression was measured in IDC cell lines and ALDEFLUOR high expressing cells. FAK was inhibited using 0.5μM VS4718 or SiRNA and CSC activity evaluated in 5 cell lines and 25 patient samples. We determined the effects of 50mg/kg VS4718 for 4 weeks as single agent or in combination with Paclitaxel 7.5mg/kg in a ER-/PR-/HER- Patient Derived Xenograft model (PDX). Results Total FAK expression was associated with reduced breast cancer survival. Co-expression of FAK and either BCSC marker was associated with the poorest survival. FAK and CSC marker expression pFAKtFAKALDH1ITGα6tFAK and ALDH1tFAK and ITGα6Recurrence Risk0.58 (0.31-1.08) p = 0.0842.05 (1.23-3.43) p = 0.0062.21 (1.20-4.05) p=0.0111.54 (0.92-2.23) p=0.107 Breast Cancer Death0.41 (0.12-1.51) p=0.1824.84 (2.33 -10.04) p = <0.0016.58 (1.87-23.10) p=0.0032.23 (1.08-4.58) p=0.03016.7 (3.7-73.9) p=<0.00112.8 (1.37-13.2,) p=0.012Hazard ratios calculated using cox-proportional hazard regression analysis. pFAK was higher in ALDEFLUOR expressing cells and triple negative cell lines. SiRNA knockout of FAK reduced mammosphere formation, self-renewal and ALDEFLUOR expression from 1.2% to 0.2% (p=<0.01, unpaired t-test) in MDA-MB-231 cells. VS4718 reduced primary mammosphere forming efficiency in all cell lines and reduced self-renewal in ER negative cell lines. FAK inhibition led to a reduction in mammosphere forming efficiency and self-renewal in 25 primary breast cancer specimens as outlined below: FAK inhibition reduces MFE Primary Breast Cancer samples ER negative cell lines ER+/PR+/ Her2-ER-/PR-/Her2+ER-/PR-/Her2-SKBr3MDA-MB-231SUM159Primary mammosphere formation51.1% (n=17)53.2% (n=4)49.6% (n=5)74.1%84.8%67.6%Secondary mammosphere formation45.8% (n=8) 43.9% (n=3)42.1%57.9%47.5%Percentage of mammospheres formed given relative to control. Cell line work, minimum n=6. All above significant p=<0.05, One way Anova used with post hoc Tukeys test. VS4718 reduced tumour growth, Ki67 staining and CSC activity in our triple negative PDX model. VS4718 administration reduced ex-vivo mammosphere formation, tumour initiating capacity and prevented ALDEFLUOR enrichment when used in combination with Paclitaxel. Conclusions FAK, ALDH1 and ITGa6 are associated with increased breast cancer mortality in early breast cancer. Inhibition of FAK reduces CSC activity in vitro and in vivo in cell lines and patient samples. This data suggest that FAK inhibition may be used to reduce CSC activity in triple negative carcinoma. 1. Williams et al, Stem cells 2015. Citation Format: Timbrell S, Aglan H, Cramer A, Foden P, Weaver D, Pachter J, Farnie G, Clarke R, Bundred N. Investigating the role of focal adhesion kinase in regulating CSC activity in invasive ductal carcinoma [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-07.

GATA3 expression has an opposite prognostic value in luminal and triple-negative feline invasive mammary carcinomas

GATA3 expression has an opposite prognostic value in luminal and triple-negative feline invasive mammary carcinomas

Eccrine ductal and acrosyringeal metaplasia in breast carcinomas: report of eight cases.

Eccrine ductal and acrosyringeal metaplasia was described in 2006 as the presence of tumor structures that resemble the epithelium of the eccrine skin ducts and their opening within the epidermis, the acrosyringeum. Here, we report the clinical, morphological, and phenotypic characteristics of eight breast carcinomas that we collected over the past years showing this metaplasia. Unlike squamous metaplasia, acrosyringeal and eccrine ductal metaplasia are luminated structures comprising cells with eosinophilic cytoplasm that are easily detectable in routine histological slides. These lesions invariably appeared in triple-negative carcinomas, but the cases differed in their clinical, radiological, and histological manifestations. Correct interpretation of these changes may facilitate identification of some metaplastic carcinomas.

SRC inhibition prevents P-cadherin mediated signaling and function in basal-like breast cancer cells

BackgroundBasal-like breast cancer (BLBC) is a poor prognosis subgroup of triple-negative carcinomas that still lack specific target therapies and accurate biomarkers for treatment selection. P-cadherin is frequently overexpressed in these tumors, promoting cell invasion, stem cell activity and tumorigenesis by the activation of Src-Family kinase (SRC) signaling. Therefore, our aim was to evaluate if the treatment of BLBC cells with dasatinib, the FDA approved SRC inhibitor, would impact on P-cadherin induced tumor aggressive behavior.MethodsP-cadherin and SRC expression was evaluated in a series of invasive Breast Cancer and contingency tables and chi-square tests were performed. Cell-cell adhesion measurements were performed by Atomic Force Microscopy, where frequency histograms and Gaussian curves were applied. 2D and 3D cell migration and invasion, proteases secretion and self-renew potential were evaluated in vitro. Student’s t-tests were used to determine statistically significant differences. The cadherin/catenin complex interactions were evaluated by in situ proximity-ligation assay, and statistically significant results were determined by using Mann-Whitney test with a Bonferroni correction. In vivo xenograft mouse models were used to evaluate the impact of dasatinib on tumor growth and survival. ANOVA test was used to evaluate the differences in tumor size, considering a confidence interval of 95%. Survival curves were estimated by the Kaplan-Meier’s method, using the log-rank test to assess significant differences for mice overall survival.ResultsOur data demonstrated that P-cadherin overexpression is significantly associated with SRC activation in breast cancer cells, which was also validated in a large series of primary tumor samples. SRC activity suppression with dasatinib significantly prevented the in vitro functional effects of P-cadherin overexpressing cells, as well as their in vivo tumorigenic and metastatic ability, by increasing mice overall survival. Mechanistically, SRC inhibition affects P-cadherin downstream signaling, rescues the E-cadherin/p120-catenin complex to the cell membrane, recovering cell-cell adhesion function.ConclusionsIn conclusion our findings show that targeting P-cadherin/SRC signaling and functional activity may open novel therapeutic opportunities for highly aggressive and poor prognostic basal-like breast cancer.

An Update on Breast Cancer Multigene Prognostic Tests—Emergent Clinical Biomarkers

Multigene signatures generate crucial prognostic information particularly useful for cancer patients where clinical parameters and traditional immunohistochemical markers alone lead to equivocal prognosis. Clinicians are now provided with molecular tools that assist in the outline of adjuvant therapies, namely helping decide on the extension of adjuvant endocrine therapy or on suppressing adjuvant chemotherapy in patients were toxic effects are particularly deleterious or when this treatment is fundamentally not needed. The importance of cancer multigene prognostic signatures is well elucidated in the guidelines for adjuvant systemic therapy in early-stage breast cancer and the guidelines on disease staging that are progressively integrating gene expression assays as classification biomarkers. In addition to the predictive and prognostic value, some genetic tests provide intrinsic subtyping classification. Herewith, we compare the molecular tests OncotypeDX, MammaPrint, Prosigna, EndoPredict, Breast Cancer Index, Mammostrat, and IHC4 and report the eligibility of each one in the suitable setting. Through to now, there is not a commercially available multigene test that makes recommendations regarding adjuvant treatment for HER-2 and triple negative breast cancers. Thus, these patients still receive adjuvant chemotherapy. Importantly, triple negative carcinomas are very heterogeneous regarding prognosis and new molecular signatures that decipher this very heterogeneous subgroup of breast cancer may improve the clinical management of the disease.

Rare morphological appearance of breast carcinoma

Clinical question This is a case of an elderly woman who presented symptomatically and on examination was found to have a multifocal breast cancer. An ultrasound-guided axillary node biopsy was...

Abstract 5118: Development of new alternative in vivo models to study early metastasic dissemination in breast cancer

Abstract Breast cancer is the first cause of death from female cancer. After the treatments against the primary tumor, a few cells can prevail in a state of quiescence for a long period of time, becoming minimal residual disease. There is a clear need for alternative techniques to enable an early detection of the disease for a better understanding of it and the generation of therapies capable of acting with a smaller tumor burden. Although many models have been developed for the detection of macrometastasis, there is a limitation of in vivo models that allow the identification of disseminated cells, micrometastasis, or analyze another steps of the metastasic cascade, as embolization or cell arrest. The aim of this work is the generation of in vivo models to enable the detection of disseminated tumor cells (DTCs) We began our study by evaluating the presence of disseminated tumor cells in three in vivo models and quantification by FACS. To this end, we generated the F3II murine triple negative mammary carcinoma line expressing the fluorescent protein GFP (F3II GFP); the F3II line was used as control. In s.c heterotopic model, we observed the presence of positive cells in tumors and livers of mice inoculated with F3II GFP (Student's t test) 30 days post inoculation. In the s.c orthotopic model, we detected positive cells in tumors of mice inoculated with F3II GFP (Student's t test). In both models, we did not observe significant differences in the presence of lung DTCs. In experimental metastasis models, we detected DTCs 15 days post inoculation in lungs of mice injected i.v with F3II GFP (Mann Whitney test).We carried out the search for cells disseminated at 24 h in order to obtain an in vivo model that evaluates the establishment capacity of these cells, and we observed that the percentage of GFP positive cells was higher in those mice inoculated iv with F3II GFP (Student´s t test). In addition, the presence of DTCs was detected by fluorescence microscopy in blood smears of these mice, suggesting that at 24 h there are fluorescent tumor cells in both lung and blood. In conclusion, although the established models allowed us to detect DTCs, the experimental metastasis model was more efficient in the detection and quantification of disseminated tumor cells. These models allows the detection and quantification of DTCs in the lung and blood circulation within 24 hours and 15 days after inoculation and could be used to study the mechanisms of metastasic dissemination involved in these cells and to test the capacity of various anti-tumor drugs to the early stage of metastasis Citation Format: Johanna Elena Sidabra, Carla Sabrina Capobianco, Maria Florencia Gottardo, Daniel Fernando Alonso, Hernan Gabriel Farina. Development of new alternative in vivo models to study early metastasic dissemination in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5118.

Management and prognosis of pure primary squamous cell carcinoma of the breast

PurposeThe aim of the study was to investigate the management and prognosis of Pure primary squamous cell carcinoma (PPSCC) of the breast. Materials and methodsThis study is a multicentre retrospective cohort from three French tertiary referral hospitals (Rennes, Orléans and Tours) including all women treated for a PPSCC of the breast defined by squamous cells that could contain a minority of sarcomatoid component. We excluded carcinomas with a ductual component. Clinicopathologic, radiological and therapeutic patterns were described. Demographic, histological and therapeutic characteristics were compared to a population of women with triple negative invasive breast carcinomas. ResultsTwelve patients were included, with a mean age of 71.6 years. All lesions were unifocal, with a cystic complex ultrasound mass in 50% of cases. Mean tumor size was 43mm, with axillary lymph node metastasis in 25% of patients.The comparison with a population of women with triple negative breast carcinomas revealed that women with PPSCC were older (71 versus 57 years, p=0.003), tumor size was larger (43mm versus 25mm, p=0.032) and local recurrence occurred earlier (three months versus 38 months, p=0.014). ConclusionPPSCC is a rare entity with a worse prognosis in comparison with triple negative invasive carcinoma.

Comparison of triple negative (TN) and HER2 positive (HER2+) invasive lobular carcinomas (ILCs) to a matched cohort of invasive ductal carcinomas.

e13088Background: Most ILCs are estrogen receptor (ER) positive and tend to relapse at different sites than IDCs, suggesting distinct biology. We explored prognosis for TN and HER2+ ILCs and IDCs. Methods: From the prospective British Columbia (BC) Cancer Outcomes Unit database, we identified TN and HER2+ ILCs diagnosed 01/2003 to 12/2013 referred to BC Cancer. Exclusions: stage IV, mixed ILC/IDC, unknown HER2, and prior / subsequent breast cancer. ILCs were propensity-score matched (1:2) to IDCs for age, T/N stage, biomarkers, grade, chemotherapy (CT), and nodal radiation (RT). Kaplan-Meier method was used to estimate relapse-free survival (RFS) and overall survival (OS). Results: Of 2925 ILCs diagnosed, 2587 were referred, and 143 were TN or HER2+. By comparison, there were 5526 TN and HER2+ IDCs. After exclusions, 127 TN and HER2+ cases (23% TN; 77% HER2+) were matched as shown in Table 1. Five-year RFS was ILCs 81% (95% confidence interval [CI], 73-87%) and IDCs 84% (95% CI, 79-88%). Five-year OS was ...

Triple Negative Apocrine Carcinomas as a Distinct Subtype of Triple Negative Breast Cancer: A Case-control Study

BackgroundInvasive triple negative apocrine carcinoma (TNAC) of the breast is a rare type of triple negative breast cancer. Several studies reported significantly distinct prognosis for TNAC when compared with most of the non-apocrine triple negative (NATN) tumors. This is a case-control study reporting onoutcomes from our long-term single-center experience. Patients and MethodsWe analyzed the clinicopathologic features of a series of 46 TNAC tumors treated in a 15-year period. Tumor characteristics and outcomes have been compared with a homogeneous control series of 43 NATN tumors treated during the same follow-up period. Local relapse-free survival (LRFS), distant metastases-free survival (DMFS), and overall survival (OS) have been evaluated. ResultsLRFS in the TNAC group was 85% and 78% at 5 and 10 years, respectively. LRFS in the NATN group was 90% and 79% at 5 and 10 years, respectively (hazard ratio [HR], 1.14; 95% confidence interval [CI], 0.41-3.19; P = .80). DMFS in the TNAC group was 85% and 85% at 5 and 10 years, respectively. DMFS in the NATN group was 85% and 75% at 5 and 10 years, respectively (HR, 0.39; 95% CI, 0.14-1.08; P = .071). OS in the TNAC group was 86% and 83% at 5 and 10 years, respectively. OS in the NATN group was 86% and 63% at 5 and 10 years, respectively. OS was significantly better in the TNAC group (HR, 0.45; 95% CI, 0.20-0.99; P = .049). ConclusionsTNAC seems to represent a distinct group of triple negative breast cancer, characterized by a favorable long-term outcome when compared with NATN tumors.

Prostate-specific membrane antigen in breast cancer: a comprehensive evaluation of expression and a case report of radionuclide therapy.

Prostate-specific membrane antigen (PSMA), a protein product of the folate hydrolase 1 (FOLH1) gene, is gaining increasing acceptance as a target for positron emission tomography/computer tomography (PET/CT) imaging in patients with several cancer types, including breast cancer. So far, PSMA expression in breast cancer endothelia has not been sufficiently characterized. This study comprised 315 cases of invasive carcinoma of no special type (NST) and lobular breast cancer (median follow-up time 9.0years). PSMA expression on tumor endothelia was detected by immunohistochemistry. Further, vascular mRNA expression of the FOLH1 gene (PSMA) was investigated in a cohort of patients with invasive breast cancer provided by The Cancer Genome Atlas (TCGA). Sixty percent of breast cancer cases exhibited PSMA-positive endothelia with higher expression rates in tumors of higher grade, NST subtype with Her2-positivity, and lack of hormone receptors. These findings were confirmed on mRNA expression levels. The highest PSMA rates were observed in triple-negative carcinomas (4.5×higher than in other tumors). Further, a case of a patient with metastatic breast cancer showing PSMA expression in PET/CT imaging and undergoing PSMA radionuclide therapy is discussed in detail. This study provides a rationale for the further development of PSMA-targeted imaging in breast cancer, especially in triple-negative tumors.

Abstract P6-09-07: Triple negative apocrine carcinomas as a distinct subtype of triple negative breast cancer: A case-control study

Abstract Introduction. Invasive apocrine carcinoma of the breast is a rare type of breast cancer (BC), pure apocrine carcinoma constitutes <1% of all BC. Mammary apocrine epithelium has a characteristic steroid receptor profile that is negative for full length estrogen receptor-alpha and progesterone receptor and is androgen receptor positive. Conflicting data are available on the outcome of this type of disease: few studies reported significantly different prognosis of triple negative (TN) apocrine carcinomas when compared to most non-apocrine triple negative (NA-TN) tumors. The aim of this study is to report our long-term experience in a single-center series of TN apocrine tumors. Methods. We analyzed clinical and pathological features of a series of TN apocrine carcinomas treated at our Centre in a 15-year period. Clinical and pathological characteristics and outcomes have been compared with a control series of NA-TN tumors treated during the same follow up period. Local relapse-free survival (LRFS), distant metastases-free survival (DMFS), and overall survival (OS) have been evaluated and compared between groups of patients. Results. Forty-five TN apocrine carcinomas were analyzed. The mean age at diagnosis was 60 years (range 34-83 years). The proportions of apocrine tumor grades varied, with G1 being seen in 6.8% of patients, G2 in 51.1%, and G3 in 40.1%. The majority of apocrine carcinomas had small tumor size (T1: 72.7%; T2: 27.3%), and negative axillary nodal status (66.7%). The series was compared to a homogenous control group of 45 NA-TN patients. The mean age was 54 years (range 32-79 years), affected by high grade (G3: 53.7%), small tumor size (T1: 87.5%; T2: 12.5%), and mostly negative axillary nodal status (82.9%). LRFS in the apocrine group was 85% and 78% at 5- and 10-year, respectively. LRFS in the NA-TN group was 90% and 79% at 5- and 10-year, respectively. No difference was evidenced between groups (HR 1.44 95%CI 0.62-3.79; p=0.39). DMFS in the apocrine group was 85% and 85% at 5- and 10-years, respectively. DMFS in the NA-TN group was 85% and 75% at 5- and 10-year, respectively. DMFS was significantly better in the apocrine group (HR 0.69 95%CI 0.28-1.62). OS in the apocrine group was 86% and 83% at 5- and 10-year, respectively. OS in the NA-TN group was 86% and 63% at 5- and 10-years, respectively. OS was significantly better in the apocrine group (HR 0.57 95%CI 0.26-1.18). Conclusions. Apocrine carcinomas represent a clinic-pathological distinct group of triple-negative BC, characterized by significantly more favorable clinical prognosis in terms of long-term disease-related morbidity or mortality when compared to NA-TN tumors. Citation Format: Meattini I, Pezzulla D, Carta GA, Becherini C, Perna M, Grassi R, Garlatti P, Desideri I, Scotti V, Bernini M, Sanchez LJ, Orzalesi L, Nori J, Bianchi S, Livi L. Triple negative apocrine carcinomas as a distinct subtype of triple negative breast cancer: A case-control study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-07.

Genomic profiling of metaplastic breast carcinomas reveals genetic heterogeneity and relationship to ductal carcinoma

Metaplastic breast carcinomas comprise a histologically heterogenous group of tumors. Although most are triple (estrogen/progesterone receptor, HER2) negative, these rare tumors are clinicopathologically distinct from other triple negative carcinomas and may be aggressive with worse chemotherapy responses. On the other hand, metaplastic carcinomas are histologically diverse, which is reflected in gene expression differences among subtypes. Whether metaplastic carcinomas are genetically distinct from other triple negative cancers and whether genetic differences underlie histologic subtypes remains poorly understood. We sequenced 408 cancer-related genes in 28 metaplastic carcinomas, including chondroid matrix-producing carcinomas (n = 10), spindle cell carcinomas (n = 5), and carcinomas with squamous (n = 5), mixed spindle/squamous (n = 5), and mixed metaplastic (n = 3) differentiation. Metaplastic carcinomas were highly enriched for PIK3CA/PIK3R1 (61%) and Ras-Map kinase (25%) pathway aberrations compared to other triple negative carcinomas (TCGA dataset 14%, p < 0.001 and 7%, p = 0.005, respectively) and harbored a high frequency of TP53 (64%) and TERT promoter (25%) mutations, but this varied among subtypes. Chondroid-matrix producing carcinomas lacked PI-3 kinase and Ras-Map kinase aberrations and TERT promoter mutations, compared to 100%, 39%, and 39% of non-matrix-producing tumors, respectively. TERT promoter mutations were enriched (47%) in spindle cell carcinomas and tumors with squamous or spindle/squamous differentiation. Spindle cell carcinomas lacked TP53 mutations, in contrast to other subtypes (78%, p = 0.003). Separate analysis of paired ductal carcinoma in situ and metaplastic carcinoma revealed shared clonality in all cases (n = 8). Activating PI-3 kinase and Ras pathway mutations were early events, and inactivating mutations in tumor suppressors including RB1, CDKN2A, and TP53 were associated with invasion in individual cases. Metaplastic components of two tumors showed genetic progression from separately sequenced paired invasive ductal carcinoma. The findings suggest that metaplastic carcinomas are genetically distinct from other triple negative breast cancers and highlight genetic heterogeneity that broadly correlates with histologic subtype. Heterologous elements progress from associated ductal carcinoma.

Primary Squamous Cell Carcinoma of Breast in a Young Female: An Institutional Experience with Review of Literature

Invasive or infiltrating ductal carcinoma is the most common type of breast cancer while primary squamous cell carcinoma of breast is extremely rare occurring in 0.04%-0.1% of all breast cancer cases known for aggressive behaviour and poor prognosis. We hereby report a case of primary squamous cell carcinoma of breast in a 31-yearold female who presented with a left breast lump of 2 months duration. Lumpectomy done at another non-oncology centre showed invasive ductal carcinoma with margin positivity for which she underwent modified radical mastectomy at our institute. Post-operative immune-histopathology revealed triple negative squamous cell carcinoma. Her metastatic work-up with whole-body positron emission tomography scan was negative. She was treated with adjuvant chemotherapy doxorubicin, cyclophosphamide and docetaxel followed by loco-regional radiotherapy to left chest wall which she tolerated well. No hormonal therapy was given in view of hormone receptor negativity. She is presently on follow-up for more than 6 months without any evidence of recurrence or distant metastasis. This case is being presented to highlight its extreme rarity, it’s occurrence in a young female, the diagnostic and therapeutic challenges it presented and the overall prognosis of this neoplasm.

Canine invasive mammary carcinomas as models of human breast cancer. Part 2: immunophenotypes and prognostic significance

PurposeRelevant animal models of human breast cancer are currently needed, especially for the aggressive triple-negative breast cancer subtype. Recent studies and our results (Part 1) indicate that spontaneous canine invasive mammary carcinomas (CMCs) resemble human breast cancer by clinics and pathology as well as behavior and prognostic indicators. We hypothesized that the current molecular classifications of human breast cancer, used for therapeutic decision, could be relevant to dogs.MethodsThree hundred and fifty female dogs with spontaneous CMC and a 2-year follow-up were retrospectively included. By immunohistochemistry, CMCs were classified according to Nielsen (Clin Cancer Res 10:5367–5374, 2004) and Blows (PlosOne doi: 10.1371/journal.pmed.1000279, 2010) into the subtypes of human breast cancer.ResultsFour immunophenotypes were defined either according to Nielsen classification (luminal A 14.3%, luminal B 9.4%, triple-negative basal-like 58.6%, and triple-negative nonbasal-like 17.7% CMCs); or to Blows classification (luminal 1−: 11.4%, luminal 1+: 12.3%, Core basal phenotype: 58.6%, and five-negative phenotype: 17.7%). No HER2-overexpressing CMC as defined by a 3 + immunohistochemical score was observed in our cohort. By univariate and multivariate analyses, both immunophenotypical classifications applied to CMCs showed strong prognostic significance: luminal A or luminal 1+ CMCs showed a significantly longer disease-free interval (HR = 0.46), Overall (HR = 0.47), and Specific Survival (HR = 0.56) compared to triple-negative carcinomas, after adjustment for stage.ConclusionsIn our cohort, triple-negative CMCs largely predominated (76%), were much more prevalent than in human beings, and showed an aggressive natural behavior after mastectomy. Dogs are thus potent valuable spontaneous models to test new therapeutic strategies for this particular subtype of breast cancer.

Evaluation of anatomic and prognostic stages of breast cancer according to the 8th edition of the TNM staging system - Retrospective analysis based on data from deceased patients once diagnosed with breast cancer

The 8th edition of the Tumor-Node-Metastasis (TNM) based staging of breast cancer introduces a prognostic stage influenced by biomarkers along the traditional T, N and M categories. To retrospectively assess stage influencing prognostic variables; and the anatomic and prognostic stages on the basis of the overall survival (OS) of a cohort of deceased patients once diagnosed with breast cancer. We included patients with known causes of death certified at the Bács-Kiskun County Teaching Hospital and having a history of breast cancer diagnosed on a resection specimen at the same institution. Prognostic factors were obtained from the histopathological reports. Statistics included one-way ANOVA, Dunn's post hoc test and Kaplan-Meier curve analyses. The 303 patients grouped as breast cancer related death (n = 168) or unrelated (n = 135) showed significant differences in most stage defining prognostic factors and the anatomic and prognostic stages. Significant differences in 5-year OS were observed between pT and pN categories, histological grades and estrogen receptor statuses. Except for stages I and II, significant differences were found between both different anatomic and prognostic stages (p<0.001). Stage IV is by definition uniform, but we identified survival differences between biomarker based subgroups: triple negative carcinomas had worse OS than estrogen receptor positive and HER2 negative carcinomas. Our analysis based on real survival data suggests that the prognostic stages separate patients according to OS similarly to the anatomic stages. The results validate the prognostic stages, but also suggest that separating stage IV disease according to biomarkers makes sense. Orv Hetil. 2017; 158(35): 1373-1381.

Abstract 607: PDL1 expression associated with triple negative breast ductal carcinomas in African American women

Abstract Background: Tumor cells avoid host immune response through expression of inhibitory T cell regulator, Programmed cell death ligand (PDL1).Our objective was to evaluate PDL1 expression by immunohistochemistry in the four major subtypes of breast carcinoma (Luminal A, Luminal B, HER2, and Triple Negative) in a population of 202 African-American (AA) women with other clinicopathological factors. Design: Tissue microarrays (TMAs) were constructed from FFPE tumor blocks from primary ductal breast carcinomas in 202 African-American females. Two separate 1 mm cores represented each case. Five micrometer sections were stained with rabbit monoclonal antibody against PDL1. The sections were evaluated for the percentage and intensity of membrane staining in both tumor and immune cells. Cut off was &amp;gt; 1%. Bivariate analysis was done via χ2 analysis and survivability data was calculated via the generation of Kaplan-Meier curves (SPSS v19). Statistical significance was assumed if p &amp;lt; 0.05. Results: PDL1 expression in only tumor cells, only immune cells and in combination was associated with ER negative (p&amp;lt;0.0001), PR negative (p&amp;lt;0.0001), Triple negative subtype (p&amp;lt;0.0001) and high grade (p&amp;lt;0.0001) breast ductal cancers. Conclusion: Our study finding of selective expression of PDL1 in triple negative breast ductal cancers (TNBC) in AA women suggests that inhibition of adaptive immune response is involved in the progression of these cancers. PDL1/PD1 is the inhibitory check point of immune response resulting in decreased T cell activation and cytokine production. Some studies have shown that PDL1 expression is associated with loss of PTEN and phosphatide inositol 3 kinase pathway (PI3K) activation. Our previous study showed loss of PTEN in TNBC. Combining PDL1 inhibitors with PI3K inhibitors may be useful therapy for aggressive TNBC. Citation Format: Farhan Khan, Yasmine Kanaan, Luisel J. Ricks-Santi, Rabia Zafar, Hagos Aymut, Tammey Naab. PDL1 expression associated with triple negative breast ductal carcinomas in African American women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 607. doi:10.1158/1538-7445.AM2017-607

Breast cancer biomarkers at Niger delta university hospital: Comparisons with national and international trends and clinical significance

Breast cancer biology is heterogeneous and patients with the same diagnostic profile have markedly different clinical outcomes. Gene expression profiling and its surrogate IHC markers classified breast cancer into four molecular subtypes with different prognosis, targeted therapies, and/or clinical outcomes. The present study was conducted to investigate breast cancer subtypes among women in NDUTH Bayelsa state and compared them with similar studies in other populations of international and national origin. Archived formalin fixed paraffin embedded tissue blocks were retrieved from January 2010-December 2014 provided 20 cases of microscopically confirmed invasive ductal breast carcinoma that were evaluable for histology and IHC (ER, PR, HER2, and Cytokeratin 5/6) immunostain. All the patients were females and most of them were under 50 years at presentation. The molecular subtypes were luminal A (54.1%), luminal B (25.0%), HER2 (12.5%), basal-like (4.2%), and unclassified (4.2%). Triple negative carcinoma (basal-like and unclassified combined) was 4.2%, ER+ (65%) and (PR+70%).Breast carcinoma in Bayelsa state women presents at a younger age. We note that the prevalence of the molecular subtypes of breast carcinoma appears to have variation in geographical distribution. The reasons for these differences could be technical, quality of fixation and processing, varying staining techniques, and different criteria in scoring and reporting. This study indicates that the majority of breast cancer in NDUTH lies at the two ends of the molecular spectrum, that is, luminal A (54.1%), sensitive to hormonal therapy and with a good prognosis, and “triple negative” (4.2%) not hormonally sensitive and with a poor prognosis.

P-cadherin: a useful biomarker for axillary-based breast cancer decisions in the clinical practice

Axillary lymph node metastases represent the most powerful breast cancer prognostic factor, dictating disease staging and clinical therapeutic decisions. Nonetheless, breast cancer patients with positive lymph nodes still exhibit a heterogeneous behavior regarding disease progression. Stem-like subpopulations of cancer cells show high migratory and metastatic capacity, thus we hypothesize that breast cancer stem cell markers evaluation in metastasized lymph nodes could provide a more accurate prediction of patient's prognosis. Therefore, the expression profile of P-cadherin, CD44, and CD49f, which have been already associated to stem cell properties in breast cancer, has been evaluated by immunohistochemistry in a series of 135 primary tumors and matched axillary lymph node metastases from 135 breast cancer patients. Taking in consideration the expression of the stem cell markers only in axillary nodes, P-cadherin was the only biomarker significantly associated with poor disease-free and overall patient's survival. Moreover, although a concordant expression between primary tumors and matched lymph nodes has been found in the majority of the cases, a small but significant percentage displayed divergent expression (18.2–26.2%). Remarkably, although CD44 and CD49f changes between primary tumors and lymph node metastasis did not impact survival, the cases that were positive for P-cadherin in lymph node metastases being negative in the primary tumor, presented the worst disease-free and overall survival of the whole series. Accordingly, negative cases for this marker in the lymph nodes with positive expression in the matched breast carcinoma demonstrated a better prognosis, which overlapped with tumors that were negative in both sites. P-cadherin and CD49f gain of expression was mainly found in triple-negative carcinomas. Our results indicate for the first time that the evaluation of P-cadherin expression in lymph node metastases is an important predictor of disease outcome, being a putative valuable marker for axillary-based breast cancer decisions in the clinical practice.