Subtypes In Inflammatory Breast Cancer Research Articles

Abstract PO1-14-10: Comprehensive clinicogenomic characterization of inflammatory breast cancer

Abstract BACKGROUND: Inflammatory breast cancer (IBC) is a rare type of breast cancer associated with a unique clinical presentation and overall poor outcomes, recognized as a distinct category by the AJCC staging system. The biological mechanisms driving the IBC phenotype are relatively undefined—partially due to a lack of comprehensive, large-scale genomic studies and limited clinical cohorts. Here, we report one of the largest, subtype-informed clinicogenomic characterizations of IBC to date. METHODS: A retrospective analysis of 2457 patients with metastatic breast cancer who underwent targeted tumor-only DNA-sequencing (OncoPanel, up to 447 cancer-associated genes) was performed at Dana-Farber Cancer Institute. Clinicopathologic, single nucleotide variant (SNV), copy number variant (CNV) and tumor mutational burden (TMB) comparisons were made between IBC and non-IBC cases. Median follow-up was 28.1 months. RESULTS: Our profiled cohort included 140 patients with IBC specimens (n = 68 primary tumors, 72 metastatic tumors) and 2317 patients with non-IBC specimens (n = 702 primaries, 65 local recurrences, 1550 metastases). Of these, 87.4% of patients were White, 4.7% Black, 3.6% Asian or Pacific Islander, and 4.3% other/unknown. Clinicopathologic differences between IBC and non-IBC cases were consistent with previous reports—including younger age at diagnosis of metastatic disease (51 vs 54 years, p = 0.04), and a higher proportion of grade 3, estrogen receptor-negative and HER2-positive tumors (p < 0.001). Among the hormone-receptor (HR)-positive subtype, IBC tumors showed a significant enrichment in Luminal B (LumB)-inferred disease (62.5% vs 39.8%, p < 0.005), defined as tumors with grade 3 or progesterone receptor staining < 10%. The most recurrent somatic alterations spanning all subtypes in IBC were TP53 (72%), ERBB2 (32%), PIK3CA (24%), CCND1 (12%), MYC (9%), FGFR1 (8%) and GATA3 (8%). A multivariate logistic regression analysis accounting for HR and HER2 status revealed a significant enrichment in TP53 SNVs in IBC vs non-IBC (OR 2.08 [95% CI 1.34-3.24], adjusted p-value 0.04). Frequency of TP53 alterations in IBC vs non-IBC cases was 85.1% vs 64.3% in HER2-positive and 50.0% vs 27.7% in HR-positive disease—with an enrichment of TP53 mutations in IBC LumB-inferred tumors vs non-LumB (64% vs 26%, p < 0.05). When comparing HR+ IBC LumB vs HR+ non-IBC LumB cases, TP53 mutations were again enriched (p < 0.05)—suggesting LumB-like histopathology is not the only driving feature of TP53 enrichment in HR+ IBC. TMB did not differ substantially between IBC and non-IBC and no other statistically significant enrichments were observed, including when grouping mutations into six canonical cancer pathways (cell cycle, Notch signaling, PI3K pathway, RTK/RAS signaling, TP53 pathway and WNT signaling). CONCLUSIONS: Taken together, this study provides a comprehensive landscape of somatic alterations in a large cohort of patients with metastatic IBC and non-IBC. Our data support a lack of major genomic differences other than enrichments in TP53 mutations and an associated LumB-like histopathology. These results both reinforce the importance of TP53 mutations in IBC biology and suggest additional analyses beyond somatic DNA-level changes are warranted. Future efforts with the DFCI IBC cohort will assess germline-somatic interactions, non-genomic or transcriptomic characterizations, and potential environmental influences to better understand the mechanisms driving this unique disease. Citation Format: Nolan Priedigkeit, Beth Harrison, Melissa Hughes, Robert Shue, Yvonne Li, Gregory Kirkner, Claire Remolano, Sarah Strauss, Janet Files, Anne-Marie Feeney, Ayesha Mohammed-Abreu, Ana Garrido-Castro, Romualdo Barroso-Sousa, Brittany Bychkovsky, Faina Nakhlis, Jennifer Bellon, Tari King, Bruce Johnson, Lynette Sholl, Deborah Dillon, Beth Overmoyer, Sara Tolaney, Andrew Cherniack, Nancy Lin, Filipa Lynce. Comprehensive clinicogenomic characterization of inflammatory breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-14-10.

Copy Number Variation in Inflammatory Breast Cancer.

Identification of a unique genomic biomarker in de novo inflammatory breast cancer (IBC) may provide an insight into the biology of this aggressive disease. The goal of our study was to elucidate biomarkers associated with IBC. We examined breast biopsies collected from Dana-Farber Cancer Institute patients with IBC prior to initiating preoperative systemic treatment (30 samples were examined, of which 14 were eligible). Patients without available biopsies (n = 1), with insufficient tumor epithelial cells (n = 10), or insufficient DNA yield (n = 5) were excluded from the analysis. Molecular subtype and tumor grade were abstracted from a medical records' review. Ten IBC tumors were estrogen-receptor-positive (ER+) and human epidermal growth factor receptor 2 (HER2)-negative (n = 10 out of 14). Sufficient RNA and DNA were simultaneously extracted from 14 biopsy specimens using the Qiagen AllPrep Kit. RNA was amplified using the Sensation kit and profiled using the Affymetrix Human Transcriptome Array 2.0. DNA was profiled for genome-wide copy number variation (CNV) using the Affymetrix OncoScan Array and analyzed using the Nexus Chromosome Analysis Suite. Among the 14 eligible samples, we first confirmed biological concordance and quality control metrics using replicates and gene expression data. Second, we examined CNVs and gene expression change by IBC subtype. We identified significant CNVs in IBC patients after adjusting for multiple comparisons. Next, to assess whether the CNVs were unique to IBC, we compared the IBC CNV data to fresh-frozen non-IBC CNV data from The Cancer Genome Atlas (n = 388). On chromosome 7p11.2, we identified significant CN gain located at position 58,019,983-58,025,423 in 8 ER+ IBC samples compared to 338 non-IBC ER+ samples (region length: 5440 bp gain and 69,039 bp, False Discovery Rate (FDR) p-value = 3.12 × 10-10) and at position 57,950,944-58,025,423 in 3 TN-IBC samples compared to 50 non-IBC TN samples (74,479 base pair, gain, FDR p-value = 4.27 × 10-5; near the EGFR gene). We also observed significant CN loss on chromosome 21, located at position 9,648,315-9,764,385 (p-value = 4.27 × 10-5). Secondarily, differential gene expression in IBC patients with 7p11.2 CN gain compared to SUM149 were explored after FDR correction for multiple testing (p-value = 0.0016), but the results should be interpreted with caution due to the small sample size. Finally, the data presented are hypothesis-generating. Validation of CNVs that contribute to the unique presentation and biological features associated with IBC in larger datasets may lead to the optimization of treatment strategies.

Abstract P4-06-09: A phase 1b study of neratinib with THP in metastatic and locally advanced breast cancer, and phase II study of THP followed by AC in HER2 + primary inflammatory breast cancer (IBC), and neratinib with taxol followed by AC in HR+/HER2- IBC

Abstract Background: The pathologic complete response (pCR) rate in inflammatory breast cancer (IBC) patients is worse than in non-IBC patients; new drug combinations are warranted to improve pCR rates across all IBC molecular subtypes. Based on our preclinical data, we added neratinib to standard neoadjuvant chemotherapy in both HER2+ (synergy) and HER2-/hormone receptor (HR)+ (high frequency of ERBB2 mut) untreated IBC, as a single-center, non-randomized phase I/II trial. Patients and Method: This study enrolled three cohorts: Cohort I phase Ib (C1P1B), Cohort I Phase II (C1P2) and Cohort II (C2). In C1P1B to determine the recommended phase 2 dose (RP2D), we enrolled patients with HER2+ metastatic or locally advanced breast cancer. Patients received paclitaxel/trastuzumab/pertuzumab (THP) + neratinib x 4 cycles (up to 8 cycles per physician’s discretion). For C1P2 and C2, we enrolled Stage III – IV primary IBC patients. In C1P2, patients with HER2+ IBC received neratinib (RP2D) combined with THP x 4 cycles followed by doxorubicin/cyclophosphamide (AC) x 4 cycles. Per stage I design, 11 patients were enrolled with plan to enroll 20 more patients in Stage II if at least 6 had a pCR. In C2, patients with HER2-/HR+ IBC received neratinib 200 mg/day combined with paclitaxel x 4 cycles followed by AC x 4 cycles. Stage I design planned for enrollment of 16 patients with enrollment of 15 more patients on stage II, if at least 2 Stage I patients had pCR. In all three cohorts, patients initiated prophylactic anti-diarrheal medication (loperamide & budesonide) with the first dose of neratinib. Results: From 2018 to 2022, thirty-four patients were enrolled and treated (n=4 C1P1B, n=14 C1P2, n=16 C2). In C1P1B, observed DLTs (dose limiting toxicities) were Grade (Gr) 2 Diarrhea, n=2 (50%); Gr3 diarrhea, n=2 (50%); 2 patients had a serious adverse event (SAE); 3 patients (55%) had Gr2 nausea. The RP2D was established at 80 mg/day (dose level 0). For patients in C1P2, the most frequently occurring adverse events (AEs) included Gr2 Alopecia, n=14 (100%); Gr2&3 Diarrhea, n=14 (100%); Gr2/3 Nausea, n=12 (86%); Gr2/3 Anemia, n=7 (50%); Gr2/3 Fatigue, n=8 (57%); Gr2/3 Hypokalemia, n=6 (57%); and Gr2/3 Neutrophil count decreased, n= 7 (50%). 6 patients had an SAE. Of the first 11 patients, 5 (46%) had pCR, 1 (9%) RCB-1, 1 (9%) RCB-II and 1 (9%) RCB-III. Three patients stopped study treatment for toxicity (27%), were non-evaluable and replaced. Of these, one had RCB-III (33.3%), one progression of disease (PD) (33.3%), and one came off study for toxicity (33.3%). Rather than replacing additional non-evaluable patients, the study was closed to new patient accrual. In C2, the most frequently occurring AEs were Gr2 diarrhea, n=7(44%); Gr3 diarrhea, n=8 (50%); Gr2 alopecia, n=14 (88%); Gr2/3 Anemia, n=10 (63%); Gr2/3 Nausea, n=7 (44%); Gr2/3 Neutropenia, n= 7 (44%). 3 patients had an SAE. Of 16 patients in this cohort, 1 had pCR (6%), 5 RCB-II (31%), 4 RCB-III (25%), 3 came off study for toxicity (19%) and 3 had PD (19%). C2 also closed to new patient accrual given the high toxicity profile. Conclusion: The addition of neratinib did not improve the pCR rate in HER2+ or HER2-/HR+ subtypes of IBC, and increased toxicities were observed. The trial closed to new patient entry March 2022. However, some patients achieved significant response. Biomarker analysis is ongoing. Evaluable participants will continue long-term follow-up per protocol. Acknowledgments: This study is supported by PUMA Biotechnology. Citation Format: Angela N. Marx, Megumi Kai, Min Fu, Hope E. Murphy, Jie S. Willey, Huiming Sun, Angela Alexander, Roland L. Bassett, Gary J. Whitman, H. T. Carisa Le-Petross, Miral Patel, Banu K. Arun, Sausan Abouharb, Parijatham S. Thomas, Carlos H. Barcenas, Nuhad K. Ibrahim, Vicente Valero, Naoto T. Ueno, Rachel M. Layman, Bora Lim, Wendy Woodward, Anthony Lucci. A phase 1b study of neratinib with THP in metastatic and locally advanced breast cancer, and phase II study of THP followed by AC in HER2 + primary inflammatory breast cancer (IBC), and neratinib with taxol followed by AC in HR+/HER2- IBC [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-06-09.

Different Prognostic Values of Tumour and Nodal Response to Neoadjuvant Chemotherapy Depending on Subtypes of Inflammatory Breast Cancer, a 317 Patient-Study.

Simple SummaryInflammatory breast cancer is a rare entity associated with a poor prognosis, especially for the triple-negative subtype. This study investigates the independent prognostic value of tumour and nodal responses after neoadjuvant chemotherapy. It shows that tumour and lymph node responses did not have the same prognostic value regarding HR and HER2 statuses. We identified a subgroup of patients with triple-negative inflammatory breast cancer with residual lymph node disease for whom adjuvant treatment intensification may be worth investigating.Inflammatory breast cancer (IBC) is a rare entity with a poor prognosis. We analysed the survival outcomes of patients with nonmetastatic IBC and the prognostic value of tumour or nodal responses to assess their individual prognostic impact across IBC subtypes. This retrospective multicentre study included patients diagnosed with IBC between 2010 and 2017 to account for advances in neoadjuvant systemic therapies and modern radiotherapy at seven oncology centres in France. Three hundred and seventeen patients were included and analysed. After a median follow-up of 52 months, the 5-year DFS was lower for triple-negative (TN) (50.1% vs. 63.6%; p < 0.0001). After multivariate analyses, incomplete nodal response was the only significant prognostic factor in the triple-negative group (HR:6.06). The poor prognosis of TN-IBC was reversed in the case of nodal response after neoadjuvant chemotherapy. Breast response does not appear to be a decisive prognostic factor in patients with TN-IBC compared to lymph node response. Despite improvements in neoadjuvant treatments, IBC remains associated with a poor prognosis. In TN-IBC patients, lack of pathological complete node response was associated with poorer survival than any other group. Treatment intensification strategies are worth investigating.

Characterization of the Immune Microenvironment in Inflammatory Breast Cancer Using Multiplex Immunofluorescence

Introduction: Inflammatory breast cancer (IBC) is an aggressive form of breast cancer with a poorly characterized immune microenvironment. Methods: We used a five-colour multiplex immunofluorescence panel, including CD68, CD4, CD8, CD20, and FOXP3 for immune microenvironment profiling in 93 treatment-naïve IBC samples. Results: Lower grade tumours were characterized by decreased CD4+ cells but increased accumulation of FOXP3+ cells. Increased CD20+ cells correlated with better response to neoadjuvant chemotherapy and increased CD4+ cells infiltration correlated with better overall survival. Pairwise analysis revealed that both ER+ and triple-negative breast cancer were characterized by co-infiltration of CD20 + cells with CD68+ and CD4+ cells, whereas co-infiltration of CD8+ and CD68+ cells was only observed in HER2+ IBC. Co-infiltration of CD20+, CD8+, CD4+, and FOXP3+ cells, and co-existence of CD68+ with FOXP3+ cells correlated with better therapeutic responses, while resistant tumours were characterized by co-accumulation of CD4+, CD8+, FOXP3+, and CD68+ cells and co-expression of CD68+ and CD20+ cells. In a Cox regression model, response to therapy was the most significant factor associated with improved patient survival. Conclusion: Those results reveal a complex unique pattern of distribution of immune cell subtypes in IBC and provide an important basis for detailed characterization of molecular pathways that govern the formation of IBC immune landscape and potential for immunotherapy.

Pattern of distant metastases in inflammatory breast cancer - A large-cohort retrospective study.

Inflammatory breast cancer (IBC) is a fatal form of breast cancer. IBC patients present with unfavorable prognosis mainly attributable to high risk of distant metastasis. Thus, in this cohort study, we aimed to explore metastatic profiles of different molecular subtypes of IBC and elucidate the clinical and prognostic characteristics among different metastatic sites. Patients diagnosed as IBC between 2010 and 2016 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Chi-square tests were performed to compare metastatic distribution among different molecular subtypes. We further used odds ratio calculation to analyze the combined metastatic patterns. Kaplan-Meier methods and multivariate Cox regression models were applied to analyze survival data among different metastatic organs. In total, we enrolled 635 IBC patients between 2010 and 2014 as the training cohort and 242 IBC patients between 2015 and 2016 as the validation cohort, All the included patients were recorded with known metastatic status, follow-up data and molecular subtype. In the present study, we elaborated the following three points: (1) Elucidating the distribution of single-organ metastases in IBC. Bone and brain were the most and least common metastatic lesions for all subtypes of IBC, separately. (2) Clarifying the combined metastatic patterns and tendency of co-metastases. Bi-organ metastasis occurred most frequently among all combined metastases. Several combinations, such as liver and bone, lung and brain, were preferential for bi-organ metastasis. (3) Analyzing prognostic values of single-organ and bi-organ metastases. All single-organ distal metastases were independent risk factors indicating an unfavorable prognosis. In conclusion, our results would provide more information for clinical decision and future studies.

Toward precision medicine in inflammatory breast cancer.

Inflammatory breast cancer (IBC) is an aggressive, although infrequent form of invasive breast cancer. Despite some advances in systemic treatment, even in the early setting, with combined-modality approach being the current recommended standard of care, the prognosis of IBC still remains unfavorable and has not significantly improved over time. Thus, a better understanding of the biology of IBC is eagerly awaited in order to identify possible targets for new drug development. This paper aims to provide an overview on recent data on the molecular and biological features of IBC and on possible targetable pathways. Molecular subtypes of IBC, similarly to other forms of breast cancer, have both therapeutic and prognostic implications. Moreover, few activated pathways have been described in IBC, including angiogenesis, epidermal growth factor receptor (EGFR), Janus kinase/signal transducer of activation (JAK/STAT) signaling and phosphoinositide 3-kinase/Akt/mTOR (PI3K/AKT/mTOR) pathways. However, when tested in clinical trials, agents targeting these pathways have provided only small benefit. Several clinical trials are currently ongoing investigating combination of standard chemotherapeutics, new targeted agents and immunotherapy. Moreover, tumor microenvironment (TME) is likely to play a central role in the disease; targeting the components of the tumor stroma may represent an interesting therapeutic strategy.

Toward precision medicine in inflammatory breast cancer

Inflammatory breast cancer (IBC) is an aggressive, although infrequent form of invasive breast cancer. Despite some advances in systemic treatment, even in the early setting, with combined-modality approach being the current recommended standard of care, the prognosis of IBC still remains unfavorable and has not significantly improved over time. Thus, a better understanding of the biology of IBC is eagerly awaited in order to identify possible targets for new drug development. This paper aims to provide an overview on recent data on the molecular and biological features of IBC and on possible targetable pathways. Molecular subtypes of IBC, similarly to other forms of breast cancer, have both therapeutic and prognostic implications. Moreover, few activated pathways have been described in IBC, including angiogenesis, epidermal growth factor receptor (EGFR), Janus kinase/signal transducer of activation (JAK/STAT) signaling and phosphoinositide 3-kinase/Akt/mTOR (PI3K/AKT/mTOR) pathways. However, when tested in clinical trials, agents targeting these pathways have provided only small benefit. Several clinical trials are currently ongoing investigating combination of standard chemotherapeutics, new targeted agents and immunotherapy. Moreover, tumor microenvironment (TME) is likely to play a central role in the disease; targeting the components of the tumor stroma may represent an interesting therapeutic strategy.

413 (PB-046) - Molecular subtypes in inflammatory breast cancer: A descriptive analysis using the Netherlands cancer registry

413 (PB-046) - Molecular subtypes in inflammatory breast cancer: A descriptive analysis using the Netherlands cancer registry

Interferon-induced transmembrane protein 1 (IFITM1) overexpression enhances the aggressive phenotype of SUM149 inflammatory breast cancer cells in a signal transducer and activator of transcription 2 (STAT2)-dependent manner.

BackgroundInflammatory breast cancer (IBC) is a very aggressive and lethal subtype of breast cancer that accounts for about 4 % of all breast cancers diagnosed in the United States. Despite the efforts of several investigators to identify the molecular factors driving the aggressive phenotype of IBC, a great deal is still unknown about the molecular underpinnings of the disease. In the present study, we investigated the role of interferon-induced transmembrane protein 1 (IFITM1), a well-known interferon-stimulated gene (ISG), in promoting the aggressiveness of SUM149 IBC cells.MethodsWestern blot and real-time polymerase chain reaction analyses were performed to assess the protein and messenger RNA (mRNA) levels of IFITM1 and other ISGs in three IBC cell lines: SUM149, MDA-IBC-3, and SUM190. IFITM1 expression and cellular localization were assessed by using immunofluorescence, while the tumorigenic potential was assessed by performing cell migration, invasion, and colony formation assays. Small interfering RNA and short hairpin RNA knockdowns, enzyme-linked immunosorbent assays, and luciferase assays were performed to determine the functional significance of IFITM1 and signal transducers and activators of transcription 1 and 2 (STAT1/2) in SUM149 cells.ResultsWe found that IFITM1 was constitutively overexpressed at the mRNA and protein levels in triple-negative SUM149 IBC cells, but that it was not expressed in SUM190 and MDA-IBC-3 IBC cells, and that suppression of IFITM1 or blockade of the IFNα signaling pathway significantly reduced the aggressive phenotype of SUM149 cells. Additionally, we found that knockdown of STAT2 abolished IFITM1 expression and IFITM1 promoter activity in SUM149 cells and that loss of STAT2 significantly inhibited the ability of SUM149 cells to proliferate, migrate, invade, and form 2-D colonies. Notably, we found that STAT2-mediated activation of IFITM1 was particularly dependent on the chromatin remodeler brahma-related gene 1 (BRG1), which was significantly elevated in SUM149 cells compared with SUM190 and MDA-IBC-3 cells.ConclusionsThese findings indicate that overexpression of IFITM1 enhances the aggressive phenotype of triple-negative SUM149 IBC cells and that this effect is dependent on STAT2/BRG1 interaction. Further studies are necessary to explore the potential of IFITM1 as a novel therapeutic target and prognostic marker for some subtypes of IBCs.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-016-0683-7) contains supplementary material, which is available to authorized users.

Epidemiological risk factors associated with inflammatory breast cancer subtypes.

In this single-institution case-control study, we identified risk factors associated with inflammatory breast cancer (IBC) subtypes based on staining of estrogen receptor (ER), progesterone receptor (PR) and expression of human epidermal growth factor 2 (HER2neu) to determine distinct etiologic pathways. We identified 224 women with IBC and 396 cancer-free women seen at the MD Anderson Cancer Center. Multinomial logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between breast cancer risk factors and the IBC tumor subtypes: luminal (ER+ and/or PR+/HER2neu-), HER2neu+ (any ER and PR, HER2neu+), and triple-negative (ER-/PR-/HER2neu-). In multivariable analysis, compared with women age ≥26 at first pregnancy, women age <26 had a higher risk of triple-negative IBC (OR 3.32, 95% CI 1.37-8.05). Women with a history of breast-feeding had a lower risk of triple-negative (OR 0.30; 95% CI 0.15-0.62) and luminal IBC (OR 0.35, 95% CI 0.18-0.68). A history of smoking was associated with an increased risk of luminal IBC (OR 2.37; 95% CI 1.24-4.52). Compared with normal-weight women, those who were overweight or obese (body mass index ≥25kg/m(2)) had a higher risk of all three tumor subtypes (p<0.01 for all subtypes). Overweight or obese status is important modifiable risk factor for IBC of any subtype. Modifiable risk factors, age at first pregnancy (≥26), breast-feeding, and smoking may be associated with specific IBC subtypes. These results highlight the importance of evaluating epidemiologic risk factors for IBC for the identification of subtype-specific prevention strategies.

Prognostic impact of hormone receptor- and HER2-defined subtypes in inflammatory breast cancer treated with high-dose chemotherapy: a retrospective study.

Purpose: Studies examining high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDC-AHSCT) strategies in inflammatory breast cancer (IBC), showed encouraging results in terms of disease-free survival (DFS), and overall survival (OS). The lack of data regarding HER2 status in all of these studies prevented any prognostic analysis involving breast cancer subtypes.Methods: All consecutive female patients treated for IBC with HDC and AHSCT at Institut Paoli-Calmettes between 2003 and 2012 were included. Since 2005, trastuzumab was included in initial treatment. Patient, tumor and treatment characteristics were collected. Patients were categorized in three subtypes based on hormonal receptor (HR) and HER2 status of the primary tumor: Luminal, (HR+/HER2-), HER2 (HER2+, any HR), and triple negative (TN) (HER2- and HR-). The main objective was the analysis of OS according to the IHC subtypes.Results: Sixty-seven patients were included. Eleven patients received trastuzumab. Median follow up was 80.04 months (95% CI 73.2-88.08). Five-year OS and DFS for the whole population patients were 74% (95% CI 61-83) and 65 % (95% CI 52-75), respectively. OS differed across subtypes (p=0.057) : HER2 subgroup appeared to have the best prognosis with a 5-year OS of 89% (95% CI 64-97) compared to 57% (95% CI 33-76) for the TN subgroup (HR 5.38, 95% CI 1.14-25.44; p=0.034).Conclusions: In IBC patients receiving HDC-AHSCT, OS favorably compares with data available in the literature on similar groups of patients. TN patients carried the least favourable OS and HER2 patients, half of them also receiving trastuzumab, had the best outcome. These findings provide additional information and options for patients with IBC and who could potentially benefit of HDC-AHSCT.

Abstract P6-14-08: Risk factors for developing inflammatory breast cancer: Unique trends among a single patient population

Abstract Introduction: Inflammatory breast cancer (IBC) is a virulent form of breast cancer, characterized by skin erythema and edema associated with enlargement of the breast rapidly occurring within 3-6 months (mo). Because of its rarity (&amp;lt;5% incidence), there is a paucity of data identifying epidemiologic risk factors, which may shed light on the potential causes of IBC, and guide prevention strategies. Methods: This study utilized retrospective data obtained from an IRB approved database of 275 patients (pts) with IBC evaluated at Dana Farber Cancer Institute (DFCI) from 1997-2012. Pts with confirmed invasive breast cancer had documented clinical characteristics of IBC clinically staged as T4d. The statistical software JMP 10 was used to perform statistical tests. Chi Square Tests, Fisher’s Exact Tests, and descriptive statistics were compiled. Results: The mean age of diagnosis among our study population was 50.2 years (yrs). IBC pts were more frequently diagnosed when premenopausal (55%) versus (v) postmenopausal (45%); 25% of pts had metastases upon presentation. The majority of patients (77%) were overweight (BMI 25-29.9) or obese (BMI≥30). More premenopausal pts (80.3%) had a BMI &amp;gt;25 v postmenopausal pts (73.5%). We observed no association with BRCA status among those undergoing genetic testing (13% BRCA positive (pos); 54 tested); however 52% of pts had a family history of breast cancer (5% BRCA pos). The majority of pts (81%) did not undergo genetic testing. The most common IBC subtype was HER2 pos (40%); 19% were triple negative (neg), and 16% were hormone receptor (HR) pos/HER2 neg. We also observed a trend of a longer duration of symptoms prior to diagnosis among younger pts. The mean age of pts who experienced &amp;gt;6 months (mo) of symptoms prior to diagnosis was 42 yrs v the mean age of 51 yrs among those experiencing &amp;lt; 2 mo of symptoms prior to diagnosis. Pts also displayed a temporal trend in diagnosis dependent upon time of year. 57% of pts were diagnosed with IBC during the warmer temperatures (Mar 21 – Sept 20) compared with 43% diagnosed during the cooler temperatures (Sept 21– Mar 20). Conclusion: This retrospective epidemiologic analysis demonstrated various trends in a single population of IBC pts. The association of high BMI and risk of developing IBC among premenopausal women contrasts with that seen in the non-IBC group, i.e. high BMI is a risk factor for non-IBC only among postmenopausal women. Targeting the obesity crisis may be a means of reducing the risk of developing IBC among younger women. A differentiating feature of IBC is the rapid onset of signs and symptoms of IBC, and yet, younger pts had a significant delay in diagnosis of &amp;gt;6 mo compared with older pts. This emphasizes the urgency to educate both pts and providers about IBC and facilitate rapid diagnostic procedures. The seasonal relationship with diagnosis observed in this cohort of IBC pts is intriguing. Investigators have hypothesized an infectious etiology contributing to the development of IBC, namely infection by viruses or bacterial pathogens may play a role in the pathophysiology of IBC. These unique trends seen in the DFCI IBC population deserve further investigation. Citation Format: Randie E White, Laura E Warren, Jennifer R Bellon, Faina Nakhlis, Heather A Jacene, Eren D Yeh, Judith Hirshfield-Bartek, Beth Overmoyer, Inflammatory Breast Cancer International Consortium. Risk factors for developing inflammatory breast cancer: Unique trends among a single patient population [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-14-08.

O1-11-1 - Prognostic Power of Molecular Subtypes in Inflammatory Breast Cancer: a Multicentric Study

Background: Inflammatory breast cancer (IBC) represents up to 15% of all breast cancer in North Africa. However, this form is poorly characterized and its subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied yet. In this study, we compared pathological complete response (pCR) rates, progression free survival (PFS) and overall survival (OS) by HR/HER2 subtype in IBC North African population.Methods: We retrospectively reviewed data of 65 IBC patients from Morocco, Egypt and Tunisia. All patients had received neoadjuvant sequential chemotherapy. Patients included had available information on estrogen receptor (ER, progesterone receptor (PR, HER2 status and Mib1 score. Kaplan Meier method was used to estimate median PFS and OS durations from the time of first cycle of chemotherapy. The Cox proportional hazards regression model was used to determine the effect of molecular subtypes on PFS and OS.Results: The mean patient age was 46.5 years. The histological grade distributions were 55.9% for grade II tumors, 40.7% for grade III. The immune-histochemical study showed that 1.6% of the tumors were classified as luminal A, 69% as luminal B, 9.5% as Her2 overexpressing and 19% as triple negative. The overall pCR rate was 4.5%, with the HR-positive/HER2-positive subtype showing the highest rate (16.66%). The median PFS was 651 days and median OS was 780 days. In the multivariate analysis, there was no significant statistic difference between all the molecular subtype groups regarding PFS and OS.Conclusions: Molecular subtypes had limited predictive and prognostic power in our IBC population. All molecular subtypes of IBC had a poor prognosis. To improve outcome, further specific therapeutic strategies have to be developed in the neoadjuvant setting.

Prognostic power of molecular subtypes in inflammatory breast cancer: A multicentric study.

e11546 Background: Inflammatory breast cancer (IBC) represents up to 15% of all breast cancer in North Africa. However, this form is poorly characterized and its subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied yet.In this study, we compared pathological complete response (pCR) rates, progression free survival (PFS) and overall survival (OS) by HR/HER2 subtype in IBC North African population. Methods: We retrospectively reviewed data of sixty six non metastatic IBC patients from Morocco, Egypt and Tunisia. All patients had received neoadjuvant sequential chemotherapy: 3 cycles of anthracyclines based regimen then 3 cycles of taxanes based regimen. Trastuzumab was associated to taxanes in erb2 overexpressed cases. Patients included had available information on estrogen receptor, progesterone receptor, HER2 status and Mib1 score. Kaplan-Meier method was used to estimate median PFS and OS durations from the time of first cycle of chemotherapy. The Cox proportional hazards...

A Comparison of Criteria to Identify Inflammatory Breast Cancer Cases from Medical Records and the Surveillance, Epidemiology and End Results Data base, 2007-2009

Inflammatory breast cancer (IBC) is a relatively rare and extremely aggressive form of breast cancer that is diagnosed clinically. Standardization of clinical diagnoses is challenging, both nationally and internationally; moreover, IBC coding definitions used by registries have changed over time. This study aimed to compare diagnostic factors of IBC reported in a U.S. Surveillance, Epidemiology, and End Results (SEER) registry to clinical criteria found in the medical records of all invasive breast cancer cases at a single institution. We conducted a medical record review of all female invasive breast cancers (n = 915) seen at an NCI-designated comprehensive cancer center in Detroit from 2007 to 2009. IBC cases were identified based on the presence of the main clinical characteristics of the disease (erythema, edema, peau d'orange). We compared the proportion of IBC out of all breast cancers, using these clinical criteria and the standard SEER IBC codes. In the reviewed cases, the clinical criteria identified significantly more IBC cases (n = 74, 8.1%) than the standard IBC SEER definition (n = 19, 2.1%; p < 0.0001). No IBC cases were identified in the cancer center records using the SEER pathologic coding, which requires the diagnosis of inflammatory carcinoma on the pathology report, a notation that is rarely made. Emphasis must be placed on the documentation of clinical and pathologic characteristics of IBC in the medical record, so that analysis of putative IBC subtypes will be possible. Our results indicate the need for a consensus on the definition of IBC to be utilized in future research.

Long-term treatment efficacy in primary inflammatory breast cancer by hormonal receptor- and HER2-defined subtypes

Subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied in inflammatory breast cancer (IBC). We characterized clinical parameters and long-term outcomes, and compared pathological complete response (pCR) rates by HR/HER2 subtype in a large IBC patient population. We also compared disease-free survival (DFS) and overall survival (OS) between IBC patients who received targeted therapies (anti-hormonal, anti-HER2) and those who did not. We retrospectively reviewed the records of patients diagnosed with IBC and treated at MD Anderson Cancer Center from January 1989 to January 2011. Of those, 527 patients had received neoadjuvant chemotherapy and had available information on estrogen receptor (ER), progesterone receptor (PR), and HER2 status. HR status was considered positive if either ER or PR status was positive. Using the Kaplan-Meier method, we estimated median DFS and OS durations from the time of definitive surgery. Using the Cox proportional hazards regression model, we determined the effect of prognostic factors on DFS and OS. Results were compared by subtype. The overall pCR rate in stage III IBC was 15.2%, with the HR-positive/HER2-negative subtype showing the lowest rate (7.5%) and the HR-negative/HER2-positive subtype, the highest (30.6%). The HR-negative, HER2-negative subtype (triple-negative breast cancer, TNBC) had the worst survival rate. HR-positive disease, irrespective of HER2 status, had poor prognosis that did not differ from that of the HR-negative/HER2-positive subtype with regard to OS or DFS. Achieving pCR, no evidence of vascular invasion, non-TNBC, adjuvant hormonal therapy, and radiotherapy were associated with longer DFS and OS. Hormone receptor and HER2 molecular subtypes had limited predictive and prognostic power in our IBC population. All molecular subtypes of IBC had a poor prognosis. HR-positive status did not necessarily confer a good prognosis. For all IBC subtypes, novel, specific treatment strategies are needed in the neoadjuvant and adjuvant settings.

Abstract P6-12-04: Risk factors for inflammatory breast cancer

Abstract Background: The 5-year survival rates for inflammatory breast cancer (IBC) are significantly lower than non-IBC, highlighting the importance of cancer prevention in IBC. We investigated the risk factors for IBC subtypes based on estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (HER2neu) status to determine distinct etiological pathways. The Morgan Welch Inflammatory Breast Cancer Research Program and Clinic at University of Texas MD Anderson Cancer Center (UTMDACC) treats the largest number of IBC patients in a single center. The center maintains a prospective, comprehensive epidemiology registry, through which we were able to conduct the largest single center case-control study on IBC. Methods: We identified 246 patients diagnosed with IBC using strict consensus criteria and 397 cancer free patients seen at the UTMDACC Dan L. Duncan Cancer prevention clinic. We used logistic regression to estimate the odds ratios (OR) and 95% confidence intervals (CI) for the associations between breast cancer reproductive and lifestyle risk factors and IBC tumor subtypes. The tumor subtypes of IBC patients were classified as ER-positive (ER+/PR+/Her2neu-), Her2neu-positive (Her2neu+) and triple negative (ER-/PR-/Her2neu-). Results: In age-adjusted univariate analysis, body mass index (BMI), history of smoking, number of children, age at first pregnancy, breastfeeding, menopausal status, and first degree family history of breast cancer were statistically significant associated with risk of IBC (p&amp;lt;0.05). In multivariable analysis of IBC tumor subtypes, compared to cancer free controls, patients with triple negative (OR = 3.73, 95% CI = 1.52 – 9.13) and Her2neu-positive (OR = 19.27, CI = 4.14 – 89.62) tumors were significantly more likely to have ≥ 2 vs 0-1 children. Patients with triple negative (OR = 0.19, 95% CI = 0.09 – 0.45) and ER-positive (OR = 0.42, CI = 0.19 – 0.88) tumors were significantly less likely to have a history of breastfeeding. Patients with ER-positive (OR = 5.02, CI = 2.29 – 10.99) tumors were also significantly more likely to have a history of smoking. Patients with triple negative (OR = 6.07, CI = 2.62 – 17.07), ER-positive (OR = 7.22, CI = 2.94 – 17.78) and Her2neu-positive (OR = 12.81, CI = 4.59 – 35.78) were more likely to be overweight or obese (BMI ≥ 25kg/m2). Conclusion: The associations identified suggest that overweight or obese status is an important modifiable risk factor for all IBC subtypes. Triple negative IBC share similar risk factors as non-IBC triple negative tumors with increasing number of children and lack of breastfeeding associated with increased risk. Interestingly lack of breastfeeding was also associated with ER-positive IBC tumors, and Her2neu-positive IBC tumors were associated with increasing number of children; two associations that have not been previously reported. Impact: These results highlight the importance of evaluating epidemiologic risk factors of IBC, which could lead to the identification of subtype specific prevention strategies. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-12-04.

Inflammatory Breast Cancer

INTRODUCTION: The Inflammatory Breast Cancer (IBC) is a very aggressive subtype of breast cancer. Its diagnosis is Clinical, characterized by edema, skin hyperemia in more than a third of the breast surface and papillary retraction in the majority of the cases. The dermal lymphatic vascular infiltration is sign of worse prognosis when it is present. MATHERIALS: From January/1977 until December / 2010 we attended a total of 3. 815 patients with breast cancer, from whom 246 patients had developed IBC (6. 4%), with mean age of 52.5 years old. RESULTS: Among our breast cancer patients, the IBC subtype was clinically staged: IIIB in 173 patients (70. 3%), IIIC in 41 patients (16. 7%) and IV in 32 patients (13. 0%). The TNM-N classification was as follows: N0 in 0. 4% ; N1a in 4.5%, N1b in 51. 2%, N2 in 20. 7% and N3c in 23. 2% of the patients. The right breast was compromised in 40% of the patients and the left breast in 60% of the patients. The more compromised quadrants were: Central Quadrant: 44% and Superoexternal Quadrant in 32, 5%. The Ductal Carcinoma was detected in 98% of the patients. IBC was Bilateral in 03 patients and was detected concomitant with pregnancy/lactation in 07 patients. 91. 1% of the patients were admitted with palpable breast tumor: 50. 4% of them measured from 5. 0 to 10cm in diameter. In our patients, when radical modified mastectomy was performed, the axillary metastasis was observered in 87. 2% of cases. CONCLUSION: proceedings to try the control of IBC using only loco-regional treatment did not show any survival improvement. The overall mortality of the IBC continue elevated because of the high aggressivity and high metastasis rate. The association of newer chemotherapy drugs (Doxorubicin and Taxanes), Radiotherapy and Hormone Therapy associated or not to Surgery ( the Radical Mastectomy is performed when after Chemo and Radiotherapy a biopsy is histologically positive), makes a better loco-regional and distant control as well as a better prognosis in IBC.

Abstract P3-10-01: Epidemiological risk factors and normal breast tissue markers in inflammatory breast cancer

Abstract Background: Inflammatory breast cancer (IBC) is a rare form of aggressive breast cancer with no existing identifiers for screening or prevention strategies. Women with triple-negative (TNBC, ER–, PR–, Her2–) non-inflammatory breast cancer are less likely to breastfeed, and we have shown in adjacent normal breast tissue that this tissue has more foci of stem cells compared to non-TNBC cancers. A disproportionately higher percentage of women with IBC have TNBC relative to women with non-IBC. We hypothesized that adjacent normal tissue in TNBC IBC vs. TN non-IBC may also display unique biological features based on epidemiologic characteristics. Methods: We examined epidemiologic factors by breast cancer receptor subtype in 144 patients diagnosed with IBC in 1991–2011 at MD Anderson Cancer Center. Breast cancer risk factors including parity and breastfeeding were compared between patients with TN and non-TN IBC with chi-square or Wilcoxon rank sum tests. Normal adjacent tissues were stained for stem cell markers CD44+CD49f+CD133/2+ and macrophage marker CD68. Results: The mean age at diagnosis was 52.3 years (range = 23–80) and 83% of patients were non-Hispanic white, 80% were overweight or obese (BMI &amp;gt;25), and 36% were TN IBC. Patients with TN IBC had significantly lower frequency of breastfeeding compared with non-TN IBC, 28% vs. 55%, (p = 0.01). No differences were found in the frequency of other breast cancer risk factors. All 8 IBC adjacent tissue samples showed a distinct spatial distribution of stem cell staining, not limited to the triple negative patients. Compared with 0/60 non-IBC cases, 0/8 triple negative non-IBC, (p = 0.001 Pearson chi-square). Given the high BMI among IBC patients, we further examined normal tissues for the presence of CD68+ cells distributed individually or as clusters exhibiting a “crown-like” pattern (multiple CD 68+ macrophages found around dead adipocytes), and found that 7 of the 8 IBC adjacent tissues were CD68+. Benign biopsies collected from 2 patients at 10 years before diagnosis displayed similar staining, including both stem cell and CD68 staining. Compared with 12/60 non-IBC adjacent tissues were positive for CD68, with 1/8 TN non-IBC, (p = 0.001 Pearson chi-square). Conclusion: We describe for the first time a stem-cell staining pattern unique to IBC present in all IBC tissues examined, including pre-cancer biopsies. Tissue samples from additional patients will be examined to further explore the relationship between stem cells and CD68 positivity with IBC subtypes. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-10-01.