Genomic alterations and evolution of cell clusters in metastatic invasive micropapillary carcinoma of the breast

Invasive micropapillary carcinoma (IMPC) has very high rates of lymphovascular invasion and lymph node metastasis and has been reported in several organs. However, the genomic mechanisms underlying its metastasis are unclear. Here, we perform whole-genome sequencing of tumor cell clusters from primary IMPC and paired axillary lymph node metastases. Cell clusters in multiple lymph node foci arise from a single subclone of the primary tumor. We find evidence that the monoclonal metastatic ancestor in primary IMPC shares high frequency copy-number loss of PRDM16 and IGSF9 and the copy number gain of ALDH2. Immunohistochemistry analysis further shows that low expression of IGSF9 and PRDM16 and high expression of ALDH2 are associated with lymph node metastasis and poor survival of patients with IMPC. We expect these genomic and evolutionary profiles to contribute to the accurate diagnosis of IMPC.

Intertumoral Heterogeneity of Primary Breast Tumors and Synchronous Axillary Lymph Node Metastases Reflected in IHC-Assessed Expression of Routine and Nonstandard Biomarkers

Breast cancer (BC) remains a significant healthcare challenge. Routinely, the treatment strategy is determined by immunohistochemistry (IHC)-based assessment of the key proteins such as estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67. However, it is estimated that over 75% of deaths result from metastatic tumors, indicating a need to develop more accurate protocols for intertumoral heterogeneity assessment and their consequences on prognosis. Therefore, the aim of this preliminary study was the identification of the expression profiles of routinely used biomarkers (ER, PR, HER2, Ki-67) and additional relevant proteins [Bcl-2, cyclin D1, E-cadherin, Snail+Slug, gross cystic disease fluid protein 15 (GCDFP-15), programmed death receptor 1 (PD-L1), and phosphatase of regenerating liver 3 (PRL-3)] in breast primary tumors (PTs) and paired synchronous axillary lymph node (ALN) metastases. A total of 67 tissue samples met the inclusion criteria for the study. The expression status of biomarkers was assessed in PTs and ALN metastases using tissue microarrays followed by IHC. In 11 cases, the shift of intrinsic molecular BC subtype was noticed between PTs and paired ALN metastases. Moreover, a significant disproportion in E-cadherin presence (p = 0.0002) was noted in both foci, and the expression status of all proteins except for HER2 demonstrated considerable variance (k = 1, p < 0.0001). Importantly, in around 30% of cases, the ALN metastases demonstrated discordance, i.e., loss/gain of expression, compared to the PTs. Intertumoral synchronous heterogeneity in both foci (primary tumor and node metastasis) is an essential phenomenon affecting the clinical subtype and characteristics of BC. Furthermore, a greater understanding of this event could potentially improve therapeutic efficacy.

Aldehyde dehydrogenase 1 (ALDH1) immunostaining in axillary lymph node metastases is an independent prognostic factor in ALDH1-positive breast cancer

Objective To determine whether aldehyde dehydrogenase 1 (ALDH1) immunostaining in axillary lymph node metastases in patients with breast cancer is associated with poor clinical prognosis. Methods This retrospective study reviewed data from the medical records of patients with immunohistochemistry-confirmed invasive ductal carcinoma (IDC) and 1–3 metastatic lymph nodes in the ipsilateral axilla between December 2012 and July 2015. The association between ALDH1 immunostaining in axillary lymph node metastases and clinical parameters and prognosis was analysed using χ2-test, Kaplan–Meier survival analysis, univariate and multivariate Cox regression analyses. Results A total of 229 patients with IDC were enrolled in the study. The median follow-up was 61 months (range, 20–89 months). Patients with ALDH1-positive axillary lymph node metastases had significantly shorter relapse-free survival and overall survival compared with those with ALDH1-negative axillary lymph node metastases. ALDH1 immunostaining in axillary lymph node metastases was a significant predictor of poor prognosis in univariate and multivariate analyses. Conclusion This large study with long-term follow-up suggests that ALDH1 immunostaining in axillary lymph node metastases is an independent predictor of poor prognosis in patients with breast cancer. The clinical relevance of this finding should be confirmed in further well-designed prospective studies.

Axillary Nodal Metastases from Carcinoma of Unknown Primary (CUPAx): Role of Contrast-Enhanced Spectral Mammography (CESM) in Detecting Occult Breast Cancer

Axillary lymph node metastases of occult breast cancer (CUPAx) is an unusual condition that represents both a diagnostic and therapeutic challenge. The first steps in the diagnostic work-up of patients with CUPAx are the histological analysis of the lymph node metastasis and the execution of basic breast diagnostic imaging (mammography and ultrasound). In the case of occult breast cancer, breast Magnetic Resonance (MR) must be performed. Breast MR identifies a suspicious lesion in many patients and second-look ultrasound detects a corresponding ultrasound alteration in about half of cases, allowing the performance of a US-guided biopsy. In the case of an MR-only lesion, MR-guided biopsy is mandatory. We present a case of CUPAx in which contrast-enhanced spectral mammography (CESM) is used to help the detection of occult breast cancer and to guide stereotactic vacuum breast biopsy (VABB). CESM is a new breast imaging technique that is proving to have good performance in breast cancer detection and that is showing potential in the identification of occult breast cancer in a CUPAx setting. The use of an innovative and personalized breast imaging approach in breast cancer patients improves diagnostic possibilities and promises to become the focus in decision strategies.

Heterogeneity between core needle biopsy and synchronous axillary lymph node metastases in early breast cancer patients: Comparison of HER2, estrogen and progesterone receptor expression profiles during primary treatment regime.

e12565 Background: Therapeutic decisions for the primary treatment of breast cancer is commonly based on the expression profiles of estrogen (ER), progesterone (PR) and the human epidermal growth factor 2 (HER2) receptors. However, breast cancer is a very heterogeneous disease, and receptor changes were manifold reported during progression. Little is known about receptor discordance in the primary setting. Here, we compared receptor expression profiles between core needle biopsy (CNB) of the breast tumor tissue and synchronous axillary lymph node metastases (LNM) not at recurrence, but at the primary treatment. Methods: In a German single center study, we retrospectively analyzed 175 breast cancer patients with axillary synchronous LNM. 69,7% of our patients were without any upfront therapy. Profiles of ER, PR and HER2 were immunohistochemically analyzed using the common cut-off at 10% positive tumor cells vs. the controversially discussed low-positive cut-off at 1%. Receptor status was compared between CNB specimens of the primary tumor tissue and axillary LNM. Further, clinicopathological characteristics were correlated to receptor changes. Results: The discordance rates between CNB and axillary LNM were 12.7% for HER2, 6.9% for ER and 22.6% for PR using the ≥1% cut-off, respective 7.5% for ER and 25.6% for PR when using the ≥10% cut-off-level. The most frequently occurring change was a PR loss. Analysis of clinical parameters revealed a significant association of ER change between CNB and LNM in younger patients (p < 0.01) with increased proliferation marker Ki-67 (p = 0.04). Conclusions: Receptor discordance between CNB and synchronous axillary LNM appears to exist at the primary setting already. Hence, receptor profiles of the tumor tissue and the synchronous axillary LNM should be considered for treatment decision.

FGFR1 copy number in breast cancer: associations with proliferation, histopathological grade and molecular subtypes

AimsFGFR1 is located on 8p11.23 and regulates cell proliferation and survival. Increased copy number of FGFR1 is found in several cancers including cancer of the breast. ZNF703 is located close to FGFR1 at 8p11-12 and is frequently expressed in the luminal B subtype of breast cancer. Using tissue samples from a well-described cohort of patients with breast cancer with long-term follow-up, we studied associations between FGFR1 copy number in primary breast cancer tumours and axillary lymph node metastases, and proliferation status, molecular subtype and prognosis. Furthermore, we studied associations between copy number increase of FGFR1 and copy number of ZNF703.MethodsWe used fluorescence in situ hybridisation for FGFR1 and the chromosome 8 centromere applied to tissue microarray sections from a series of 534 breast cancer cases.ResultsWe found increased copy number (≥4) of FGFR1 in 74 (13.9%) of tumours. Only 6 of the 74 cases with increased copy number were non-luminal. Increased FGFR1 copy number was significantly associated with high Ki-67 status, high mitotic count and high histopathological grade, but not with prognosis. Forty-two (7.9%) cases had mean copy number ≥6. Thirty of these showed ZNF708 copy number ≥6.ConclusionsOur results show that FGFR1 copy number increase is largely found among luminal subtypes of breast cancer, particularly luminal B (HER2−). It is frequently accompanied by increased copy number of ZNF703. FGFR1 copy number increase is associated with high histopathological grade and high proliferation. However, we did not discover an association with prognosis.

Are Breast Cancer Nomograms Still Valid to Predict the Need for Axillary Dissection?

Background: Nomograms can help in estimating the nodal status among clinically node-negative patients. Yet their validity in external cohorts over time is unknown. If the nodal stage can be estimated preoperatively, the need for axillary dissection can be decided. Objectives: The aim of this study was to validate three existing nomograms predicting 4 or more axillary lymph node metastases. Method: The risk for ≥4 lymph node metastases was calculated for n = 529 eligible breast cancer patients using the nomograms of Chagpar et al. [Ann Surg Oncol. 2007;14:670–7], Katz et al. [J Clin Oncol. 2008;26(13):2093–8], and Meretoja et al. [Breast Cancer Res Treat. 2013;138(3):817–27]. Discrimination and calibration were calculated for each nomogram to determine their validity. Results: In this cohort, the AUC values for the Chagpar, Katz, and Meretoja models were 0.79 (95% CI 0.74–0.83), 0.87 (95% CI 0.83–0.91), and 0.82 (95% CI 0.76–0.86), respectively, showing good discrimination between patients with and without high nodal burdens. Conclusion: This study presents support for the use of older breast cancer nomograms and confirms their current validity in an external population.