Aeri Kim

Fibronectin expression in carcinoma cells correlates with tumor aggressiveness and poor clinical outcome in patients with invasive breast cancer

Fibronectin (FN), a large heterodimeric glycoprotein, can be found in soluble form in plasma or in insoluble form as an extracellular matrix protein. Cellular FN is produced by various types of benign and malignant epithelial and mesenchymal cells and is widely distributed in malignant tumors. We evaluated FN expression in cancer cells (epithelial FN; E-FN) and intratumor stroma (stromal FN, S-FN) of 1596 invasive breast cancer samples using immunohistochemistry on tissue microarrays. Correlations of FN expression with clinicopathologic factors and patient survival were investigated. Among 1512 informative cases, E-FN expression was observed in 355 (23.5%) cases, and S-FN expression showed no/weak staining in 362 (23.9%), moderate staining in 744 (49.2%), and strong staining in 406 (26.9%) cases. E-FN expression was correlated with advanced pT (P < .001) and pN (P < .001), histologic type (P = .006), high histologic grade (P < .001), lymphovascular invasion (P < .001), hormone receptor negativity (P < .001), and human epidermal growth factor receptor-2 (HER2) positivity (P < .001). Strong S-FN expression showed an association with advanced pN (P = .002), histologic type (P < .001), high histologic grade (P < .001), lymphovascular invasion (P < .001), and HER2 positivity (P < .001). Patients with E-FN expression showed worse overall survival (P < .001) and disease-free survival (P < .001) than did those with negative expression of FN. E-FN expression was an independent prognostic factor, especially in the hormone receptor-positive group. Expression of S-FN did not have a significant effect on patient survival. In conclusion, E-FN expression could be a promising prognostic marker in patients with invasive breast cancer.

Neuroendocrine differentiation correlates with hormone receptor expression and decreased survival in patients with invasive breast carcinoma.

Invasive breast carcinoma (IBC) with neuroendocrine (NE) differentiation has been controversial in terms of its definition and clinical outcome. We investigated the incidence and clinical significance of NE differentiation in patients with IBC.

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: A Case Report

Plexiform angiomyxoid myofibroblastic tumor (PAMT) is a recently described mesenchymal tumor of the stomach. We report the first case of PAMT in Korea. A 52-yr-old man underwent esophagogastroduodenoscopy due to dyspepsia for 2 yr. There was a submucosal mass with small mucosal ulceration in the gastric antrum. The tumor measured 3.5 × 2.3 cm in size and showed multinodular plexiform growth pattern of bland-looking spindle cells separated by an abundant myxoid or fibromyxoid matrix rich in small thin-walled blood vessels. The tumor cells were negative for CD117 (c-KIT), CD34 and S-100 protein, but diffusely positive for smooth muscle actin consistent with predominant myofibroblastic differentiation. The patient is doing well without recurrence or metastasis for 5 months after surgery. Although there have been limited follow-up data, PAMT is regarded as a benign gastric neoplasm with histological and immunohistochemical charateristics distinguished from gastrointestinal stromal tumor and other mesenchymal tumors of the stomach.

Multiplication of Chromosome 17 Centromere Is Associated with Prognosis in Patients with Invasive Breast Cancers Exhibiting Normal HER2 and TOP2A Status

Purpose This study aimed to investigate the clinical significance of chromosome 17 centromere (CEP17) multiplication (increased copy number of CEP17) related to human epidermal growth factor receptor 2 (HER2) and topoisomerase II alpha (TOP2A) status in patients with invasive breast cancer. Methods We constructed tissue microarrays using 594 invasive breast cancer samples and performed single-color silver-enhanced in situ hybridization (SISH) assay for HER2, TOP2A, and CEP17 to assess for copy number aberrations. The association of CEP17 multiplication with patient survival was analyzed according to HER2 and TOP2A status. Results Among 567 informative cases, HER2 amplification was noted in 22.8%, TOP2A amplification in 8.3% and TOP2A deletion in 11.1%. CEP17 multiplication was identified in 33.2% and was significantly associated with worse overall survival (OS) (p=0.02) and disease-free survival (DFS) (p=0.02). CEP17 multiplication correlated with patient survival in patients with normal TOP2A or non-amplified HER2 status, but the prognostic significance was lost in those with altered TOP2A or amplified HER2. On multivariate analyses, CEP17 multiplication was an independent prognostic factor for poorer OS (p=0.02) and DFS (p=0.01) in patients with normal TOP2A and non-amplified HER2. Conclusion CEP17 multiplication was identified as a promising prognostic marker in patients with invasive breast cancer exhibiting either non-amplified HER2 or normal TOP2A status.

Epithelial-mesenchymal transition phenotype is associated with patient survival in small intestinal adenocarcinoma

Aims: We investigated the clinical significance of epithelial-mesenchymal transition (EMT) phenotype in 184 small intestinal adenocarcinomas (SIACs) based on the expression pattern of EMT-related proteins in cancer cells. Methods: Immunohistochemistry for epithelial (E-cadherin) and mesenchymal (vimentin and fibronectin) markers were performed and cases of SIAC were classified into four subtypes of EMT: complete type (E-cadherin–, vimentin+ and/or fibronectin+), wild type (E-cadherin+, vimentin–, fibronectin–), incomplete 1 type (hybrid type; E-cadherin+, vimentin+ and/or fibronectin+), and incomplete 2 type (null type; E-cadherin–, vimentin–, fibronectin–). Results: We identified 19 (10.3%) cases of complete EMT type, 86 (46.7%) cases of wild type and 79 (43%) cases of incomplete EMT type [hybrid type, 22 (12%) cases; null type, 57 (31%) cases]. Complete EMT phenotype showed a significant association with undifferentiated histology (p < 0.001). Overall survival of SIAC patients with complete EMT phenotype was significantly shorter than those of patients with incomplete (p = 0.001) and wild (p < 0.001) types. In multivariate analysis, complete EMT phenotype was an independent prognostic factor in SIAC patients (hazard ratio 2.3; 95% confidence interval 1.15–4.6; p = 0.019). Conclusion: Complete EMT phenotype stratifies a specific group representing a poor clinical outcome in patients with SIAC.

Mutations of the Epidermal Growth Factor Receptor Gene in Triple-Negative Breast Cancer

Purpose Epidermal growth factor receptor (EGFR) is considered a potential therapeutic target for anti-EGFR therapy in triple-negative breast cancer (TNBC). However, the frequency of EGFR gene mutation in TNBC is low and varies with ethnicity. This study aimed to investigate the incidence of EGFR gene mutation in TNBC. Methods EGFR protein expression was evaluated by immunohistochemistry in tissue microarrays of 493 TNBC cases using four different primary antibodies, which included mutation-specific antibodies. For cases with an immunoreactivity level ≥1+, we performed pyrosequencing analysis for EGFR gene mutation. A case was considered mutation-positive when its mutation frequency minus its limit of detection (LOD) was >10%. Cases with mutation frequency higher than LOD were assessed for EGFR gene mutation status using the Cobas assay and by peptide nucleic acid-mediated polymerase chain reaction (PNA-clamping). Results Among 493 TNBCs, 148 (30.0%) exhibited staining ≥1+ for EGFR, including 78 with 1+, 49 with 2+, and 21 with 3+. Positive EGFR expression (≥2+) was significantly associated with lymphovascular invasion (p=0.010), but not with overall survival (p=0.444) or disease-free survival (p=0.388). None of the 493 TNBCs harbored an EGFR gene mutation. Among 148 cases with an EGFR staining result ≥1+, five (3.4%) showed mutation frequencies (4.4%–10.9%) higher than LOD (2.6%–4.3%) in exons 19 (L747_P753>Q) or 21 (L858R and L861Q) as determined by pyrosequencing. However, Cobas and PNA-clamping failed to detect the presence of EGFR gene mutation in these five cases. Conclusion No activating mutation of EGFR gene of clinical significance was observed in 148 TNBC cases using three commercially available methods. Thus, EGFR gene mutation appears to be an extremely rare event in patients with TNBC.