The gene copy number of c-MET has a significant impact on progression-free survival in Korean patients with ovarian carcinoma

The Expression and Amplification of HER2 Has a Significant Impact on the Prognosis of Endometrial Carcinoma in Korean Patients

Objective: The purpose of this study was to analyze the protein overexpression and gene amplification of HER2 in endometrial carcinoma (EC) and to evaluate its role as a prognostic factor in Korean women. Methods: A tissue microarray (TMA) was constructed from samples from 191 patients with diverse histologic types of EC. HER2 protein expression and gene amplification status were analyzed using immunohistochemistry (IHC) and silver in situ hybridization (SISH), respectively. All patients were treated and followed up at a single tertiary medical center in Seoul, Korea, between July 2009 and October 2020. Results: In terms of histological type, among the 191 EC patients, 157 had endometrioid carcinoma, nine had uterine serous papillary carcinoma (USPC), one had clear cell carcinoma, one had squamous cell carcinoma, eight had mixed carcinoma, and 15 had uterine carcinosarcoma (UC). HER2 protein overexpression was observed in eight of the 191 (4.2%) EC patients; of these patients, five had IHC scores of 2+, and three had IHC scores of 3+. The HER2 overexpression rates of USPC, UC, and endometrioid carcinomas were 33.3%, 26.6%, and 0.6%, respectively. HER2 protein overexpression was significant in USPC and UC tissues (p < 0.000) and was associated with poor overall survival (OS) (p < 0.001). HER2 gene amplification was confirmed in seven of 184 patients (3.8%), including three patients with USPC and four patients with UC. OS was significantly shorter in patients who had HER2 amplification (p < 0.001). On multivariate analysis, HER2 expression and HER2 amplification were statistically significantly associated with worse OS (p = 0.006). However, HER2 expression without amplification was not statistically associated with OS (p = 0.993). Conclusions: HER2 protein overexpression and gene amplification are significantly correlated with shorter OS in Korean women. HER2 can be considered an important predictor of survival outcomes in EC patients.

Intermediate between Idiopathic Hypereosinophilia and Chronic Eosinophilic Leukemia: A Report of Two Hypereosinophilic Cases with Possible Novel Molecular Mutations

To distinguish a reactive eosinophilia from its malignant counterpart is challenging. Establishing clonality of the eosinophils is crucial and considered the determining factor for establishing a diagnosis. Cases of hypereosinophilia without clear reactive etiologies, no evidence of end-organ damage, normal cytogenetics, and no molecular mutations are termed as “Idiopathic Hypereosinophilia (IHE).” For cases which lie between the spectrum of chronic eosinophilic leukemia (CEL) and IHE, identification of underlying molecular abnormalities might be helpful in better understanding the disease process and prognosis. Here, we report two cases of hypereosinophilia in which five possible novel molecular mutations were identified by targeted next-generation sequencing (NGS) analysis. They were FBXW7, KM2A, TCF3, ERBB4, and MET. With multiple genetic mutations, these cases could be classified as chronic eosinophilic leukemia. Both these young patients responded well to steroid therapy. While targeted NGS is a useful tool in identifying new molecular mutation associated with hypereosinophilia, our cases raise the question of further investigating this entity and if there is a possibility of an intermediate category lying between the spectrum of CEL and IHE. Defining hypereosinophilia with clonal molecular abnormality as a malignant process may need to be revisited. Even though attempts are being made to identify mutations in IHE, it might be more significant clinically to differentiate them based on response to steroid therapy and prognosis.

The FAM3C locus that encodes interleukin-like EMT inducer (ILEI) is frequently co-amplified in MET-amplified cancers and contributes to invasiveness

BACKGROUND

Gene amplification of MET, which encodes for the receptor tyrosine kinase c-MET, occurs in a variety of human cancers. High c-MET levels often correlate with poor cancer prognosis. Interleukin-like EMT inducer (ILEI) is also overexpressed in many cancers and is associated with metastasis and poor survival. The gene for ILEI, FAM3C, is located close to MET on chromosome 7q31 in an amplification "hotspot", but it is unclear whether FAMC3 amplification contributes to elevated ILEI expression in cancer. In this study we have investigated FAMC3 copy number gain in different cancers and its potential connection to MET amplifications.

METHODS

FAMC3 and MET copy numbers were investigated in various cancer samples and 200 cancer cell lines. Copy numbers of the two genes were correlated with mRNA levels, with relapse-free survival in lung cancer patient samples as well as with clinicopathological parameters in primary samples from 49 advanced stage colorectal cancer patients. ILEI knock-down and c-MET inhibition effects on proliferation and invasiveness of five cancer cell lines and growth of xenograft tumors in mice were then investigated.

RESULTS

FAMC3 was amplified in strict association with MET amplification in several human cancers and cancer cell lines. Increased FAM3C and MET copy numbers were tightly linked and correlated with increased gene expression and poor survival in human lung cancer and with extramural invasion in colorectal carcinoma. Stable ILEI shRNA knock-down did not influence proliferation or sensitivity towards c-MET-inhibitor induced proliferation arrest in cancer cells, but impaired both c-MET-independent and -dependent cancer cell invasion. c-MET inhibition reduced ILEI secretion, and shRNA mediated ILEI knock-down prevented c-MET-signaling induced elevated expression and secretion of matrix metalloproteinase (MMP)-2 and MMP-9. Combination of ILEI knock-down and c-MET-inhibition significantly reduced the invasive outgrowth of NCI-H441 and NCI-H1993 lung tumor xenografts by inhibiting proliferation, MMP expression and E-cadherin membrane localization.

CONCLUSIONS

These novel findings suggest MET amplifications are often in reality MET-FAM3C co-amplifications with tight functional cooperation. Therefore, the clinical relevance of this frequent cancer amplification hotspot, so far dedicated purely to c-MET function, should be re-evaluated to include ILEI as a target in the therapy of c-MET-amplified human carcinomas.

Recurrence of ovarian squamous cell carcinoma with MET gene copy number variation: a case report and review of literature

Background

Malignant transformation such as ovarian squamous cell carcinoma (SCC) in ovarian mature cystic teratoma (OMCT) is a rare tumor. The gene mutation of ovarian SCC remains unclear. We herein report a recurrent case of ovarian squamous cell carcinoma with MET gene copy number variation.

Case presentation

A 60-year-old woman presented with recurrence of ovarian SCC 8 months after primary surgery. Adhesiolysis, right abdominal wall mass excision, prosthetics, enterectomy, enterostomy and partial cystectomy were performed by laparoscope. Pathologic examination demonstrated metastatic squamous cell carcinoma in ileocecus, rectum and abdominal wall muscle. MET gene copy number was elevated with copy number of six in this case. Postoperatively, the patient was treated with four cycles of combination chemotherapy with docetaxel and carboplatin. The patient was free of disease at 20 months’ follow-up.

Conclusions

Optimal cytoreductive surgery combined with platinum-based chemotherapy is recommended currently for not only primary tumor but also recurrence. For patients with malignant transformation in OMCT, prompt diagnosis and individualized treatment are crucial for better prognosis. Increased copy number of MET may be correlated with her poor PFS and can be a potential therapeutic target for this case.

A model for the impact of FFPE section thickness on gene copy number measurement by FISH

Fluorescent in situ hybridization (FISH) assays to detect gene amplification such as HER2 or MET in tumors are used for prognosis evaluation and selection of targeted therapies. Although FISH guidelines recommended 4~6 μm FFPE sections, many laboratories use 2~3 μm sections, which is a common practice for H&E staining and immunohistochemistry. A former study concluded that section thickness did not affect FISH results. We found, however, that thinner FFPE sections may lead to false negative results for gene amplification. A mathematic model was constructed and cell-line based controls with known gene copy number were prepared, and the model had a reasonable fit with the experimental data. The model revealed that even when counting the apparently full-sized nuclear images, many of them have partial volumes, which leads to under-estimation of gene copy number. Therefore, improperly thinner sections are prone to give false negative results, and thicker sections give a better approximation to the true value. The discrepancy between this and the former study was discussed. In summary, the model applies generally to FISH/ISH detection of gene copy number, and section thickness is an important parameter to control for precision medicine research, assay development, clinical trials and daily practice in pathology laboratory.

Increased MET gene copy number negatively affects the survival of esophageal squamous cell carcinoma patients

BACKGROUNDS

Since Mesenchymal epithelial transition (MET) amplification has been regarded as a potential treatment target, the knowledge of its prevalence and prognostic importance is crucial. However, its clinical pathologic characteristics are not well known in esophageal squamous cell carcinoma (ESCC).

METHODS

We investigated MET gene status with fluorescence in situ hybridization (FISH) assay in 495 ESCC cases using tissue microarrays. Prognostic significance as well as correlations with various clinicopathological parameters was evaluated.

RESULTS

Among 495 patients, 28 (5.7%) cases were MET FISH positive, including 5 cases (1%) with true gene amplification. There were no statistically significant associations between MET FISH-positivity and clinicopathologic characteristics. A significantly poorer prognosis was observed in 28 patients with MET FISH-positivity (disease free survival/DFS, P < 0.001 and overall survival/OS, P = 0.001). Multivariate analysis revealed MET FISH-positivity was an independent prognostic factor for DFS (hazard ratio/HR, 1.953; 95% confidence interval/CI, 1.271-2.999; P = 0.002) and OS (HR, 1.926; 95% CI, 1.243-2.983; P = 0.003). MET FISH-positivity was associated with DFS (P = 0.022 and 0.020) and OS (P = 0.046 and 0.024) both in stage I-II ESCC and in stage III-IVa ESCC. No statistical significance (DFS, P = 0.492 and OS, P = 0.344) was detected between stage I-II ESCC with MET FISH-positivity and stage III-IVa ESCC with FISH-negativity.

CONCLUSIONS

Increased MET gene copy number is an independent prognostic factor in ESCC, and ESCC might have potentially been up-staged by increased MET gene copy number. The results indicate that increased MET gene copy number is a very promising parameter, in clinical therapy and follow-up plans.