In stage II/III lymph node-positive breast cancer patients less than 55 years of age, keratin 8 expression in lymph node metastases but not in the primary tumour is an indicator of better survival

Clinical relevance of biomarker discordance between primary breast cancers and synchronous axillary lymph node metastases

Clinical decision-making for patients with breast cancer (BC) is still primarily based on biomarker characteristics of the primary tumor, together with the evaluation of synchronous axillary lymph node metastasis (LNM). In this study, we investigated the prevalence of discordance in the biomarkers and surrogate subtyping between the primary BC and the LNM, and whether subsequent changes would have altered clinical treatment recommendations. In this retrospective study, 94 patients treated for unifocal primary BC and synchronous LNM at Sahlgrenska UniversityHospital during 2018 were included. Estrogen (ER) and progesterone (PR) receptor, Ki67, and HER2 status were assessed in the primary tumor and LNM using immunohistochemistry. Discordances between the primary tumor and the LNM were analyzed for each individual biomarker and surrogate subtyping. The concordance between the primary tumor and the LNM for ER, PR, Ki67, and HER2 status was 98.9%, 89.4%, 72.3%, and 95.8%, respectively. Discordance in surrogate subtyping was found in 28.7% of the tumors and matched LNMs, the majority (81.5%) of which changed to a more favorable subtype in the LNM; most commonly from Luminal B to Luminal A (48.6%). No changes in surrogate subtyping were detected where ER or HER2 status changed from negativity in the BC to positivity in the LNM, thereby showing no additional value in performing immunohistochemistry on the LNM from a treatment decision-making perspective. However, large studies need to be performed that test both the primary BCs and synchronous LNMs for more accurate diagnostics.

Advances in understanding the molecular pathology of gynecological malignancies: the role and potential of RNA sequencing

For many years technological limitations restricted the progress of identifying the underlying genetic causes of gynecologicalcancers. However, during the past decade, high-throughput next-generation sequencing technologies have revolutionized cancer research. RNA sequencing has arisen as a very useful technique in expanding our understanding of genome changes in cancer. Cancer is characterized by the accumulation of genetic alterations affecting genes, including substitutions, insertions, deletions, translocations, gene fusions, and alternative splicing. If these aberrant genes become transcribed, aberrations can be detected by RNA sequencing, which will also provide information on the transcript abundance revealing the expression levels of the aberrant genes. RNA sequencing is considered the technique of choice when studying gene expression and identifying new RNA species. This is due to the quantitative and qualitative improvement that it has brought to transcriptome analysis, offering a resolution that allows research into different layers of transcriptome complexity. It has also been successful in identifying biomarkers, fusion genes, tumor suppressors, and uncovering new targets responsible for drug resistance in gynecological cancers. To illustrate that we here review the role of RNA sequencing in studies that enhanced our understanding of the molecular pathology of gynecological cancers.

Validity of whole genomes sequencing results in neoplasms in precision medicine

OBJECTIVE

To compare the whole genomes sequencing (WGS) results in the 100K Genomes project with the results of routine molecular diagnostics in precision medicine.

MATERIALS AND METHODS

We analysed 374 cancers including a high tumour mutational burden (TMB-high) subgroup, defined as >10 non-synonymous single nucleotide variations per megabase. Colon cancers were evaluated for microsatellite instability (MSI), mismatch repair (MMR) genes and NRAS, KRAS and BRAF mutations using routine molecular diagnostics. Fluorescence in-situ hybridisation/immunohistochemistry was used to evaluate the Her2Neu status in breast cancers.

RESULTS

There was high correlation between WGS and routine diagnostic testing results irrespective of TMB status in colon cancers. Her2Neu status was discordant in 3 out of the 5 TMB-high breast cancers (p=0.049). The presence of ductal carcinoma in-situ correlated significantly with discordance (p=0.04). There were 3 (5%) discordant colorectal cases, all in the KRAS gene, 2 of which were from the non-invasive adenomatous component (p=0.0058). Of the 374 cases we identified 24 tumours with a TMB >10; comprising (colorectal carcinomas (CRCs) n=16, breast carcinomas n=5, bladder urothelial cell cancers n=3). Of the 16 TMB-high colorectal adenocarcinomas, 13 had MSI-high status. The same 13 had defective MMR protein expression. TMB-high colorectal cancers had 100% concordant results between WGS and NGS testing for KRAS, BRAF and NRAS (16/16).

CONCLUSION

The microsatellite and mutational status of colorectal cancers evaluated by WGS seem to correlate well with the routine diagnostic testing if it is ensured that the invasive component is sequenced. Evaluation of WGS results need to be carefully correlated with histomorphology, as tumour heterogeneity/contamination with pre-malignant components needs to be taken into account.

Resistin Activates p65 Pathway and Reduces Glycogen Content through Keratin 8

Resistin is associated with metabolic syndrome and inflammatory conditions. Many studies have suggested that resistin inhibits the accumulation of glycogen; however, the exact mechanisms of resistin-induced decrease in glycogen content remain unclear. Keratin 8 is a typical epithelial intermediate filament protein, but numerous studies suggest a vital role of K8 in glucose metabolism. However, it is still not known whether K8 participates in the mediation of resistin-induced reduction of cellular glycogen accumulation. In this study, we found that resistin upregulated expression of the p65 subunit of NF-κB, which led to the promotion of K8 transcriptional expression; in turn, the expression of K8 inhibited glycogen accumulation in HepG2 cells.

Genistein and Selected Phytoestrogen-Containing Extracts Differently Modulate Antioxidant Properties and Cell Differentiation: an in Vitro Study in NIH-3T3, HaCaT and MCF-7 Cells

During the last decades, plant extracts containing phytoestrogens have increasingly been used as an alternative to oestradiol hormone replacement therapy. The aim of the present study was to compare the effects of genistein with those of different phytoestrogen-containing plant extracts (from red clover flowers and soybeans) on the proliferation and differentiation of NIH-3T3, HaCaT and MCF-7 cells. Our results showed poor correlations between direct anti/pro-oxidant effects and cytotoxicity of the tested samples. In contrast, genistein showed a direct correlation between significant pro-oxidative effects at cytotoxic concentrations and almost no pro-oxidative effects at non-cytotoxic concentrations. Moreover, the tested red clover extract and genistein induced keratin-8 (luminal and prognostic marker in breast cancer) expression only in MCF-7 cells, but this effect was not seen following treatment with the soybean extract. From this point of view, the effect of consumption of phytoestrogens in oestrogen-positive breast cancer remains to be elucidated. In conclusion, our study demonstrates that various phytoestrogen- containing plant extracts and genistein are able to specifically modulate antioxidant properties and differentiation of studied cells.

Histone deacetylase 6 expression in metastatic lymph nodes is a valuable prognostic marker for resected node-positive esophageal squamous cell cancer

Background

Histone deacetylase 6 (HDAC6) exerts enzymatic deacetylation activity on histones and on non-histone substrates and plays a key role in microtubule dynamics and chaperone activities. In addition, previous studies have demonstrated its role in cancer progression. However, its clinical significance in esophageal squamous cell cancer (ESCC) has not been elucidated. We investigated the correlation of HDAC6 expression and clinical outcome in a group of T3N1–3M0 surgically resected ESCCs.

Methods

Tissue microarrays were conducted on 209 surgically resected T3N1–3M0 ESCC tumors, including 163 pairs of primary tumors (PTs) and their corresponding metastatic lymph nodes (MLNs). Immunohistochemistry was utilized to evaluate HDAC6 protein levels. The relationship between patient outcomes and HDAC6 expression was analyzed statistically.

Results

The level of HDAC6 expression in ESCC MLNs was found to be significantly lower than that in PTs (P<0.001). Patients with lower MLN HDAC6 expression demonstrated improved overall survival (P=0.011) and disease-free survival (P=0.012) than those with higher HDAC6 expression. HDAC6 expression levels in PTs revealed no prognostic significance. Multivariate analysis showed that the MLN HDAC6 expression level was an independent prognostic factor for both overall survival (HR 1.456, P=0.029) and disease-free survival (HR 1.432, P=0.033).

Conclusion

High expression of HDAC6 in MLNs but not in PTs suggests a poor prognosis for patients with resected T3N1–3M0 ESCC. We should take into account the protein expression of MLNs when assessing prognosis in patients with lymph-node involvement.

Overview on Clinical Relevance of Intra-Tumor Heterogeneity

Today, clinical evaluation of tumor heterogeneity is an emergent issue to improve clinical oncology. In particular, intra-tumor heterogeneity (ITH) is closely related to cancer progression, resistance to therapy, and recurrences. It is interconnected with complex molecular mechanisms including spatial and temporal phenomena, which are often peculiar for every single patient. This review tries to describe all the types of ITH including morphohistological ITH, and at the molecular level clonal ITH derived from genomic instability and nonclonal ITH derived from microenvironment interaction. It is important to consider the different types of ITH as a whole for any patient to investigate on cancer progression, prognosis, and treatment opportunities. From a practical point of view, analytical methods that are widely accessible today, or will be in the near future, are evaluated to investigate the complex pattern of ITH in a reproducible way for a clinical application.

Tumour heterogeneity: principles and practical consequences

Two major reasons compel us to study tumour heterogeneity: firstly, it represents the basis of acquired therapy resistance, and secondly, it may be one of the major sources of the low level of reproducibility in clinical cancer research. The present review focuses on the heterogeneity of neoplastic disease, both within the primary tumour and between primary tumour and metastases. We discuss different levels of heterogeneity and the current understanding of the phenomenon, as well as imminent developments relevant for clinical research and diagnostic pathology. It is necessary to develop new tools to study heterogeneity and new biomarkers for heterogeneity. Established and new in situ methods will be very useful. In future studies, not only clonal heterogeneity needs to be addressed but also non-clonal phenotypic heterogeneity which might be important for therapy resistance. We also review heterogeneity established in major tumour types, in order to explore potential similarities that might help to define new strategies for targeted therapy.