•Molecular testing determines appropriate targeted therapies for advanced NSCLC.•Country-specific differences exist in molecular testing availability across Europe.•Molecular tumour board and reflex ...molecular testing strategies are desirable.•Next-generation sequencing permits comprehensive molecular testing.•Cell-free DNA-based analysis facilitates re-testing to guide subsequent treatment.
The discovery of oncogenic driver mutations rendering non-small cell lung cancer (NSCLC) targetable by small-molecule inhibitors, and the development of immunotherapies, have revolutionised NSCLC treatment. Today, instead of non-selective chemotherapies, all patients with advanced NSCLC eligible for treatment (and increasing numbers with earlier, less extensive disease) require fast and comprehensive screening of biomarkers for first-line patient selection for targeted therapy, chemotherapy, or immunotherapy (with or without chemotherapy). To avoid unnecessary re-biopsies, biomarker screening before first-line treatment should also include markers that are actionable from second-line onwards; PD-L1 expression testing is also mandatory before initiating treatment.
Population differences exist in the frequency of oncogenic driver mutations: EGFR mutations are more frequent in Asia than Europe, whereas the converse is true for KRAS mutations. In addition to approved first-line therapies, a number of emerging therapies are being investigated in clinical trials. Guidelines for biomarker testing vary by country, with the number of actionable targets and the requirement for extensive molecular screening strategies expected to increase. To meet diagnostic demands, rapid screening technologies for single-driver mutations have been implemented. Improvements in DNA- and RNA-based next-generation sequencing technologies enable analysis of a group of genes in one assay; however, turnaround times remain relatively long. Consequently, rapid screening technologies are being implemented alongside next-generation sequencing.
Further challenges in the evolving landscape of biomarker testing in NSCLC are actionable primary and secondary resistance mechanisms to targeted therapies. Therefore, comprehensive testing on re-biopsies, collected at the time of disease progression, in combination with testing of circulating tumour DNA may provide important information to guide second- or third-line therapies. Furthermore, longitudinal biomarker testing can provide insights into tumour evolution and heterogeneity during the course of the disease. We summarise best practice strategies for Europe in the changing landscape of biomarker testing at diagnosis and during treatment.
The HMG-box transcription factor Sox9 is expressed in the intestinal epithelium, specifically, in stem/ progenitor cells and in Paneth cells. Sox9 expression requires an active β-catenin-Tcf complex, ...the transcriptional effector of the Wnt pathway. This pathway is critical for numerous aspects of the intestinal epithelium physiopathology, but processes that specify the cell response to such multipotential signals still remain to be identified. We inactivated the Sox9 gene in the intestinal epithelium to analyze its physiological function. Sox9 inactivation affected differentiation throughout the intestinal epithelium, with a disappearance of Paneth cells and a decrease of the goblet cell lineage. Additionally, the morphology of the colon epithelium was severely altered. We detected general hyperplasia and local crypt dysplasia in the intestine, and Wnt pathway target genes were up-regulated. These results highlight the central position of Sox9 as both a transcriptional target and a regulator of the Wnt pathway in the regulation of intestinal epithelium homeostasis.
Carcinoma progression is linked to a partially dedifferentiated epithelial cell phenotype. As previously suggested, this regulation could involve transcription factors, Snail and Slug, known to ...promote epithelial-mesenchymal transitions during development. Here, we investigate the role of Snail and Slug in human breast cancer progression.
We analyzed Snail, Slug, and E-cadherin RNA expression levels and protein localization in large numbers of transformed cell lines and breast carcinomas, examined the correlation with tumor histologic features, and described, at the cellular level, Snail and Slug localization in carcinomas using combined in situ hybridization and immunolocalization.
In contrast with transformed cell lines, Slug was found to colocalize with E-cadherin at the cellular level in normal mammary epithelial cells and all tested carcinomas. Snail also colocalized at the cellular level with E-cadherin in tumors expressing high levels of Snail RNA. In addition, Snail was significantly expressed in tumor stroma, varying with tumors. Slug and Snail genes were significantly overexpressed in tumors associated with lymph node metastasis. Finally, the presence of semidifferentiated tubules within ductal carcinomas was linked to Slug expression levels similar to or above normal breast samples.
These results suggest that Snail or Slug expression in carcinoma cells does not generally preclude significant E-cadherin expression. They emphasize a link between Snail, Slug, and lymph node metastasis in a large sampling of mammary carcinomas, and suggest a role for Slug in the maintenance of semidifferentiated structures. Snail and Slug proteins seem to support distinct tumor invasion modes and could provide new therapeutic targets.
Abstract Ovarian carcinoma is the most lethal gynaecologic malignancy. Despite wide initial sensibility to chemotherapy especially to platinum-based regimens, the vast majority of patients with ...advanced stages of the disease develop recurrences and subsequent resistance to treatments. Ovarian cancer is actually considered as a heterogeneous disease at the clinical, histological and molecular level. In this review, the mechanisms of intrinsic sensitivity or resistance to treatment, especially to platinum-based chemotherapy are considered with particular reference to the significance of tumour heterogeneity. The molecular features involved in acquired resistance are reviewed and the current hypotheses are discussed. In particular, potential disruptions of the DNA reparation pathways are highlighted.
To better understand the relationship between tumor-host interactions and the efficacy of chemotherapy, we have developed an analytical approach to quantify several biological processes observed in ...gene expression data sets. We tested the approach on tumor biopsies from individuals with estrogen receptor-negative breast cancer treated with chemotherapy. We report that increased stromal gene expression predicts resistance to preoperative chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) in subjects in the EORTC 10994/BIG 00-01 trial. The predictive value of the stromal signature was successfully validated in two independent cohorts of subjects who received chemotherapy but not in an untreated control group, indicating that the signature is predictive rather than prognostic. The genes in the signature are expressed in reactive stroma, according to reanalysis of data from microdissected breast tumor samples. These findings identify a previously undescribed resistance mechanism to FEC treatment and suggest that antistromal agents may offer new ways to overcome resistance to chemotherapy.
Primary resistance to immune checkpoint inhibitors is observed in 10% to 40% of patients with metastatic colorectal cancer (mCRC) displaying microsatellite instability (MSI) or defective mismatch ...repair (dMMR).
To investigate possible mechanisms underlying primary resistance to immune checkpoint inhibitors of mCRC displaying MSI or dMMR.
This post hoc analysis of a single-center, prospective cohort included 38 patients with mCRC diagnosed as MSI or dMMR by local laboratories and entered into trials of immune checkpoint inhibitors between January 1, 2015, and December 31, 2016. The accuracy of MSI or dMMR status was also assessed in a retrospective cohort comprising 93 cases of mCRC that were diagnosed as MSI or dMMR between January 1, 1998, and December 31, 2016, in 6 French hospitals. Primary resistance of mCRC was defined as progressive disease according to Response Evaluation Criteria in Solid Tumors criteria, 6 to 8 weeks after initiation of immune checkpoint inhibitors, without pseudo-progression. All tumor samples were reassessed for dMMR status using immunohistochemistry with antibodies directed against MLH1, MSH2, MSH6, and PMS2, and for MSI using polymerase chain reaction with pentaplex markers and with the HSP110 T17 (HT17) repeat.
The primary outcome was positive predictive value.
Among the 38 patients (15 women and 23 men; mean SD age, 55.6 13.7 years) in the study with mCRC displaying MSI or dMMR, primary resistance to immune checkpoint inhibitors was observed in 5 individuals (13%). Reassessment of the status of MSI or dMMR revealed that 3 (60%) of these 5 resistant tumors were microsatellite stable or displayed proficient mismatch repair. The positive predictive value of MSI or dMMR status assessed by local laboratories was therefore 92.1% (95% CI, 78.5%-98.0%). In the retrospective cohort of 93 patients (44 women and 49 men; mean SD age, 56.8 18.3 years) without immune checkpoint inhibitor treatment, misdiagnosis of the MSI or dMMR status by local assessment was 10% (n = 9), with a positive predictive value of 90.3% (95% CI, 82.4%-95.0%). Testing for MSI with the HT17 assay confirmed the MSI or dMMR status in 2 of 4 cases showing discrepant results between immunohistochemistry and pentaplex polymerase chain reaction (ie, dMMR but microsatellite stable).
Primary resistance of mCRC displaying MSI or dMMR to immune checkpoint inhibitors is due mainly to misdiagnosis of their MSI or dMMR status. Larger studies are required to confirm these findings. Microsatellite instability or dMMR status should be tested routinely using both immunohistochemistry and polymerase chain reaction methods prior to treatment with immune checkpoint inhibitors.
Objective
The aim of this study was to assess the safety and efficacy of extended liver venous deprivation (eLVD), i.e. combination of right portal vein embolisation and right (accessory right) and ...middle hepatic vein embolisation before major hepatectomy for future remnant liver (FRL) functional increase.
Methods
eLVD was performed in non-cirrhotic patients referred for major hepatectomy in a context of small FRL (baseline FRL <25% of the total liver volume or FRL function <2.69%/min/m
2
). All patients underwent
99m
Tc-mebrofenin hepatobiliary scintigraphy (HBS) and computed tomographic evaluations.
Results
Ten consecutive patients underwent eLVD before surgery for liver metastases (
n
= 8), Klatskin tumour (
n
= 1) and gallbladder carcinoma (
n
= 1). FRL function increased by 64.3% (range = 28.1-107.5%) at day 21. In patients with serial measurements, maximum FRL function was at day 7 (+65.7 ± 16%). The FRL volume increased by +53.4% at 7 days (+25 ± 8 cc/day). Thirty-one days (range = 22-45 days) after eLVD, 9/10 patients were resected. No post-hepatectomy liver failure was reported. Two grade II and one grade III complications (Dindo-Clavien classification) occurred. No patient died with-in 90 days following surgery.
Conclusions
eLVD is safe and provides a marked and very rapid increase in liver function, unprecedented for an interventional radiology procedure.
Key Points
•
eLVD is safe
•
eLVD provides a marked and very rapid increase in liver function
•
After eLVD, the FRL-F increased by 64.3% (28.1-107.5%) at day 21
•
After eLVD, the maximum FRL-F was obtained at day 7 (+65.7 ± 16%)
•
After eLVD, the FRL volume increased by +53.4% at 7 days (+25 ± 8 cc/day)
The identification of a molecular signature predicting the relapse of tamoxifen-treated primary breast cancers should help the therapeutic management of estrogen receptor-positive cancers.
A series ...of 132 primary tumors from patients who received adjuvant tamoxifen were analyzed for expression profiles at the whole-genome level by 70-mer oligonucleotide microarrays. A supervised analysis was done to identify an expression signature.
We defined a 36-gene signature that correctly classified 78% of patients with relapse and 80% of relapse-free patients (79% accuracy). Using 23 independent tumors, we confirmed the accuracy of the signature (78%) whose relevance was further shown by using published microarray data from 60 tamoxifen-treated patients (63% accuracy). Univariate analysis using the validation set of 83 tumors showed that the 36-gene classifier is more efficient in predicting disease-free survival than the traditional histopathologic prognostic factors and is as effective as the Nottingham Prognostic Index or the "Adjuvant!" software. Multivariate analysis showed that the molecular signature is the only independent prognostic factor. A comparison with several already published signatures demonstrated that the 36-gene signature is among the best to classify tumors from both training and validation sets. Kaplan-Meier analyses emphasized its prognostic power both on the whole cohort of patients and on a subgroup with an intermediate risk of recurrence as defined by the St. Gallen criteria.
This study identifies a molecular signature specifying a subgroup of patients who do not gain benefits from tamoxifen treatment. These patients may therefore be eligible for alternative endocrine therapies and/or chemotherapy.
Cyclin A2 plays a key role in cell cycle regulation. It is essential in embryonic cells and in the hematopoietic lineage yet dispensable in fibroblasts. In this paper, we demonstrate that Cyclin ...A2-depleted cells display a cortical distribution of actin filaments and increased migration. These defects are rescued by restoration of wild-type Cyclin A2, which directly interacts with RhoA, or by a Cyclin A2 mutant unable to associate with Cdk. In vitro, Cyclin A2 potentiates the exchange activity of a RhoA-specific guanine nucleotide exchange factor. Consistent with this, Cyclin A2 depletion enhances migration of fibroblasts and invasiveness of transformed cells via down-regulation of RhoA activity. Moreover, Cyclin A2 expression is lower in metastases relative to primary colon adenocarcinoma in matched human tumors. All together, these data show that Cyclin A2 negatively controls cell motility by promoting RhoA activation, thus demonstrating a novel Cyclin A2 function in cytoskeletal rearrangements and cell migration.
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