Characterisation and traceability of extra virgin olive oil and table olive of Azapa variety marketed in Chile using Microsatellite Molecular Markers / Caracterización y trazabilidad de aceite de oliva virgen extra y aceituna de mesa de la variedad Azapa comercializados en Chile mediante marcadores moleculares microsatélites

Chile has two certified origin olive products: Extra-Virgin Olive Oil (EVOO) from Huasco valley and the Azapa variety table olive from the Azapa valley. However, efficient methodologies are needed to determine the varieties and raw materials involved in the end products. In this study, we assessed the size of alleles from ten microsatellites in 20 EVOOs and in leaves and fruits of 16 olive varieties cultivated in Chile to authenticate their origins. The identification of varieties relied on specific allele sizes derived from microsatellites markers UDO99-011 and DCA18-M found in leaves and fruit mesocarp. While most Chilean single-variety EVOOs matched the variety declared on the label, inconsistencies were observed in single-variety EVOOs containing multiple varieties. Our findings confirm that microsatellites serve as a valuable as diagnostic tools for ensuring the quality control of Geographical Indication certification for Azapa olives and EVOO with Designation of Origin from Huasco.

Chile cuenta con dos productos de oliva de origen certificado: El aceite de oliva virgen extra (AOVE) del valle del Huasco y la aceituna de mesa de la variedad Azapa del valle de Azapa. Sin embargo, se necesitan metodologías eficientes para determinar las variedades y materias primas involucradas en los productos finales. En este estudio, evaluamos el tamaño de los alelos de diez microsatélites en 20 AOVEs y en hojas y frutos de 16 variedades de aceituna cultivadas en Chile para autentificar sus orígenes. La identificación de las variedades se basó en los tamaños alélicos específicos derivados de los marcadores microsatélites UDO99-011 y DCA18-M encontrados en las hojas y el mesocarpio de los frutos. Aunque la mayoría de los AOVEs chilenos monovarietales coincidían con la variedad declarada en la etiqueta, se observaron incoherencias en los AOVEs monovarietales que contenían múltiples variedades. Nuestros hallazgos confirman que los microsatélites sirven como valiosas herramientas de diagnóstico para asegurar el control de calidad de la certificación de Indicación Geográfica para aceitunas de Azapa y AOVE con Denominación de Origen de Huasco.

Correlation between NGS panel-based mutation results and clinical information in colorectal cancer patients.

Early mutation identification guides patients with colorectal cancer (CRC) toward targeted therapies. In the present study, 414 patients with CRC were enrolled, and amplicon-based targeted next-generation sequencing (NGS) was then performed to detect genomic alterations within the 73 cancer-related genes in the OncoAim panel. The overall mutation rate was 91.5 % (379/414). Gene mutations were detected in 38/73 genes tested. The most frequently mutated genes were TP53 (60.9 %), KRAS (46.6 %), APC (30.4 %), PIK3CA (15.9 %), FBXW7 (8.2 %), SMAD4 (6.8 %), BRAF (6.5 %), and NRAS (3.9 %). Compared with the wild type, TP53 mutations were associated with low microsatellite instability/microsatellite stability (MSI-L/MSS) (P = 0.007), tumor location (P = 0.043), and histological grade (P = 0.0009); KRAS mutations were associated with female gender (P = 0.026), distant metastasis (P = 0.023), TNM stage (P = 0.013), and histological grade (P = 0.004); APC mutations were associated with patients <64 years of age at diagnosis (P = 0.04); PIK3CA mutations were associated with tumor location (P = 4.97e-06) and female gender (P = 0.018); SMAD4 mutations were associated with tumor location (P = 0.033); BRAF mutations were associated with high MSI (MSI-H; P = 6.968e-07), tumor location (P = 1.58e-06), and histological grade (P = 0.04). Mutations in 164 individuals were found to be pathogenic or likely pathogenic. A total of 26 patients harbored MSI-H tumors and they all had at least one detected gene mutation. Mutated genes were enriched in signaling pathways associated with CRC. The present findings have important implications for improving the personalized treatment of patients with CRC in China.

Microsatellite instability and mismatch repair protein deficiency: equal predictive markers?

Current clinical guidelines recommend mismatch repair (MMR) protein immunohistochemistry (IHC) or molecular microsatellite instability (MSI) tests as predictive markers of immunotherapies. Most of the pathological guidelines consider MMR protein IHC as the gold standard test to identify cancers with MMR deficiency and recommend molecular MSI tests only in special circumstances or to screen for Lynch syndrome. However, there are data in the literature which suggest that the two test types may not be equal. For example, molecular epidemiology studies reported different rates of deficient MMR (dMMR) and MSI in various cancer types. Additionally, direct comparisons of the two tests revealed relatively frequent discrepancies between MMR IHC and MSI tests, especially in non-colorectal and non-endometrial cancers and in cases with unusual dMMR phenotypes. There are also scattered clinical data showing that the efficacy of immune checkpoint inhibitors is different if the patient selection was based on dMMR versus MSI status of the cancers. All these observations question the current dogma that dMMR phenotype and genetic MSI status are equal predictive markers of the immunotherapies.

Molecular insights into clinical trials for immune checkpoint inhibitors in colorectal cancer: Unravelling challenges and future directions.

Colorectal cancer (CRC) is a complex disease with diverse etiologies and clinical outcomes. Despite considerable progress in development of CRC therapeutics, challenges remain regarding the diagnosis and management of advanced stage metastatic CRC (mCRC). In particular, the five-year survival rate is very low since mCRC is currently rarely curable. Over the past decade, cancer treatment has significantly improved with the introduction of cancer immunotherapies, specifically immune checkpoint inhibitors. Therapies aimed at blocking immune checkpoints such as PD-1, PD-L1, and CTLA-4 target inhibitory pathways of the immune system, and thereby enhance anti-tumor immunity. These therapies thus have shown promising results in many clinical trials alone or in combination. The efficacy and safety of immunotherapy, either alone or in combination with CRC, have been investigated in several clinical trials. Clinical trials, including KEYNOTE-164 and CheckMate 142, have led to Food and Drug Administration approval of the PD-1 inhibitors pembrolizumab and nivolumab, respectively, for the treatment of patients with unresectable or metastatic microsatellite instability-high or deficient mismatch repair CRC. Unfortunately, these drugs benefit only a small percentage of patients, with the benefits of immunotherapy remaining elusive for the vast majority of CRC patients. To this end, primary and secondary resistance to immunotherapy remains a significant issue, and further research is necessary to optimize the use of immunotherapy in CRC and identify biomarkers to predict the response. This review provides a comprehensive overview of the clinical trials involving immune checkpoint inhibitors in CRC. The underlying rationale, challenges faced, and potential future steps to improve the prognosis and enhance the likelihood of successful trials in this field are discussed.

Effector Function Characteristics of Exhausted CD8+ T-cell in Microsatellite Stable and Unstable Gastric Cancer.

Purpose: Gastric cancer exhibits molecular heterogeneity, with the microsatellite instability high (MSI-H) subtype drawing attention for its distinct features. Despite a higher survival rate, MSI-H gastric cancer lack significant benefits from conventional chemotherapy. The immune checkpoint inhibitors (ICIs), presents a potential avenue, but a deeper understanding of the tumor immune microenvironment of MSI-H gastric cancer is essential. Materials and Methods: We explored the molecular characteristics of CD8+ T cell subtypes in three MSI-H and three microsatellite stable (MSS) gastric cancer samples using single-cell RNA sequencing and spatial transcriptome analysis. Results: In MSI-H gastric cancer, significantly higher proportions of effector memory T cell (Tem), exhausted T cell (Tex), proliferative exhausted T cell (pTex), and proliferative T cell were observed, while MSS gastric cancer exhibited significantly higher proportions of mucosal-associated invariant T (MAIT) cell and NKT cell. In MSI-H gastric cancer, Tex and pTex exhibited a significant upregulation of the exhaustion marker LAG3, as well as elevated expression of effector function markers such as IFNG, GZMB, GZMH, and GZMK, compared to those in MSS gastric cancer. The IFN-γ signaling pathway of Tex and pTex was retained compared to those of MSS gastric cancer. The spatial transcriptome analysis demonstrates the IFN-γ signaling pathway between neighboring Tex and malignant cell, showcasing a significantly elevated interaction in MSI-H gastric cancer. Conclusion: Our study reveals novel finding indicating that IFN-γ signaling pathway is retained in Tex and pTex of MSI-H gastric cancer, offering a comprehensive perspective for future investigations into immunotherapy for gastric cancer.

Multiple-matrix metabolomics analysis for the distinct detection of colorectal cancer and adenoma.

OBJECTIVES: Although colorectal cancer (CRC) is the leading cause of cancer-related morbidity and mortality, current diagnostic tests for early-stage CRC and colorectal adenoma (CRA) are suboptimal. Therefore, there is an urgent need to explore less invasive screening procedures for CRC and CRA diagnosis. METHODS: Untargeted gas chromatography-mass spectrometry (GC-MS) metabolic profiling approach was applied to identify candidate metabolites. We performed metabolomics profiling on plasma samples from 412 subjects including 200 CRC patients, 160 CRA patients and 52 normal controls (NC). Among these patients, 45 CRC patients, 152 CRA patients and 50 normal controls had their fecal samples tested simultaneously. RESULTS: Differential metabolites were screened in the adenoma-carcinoma sequence. Three diagnostic models were further developed to identify cancer group, cancer stage, and cancer microsatellite status using those significant metabolites. The three-metabolite-only classifiers used to distinguish the cancer group always keeps the area under the receiver operating characteristic curve (AUC) greater than 0.7. The AUC performance of the classifiers applied to discriminate CRC stage is generally greater than 0.8, and the classifiers used to distinguish microsatellite status of CRC is greater than 0.9. CONCLUSION: This finding highlights potential early-driver metabolites in CRA and early-stage CRC. We also find potential metabolic markers for discriminating the microsatellite state of CRC. Our study and diagnostic model have potential applications for non-invasive CRC and CRA detection.

Synchronous Gastric and Colonic Adenocarcinoma: A Case Report With its Molecular Implications.

Multiple primary tumors are rare but their incidence is increasing nowadays with advancements in diagnostic methods and the extended survival of individuals previously treated for malignancies. However, synchronous occurrence of gastric cancer (GC) and colonic cancer (CC) is a rare entity. A 41-year-old male came with complaints of epigastric pain associated with anorexia, rapid weight loss, and occasional constipation. Contrast-enhanced computed tomography (CECT) of the abdomen and pelvis reported mucosal thickening in the antrum, likely GC with circumferential wall thickening of the transverse colon with pericolic fat stranding suggestive of CC. Upper gastrointestinal endoscopy and colonoscopy were also done and a biopsy was taken from representative sites, which confirmed malignancy. He completed three cycles of chemotherapy preoperatively and underwent subtotal gastrectomy, D2 lymphadenectomy, gastrojejunostomy, jejunojejunostomy, and transverse colectomy simultaneously. Histopathological examination confirmed moderately differentiated gastric adenocarcinoma penetrating into the subserosa and well-differentiated colonic adenocarcinoma invading the muscularis propria. Immunohistochemical analysis of mismatch repair (MMR) proteins was done to determine the association with hereditary nonpolyposis colorectal cancer syndrome (HNPCC) or Lynch syndrome. The patient underwent postoperative chemotherapy along with immunotherapy. To conclude, synchronous occurrence of primary GC and primary CC with similar MMR protein expression in immunohistochemistry is an uncommon entity.

Preoperative prediction of microsatellite instability status in colorectal cancer based on a multiphasic enhanced CT radiomics nomogram model.

BACKGROUND: To investigate the value of a nomogram model based on the combination of clinical-CT features and multiphasic enhanced CT radiomics for the preoperative prediction of the microsatellite instability (MSI) status in colorectal cancer (CRC) patients. METHODS: A total of 347 patients with a pathological diagnosis of colorectal adenocarcinoma, including 276 microsatellite stabilized (MSS) patients and 71 MSI patients (243 training and 104 testing), were included. Univariate and multivariate regression analyses were used to identify the clinical-CT features of CRC patients linked with MSI status to build a clinical model. Radiomics features were extracted from arterial phase (AP), venous phase (VP), and delayed phase (DP) CT images. Different radiomics models for the single phase and multiphase (three-phase combination) were developed to determine the optimal phase. A nomogram model that combines clinical-CT features and the optimal phasic radscore was also created. RESULTS: Platelet (PLT), systemic immune inflammation index (SII), tumour location, enhancement pattern, and AP contrast ratio (ACR) were independent predictors of MSI status in CRC patients. Among the AP, VP, DP, and three-phase combination models, the three-phase combination model was selected as the best radiomics model. The best MSI prediction efficacy was demonstrated by the nomogram model built from the combination of clinical-CT features and the three-phase combination model, with AUCs of 0.894 and 0.839 in the training and testing datasets, respectively. CONCLUSION: The nomogram model based on the combination of clinical-CT features and three-phase combination radiomics features can be used as an auxiliary tool for the preoperative prediction of the MSI status in CRC patients.

Microsatellite instability evaluation by a novel PCR-based 8-loci test kit in colorectal cancer.

Microsatellite instability (MSI) assessment is strongly recommended for colorectal cancer patients, as MSI status is crucial in determining optimal treatment and predicting prognosis. This study evaluated the reliability and accuracy of a novel polymerase chain reaction (PCR)-based 8-loci MSI test kit, a rapid test kit designed to detect MSI, by comparing its performance with immunohistochemistry (IHC) and the National Cancer Institute (NCI) 2B3D Panel. MSI status was determined in 186 formalin-fixed paraffin-embedded (FFPE) colorectal cancer tissue samples with known mismatch repair (MMR) status by IHC using the novel PCR-based 8-loci MSI test kit. Additionally, the consistency between the NCI 2B3D Panel and the novel PCR-based 8-loci panel was compared using 69 FFPE tumor tissues paired with adjacent non-cancerous tissue. The novel PCR-based 8-loci MSI test kit and IHC demonstrated high concordance (overall agreement: 97.8%). However, four samples displayed discordant results, exhibiting MMR deficiency using IHC and microsatellite stability using the novel PCR-based 8-loci MSI test kit. Of the 69 samples reanalyzed using the NCI 2B3D Panel, high concordance with the novel PCR-based 8-loci MSI test kit was observed in 67 of 69 cases (overall agreement: 97.1%). The novel PCR-based 8-loci MSI test kit is a rapid and reliable tool for accurately detecting MSI status in colorectal cancer.

Ancestry and genetic structure of resident and anadromous rainbow trout (Oncorhynchus mykiss) in Argentina.

Since the first introduction from North America more than a century ago, rainbow trout (Oncorhynchus mykiss) have rapidly established self-sustaining populations in major river basins of Patagonia. Many generations later, only the freshwater resident life history is expressed in the Chubut and Negro rivers of northern Argentinian Patagonia, whereas both the resident and anadromous life histories are found in the Santa Cruz River of southern Argentina. Despite previous studies that have tried to identify the sources of these introduced populations, uncertainty still exists. Here we combined data from many single-nucleotide polymorphisms and microsatellite loci in O. mykiss populations from Argentina and North America to evaluate putative source populations, gene flow between Argentinian river basins, and genetic diversity differences between Argentinian and North American populations. We found that populations from northern and southern Patagonia are highly differentiated and have limited gene flow between them. Phylogeographic analysis also confirmed that they have separate origins, with the northern populations most closely related to the domesticated rainbow trout strains that are raised worldwide and the Santa Cruz River populations most closely related to North American populations from California and Oregon that have an anadromous component. In addition, fish with different life histories in the Santa Cruz River were found to constitute a single interbreeding population. No evidence was found of reduced genetic variation in introduced rainbow trout, suggesting multiple contributing sources. In spite of these advances in understanding, significant questions remain regarding the origins and evolution of the introduced O. mykiss in Patagonia.

Molecular classification and intratumoral heterogeneity of gastric adenocarcinoma.

Gastric cancers frequently harbor striking histological complexity and diversity between lesions as well as within single lesions, known as inter- and intratumoral heterogeneity, respectively. The latest World Health Organization Classification of Tumors designated more than 30 histological subtypes for gastric epithelial tumors, assigning 12 subtypes for gastric adenocarcinoma (GAD). Meanwhile, recent advances in genome-wide analyses have provided molecular aspects to the histological classification of GAD, and consequently revealed different molecular traits underlying these histological subtypes. Moreover, accumulating knowledge of comprehensive molecular profiles has led to establishing molecular classifications of GAD, which are often associated with clinical biomarkers for therapeutics and prognosis. However, most of our knowledge of GAD molecular profiles is based on inter-tumoral heterogeneity, and the molecular profiles underlying intratumoral heterogeneity are yet to be determined. In this review, recently established molecular classifications of GAD are introduced in the aspect of pathological diagnosis and are discussed in the context of intratumoral heterogeneity.

Pembrolizumab Plus Binimetinib With or Without Chemotherapy for MSS/pMMR Metastatic Colorectal Cancer: Outcomes From KEYNOTE-651 Cohorts A, C, and E.

BACKGROUND: Cohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary. RESULTS: In cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E. CONCLUSION: Per DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.

Successful pembrolizumab treatment for microsatellite instability-high thymoma: A case report.

Microsatellite instability (MSI) is a valuable biomarker for immune checkpoint inhibitors. We report the first case of MSI-high thymoma successfully treated with pembrolizumab. This patient had pleural dissemination and was treated with two cytotoxic chemotherapy regimens including carboplatin and paclitaxel combination therapy and pemetrexed, which did not have the desired effect. Because MSI status was high by using the surgical specimen, pembrolizumab was administered as 3rd line chemotherapy. After three courses, the pleural lesions dramatically shrunk, which confirmed a partial response. Although MSI-high thymoma is rare, our results suggest the necessity to evaluate MSI status in patients with thymoma.

Genetic Structure and Diversity of Hatchery and Wild Populations of Yellow Catfish Tachysurus fulvidraco (Siluriformes: Bagridae) from Korea.

Yellow catfish Tachysurus fulvidraco is an important commercial fish species in South Korea. However, due to their current declines in its distribution area and population size, it is being released from hatchery populations into wild populations. Hatchery populations also produced from wild broodstocks are used for its captive breeding. We reported 15 new microsatellite DNA markers of T. fulvidraco to identify the genetic diversity and structure of its hatchery and wild populations, providing baseline data for useful resource development strategies. The observed heterozygosity of the hatchery populations ranged from 0.816 to 0.873, and that of the wild populations ranged from 0.771 to 0.840. Their inbreeding coefficient ranged from -0.078 to 0.024. All populations experienced a bottleneck (p < 0.05), with effective population sizes ranging from 21 to infinity. Their gene structure was divided into two groups with STRUCTURE results of K = 2. It was confirmed that each hatchery population originated from a different wild population. This study provides genetic information necessary for the future development and conservation of fishery resources for T. fulvidraco.

Agnostic Administration of Targeted Anticancer Drugs: Looking for a Balance between Hype and Caution.

Many tumors have well-defined vulnerabilities, thus potentially allowing highly specific and effective treatment. There is a spectrum of actionable genetic alterations which are shared across various tumor types and, therefore, can be targeted by a given drug irrespective of tumor histology. Several agnostic drug-target matches have already been approved for clinical use, e.g., immune therapy for tumors with microsatellite instability (MSI) and/or high tumor mutation burden (TMB), NTRK1-3 and RET inhibitors for cancers carrying rearrangements in these kinases, and dabrafenib plus trametinib for BRAF V600E mutated malignancies. Multiple lines of evidence suggest that this histology-independent approach is also reasonable for tumors carrying ALK and ROS1 translocations, biallelic BRCA1/2 inactivation and/or homologous recombination deficiency (HRD), strong HER2 amplification/overexpression coupled with the absence of other MAPK pathway-activating mutations, etc. On the other hand, some well-known targets are not agnostic: for example, PD-L1 expression is predictive for the efficacy of PD-L1/PD1 inhibitors only in some but not all cancer types. Unfortunately, the individual probability of finding a druggable target in a given tumor is relatively low, even with the use of comprehensive next-generation sequencing (NGS) assays. Nevertheless, the rapidly growing utilization of NGS will significantly increase the number of patients with highly unusual or exceptionally rare tumor-target combinations. Clinical trials may provide only a framework for treatment attitudes, while the decisions for individual patients usually require case-by-case consideration of the probability of deriving benefit from agnostic versus standard therapy, drug availability, associated costs, and other circumstances. The existing format of data dissemination may not be optimal for agnostic cancer medicine, as conventional scientific journals are understandably biased towards the publication of positive findings and usually discourage the submission of case reports. Despite all the limitations and concerns, histology-independent drug-target matching is certainly feasible and, therefore, will be increasingly utilized in the future.

Precision Medicine in the Era of Genetic Testing: Microsatellite Instability Evolved.

The recognized importance of microsatellite instability (MSI) in cancer has evolved considerably in the past 30 years. From its beginnings as a molecular predictor for Lynch syndrome, MSI first transitioned to a universal screening test in all colorectal and endometrial cancers, substantially increasing the identification of patients with Lynch syndrome among cancer patients. More recently, MSI has been shown to be a powerful biomarker of response to immune checkpoint blockade therapy across a diversity of tumor types, and in 2017 was granted Food and Drug Administration approval as the first tumor histology-agnostic biomarker for a cancer therapy. Focusing on colorectal cancer specifically, immune checkpoint blockade therapy has been shown to be highly effective in the treatment of both MSI-high (MSI-H) colon and rectal cancer, with data increasingly suggesting an early role for immune checkpoint blockade therapy in MSI-H colorectal tumors in the neoadjuvant setting, with the potential to avoid more toxic and morbid approaches using traditional chemotherapy, radiation therapy, and surgery. The success of MSI as an immune checkpoint blockade target has inspired ongoing vigorous research to identify new similar targets for immune checkpoint blockade therapy that may help to one day expand the reach of this revolutionary cancer therapy to a wider swath of patients and indications.

Microsatellite instability is highly prevalent in older patients with colorectal cancer.

Background: Clinical guidelines suggest screening of colorectal cancer (CRC) for microsatellite instability (MSI). However, microsatellite instability-high (MSI-H) CRC is not rare in older patients. This study aimed to investigate the prevalence of MSI-H CRC in an unselected population in an age-based manner. Material and methods: A retrospective analysis of data from patients undergoing radical surgery for CRC was performed. Only cases with results from MSI testing using immunochemistry (IHC) were analyzed. Age-based analyses were performed using two cut-off ages: 50 years. as stated in Amsterdam II guidelines, and 60 years. as outlined in the revised Bethesda criteria. Results: The study population included 343 (146 female and 197 male) patients with a median age of 70 years (range 21-90 years). The prevalence of MSI-H tumors in the entire cohort was 18.7%. The prevalence of MSI-H CRC was 22.5% in the group ≤50 years vs. 18.2% in the group >50 years using the age limit in the Amsterdam II guidelines. MSI-H CRC was present in 12.6% of the group aged ≤60 years compared to 20.6% in the control group >60 years. Conclusion: MSI screening of CRC based on age alone is associated with negative selection of a relevant number of cases. MSI-H CRC is also common in elderly patients, who may be negatively selected secondary to an age-based screening algorithm. Following the results of this study, screening based on clinical criteria should be omitted in favor of systematic screening as is already internationally practiced.

Genetic variation and structure of endemic and endangered wild celery (Kelussia odoratissima Mozaff.) quantified using novel microsatellite markers developed by next-generation sequencing.

Kelussia odoratissima Mozaff. (Apiaceae) is a native plant that has been traditionally consumed in Iran's food and pharmaceutical industries. Overharvesting of the taxon, especially at the beginning of the growing season, due to its considerable medicinal and economic value, is believed to be the main reason for the extirpating of this plant. The consequences of the severe anthropogenic impacts on the genetic diversity of populations are poorly known. In order to investigate the level of genetic variation and patterns of the genetic structure of K. odoratissima, we developed novel microsatellite markers using the 454 Roche next-generation sequencing (NGS) platform for the first time. Out of 1,165 microsatellite markers bioinformatically confirmed, twenty-five were tested, of which 23 were used to screen genetic variation across 12 natural populations. Our results showed that the average number of alleles per locus and the polymorphic information content (PIC) were 10.87 (range 7 to 27), and 0.81 (range 0.67 to 0.94), respectively. The mean observed and expected heterozygosities (± SD) across all populations were 0.80 ± 0.31 and 0.72 ± 0.14, respectively. The average pairwise FST among the populations was 0.37 (range 0.04 to 0.81). Bayesian and distance-based clustering, and principal coordinate analyses revealed at least four major genetic clusters. Although high level of structure can be explained by landscape topography and geographic distance, presence of admixed populations can be associated to seed or pollen dispersal. Contrary to expectations, the high level of genetic variation and lack of inbreeding suggest that overexploitation has not yet significantly purged the allelic variability within the natural populations in protected areas.

KMT2C mutation as a predictor of immunotherapeutic efficacy in colorectal cancer.

Immunotherapy had shown good antitumor activity in a variety of solid tumors, but low benefit in CRC, so there was an urgent need to explore new biomarkers. We evaluated the role of KMT2C using publicly available data from the Cancer Genome Atlas (TCGA) and Memorial Sloan Kettering Cancer Center (MSKCC). In addition, further analysis was performed in an internal cohort. Moreover, the mutant profiles of KMT2C was analyzed in a large CRC cohort. The relationship between clinical pathologic features and KMT2C were analyzed with using the two-sided chi-squared test or the Fisher exact test. Clinicopathologic characteristics associated with overall survival using Cox regression and the Kaplan-Meier method. We found that KMT2C-mutated CRC patients in the immunotherapy cohort had significantly improved OS compared with KMT2C WT patients (P = 0.013). However, this phenomenon did not exist in non-immunotherapy cohort. Our cohort validated the value of KMT2C mutations in predicting better clinical outcomes, including ORR (P < 0.0001) and OS (P = 0.010). Meanwhile, KMT2C mutation was associated with higher tumor mutation burden, MSI score, higher levels of immune-associated T cells, neutrophil, and M1-type macrophages. Our study suggested that KMT2C mutation might be a potential positive predictor for CRC immunotherapy.

Prognostic and predictive impact of sex in locally advanced microsatellite instability high gastric or gastroesophageal junction cancer: An individual patient data pooled analysis of randomized clinical trials.

BACKGROUND: Surgery plus peri-operative/adjuvant chemotherapy is the standard of care for locally advanced GC/GEJC, though with unsatisfactory results. dMMR/MSI-high tumors have better prognosis and scant benefit from chemotherapy as compared to pMMR/MSS ones. The differential outcome of therapies in terms of safety and efficacy according to sex is still debated in GC/GEJC patients. METHODS: We previously performed an individual patient data pooled analysis of MAGIC, CLASSIC, ITACA-S, and ARTIST trials including GC/GEJC patients treated with surgery alone or surgery plus peri-operative/adjuvant chemotherapy to assess the value of MSI status. We performed a secondary analysis investigating the prognostic and predictive role of sex (female versus male) in the pooled analysis dataset in the overall population and patients stratified for MSI status (MSI-high versus MSS/MSI-low). Disease-free (DFS) and overall survival (OS) were calculated. RESULTS: Patients with MSI-high tumors had improved survival as compared to MSS/MSI-low ones irrespective of sex, whereas in those with MSS/MSI-low tumors, females had numerically longer OS and DFS (5-year OS was 63.2% versus 57.6%, HR 0.842; p = 0.058, and 5-year DFS was 55.8% versus 50.8%, HR 0.850; p = 0.0504 in female versus male patients). The numerical difference for the detrimental effect of chemotherapy in MSI-high GC was higher in females than males, while the significant benefit of chemotherapy over surgery alone was confirmed in MSS/MSI-low GC irrespective of sex. CONCLUSIONS: This pooled analysis including four randomized trials highlights a relevant impact of sex in the prognosis and treatment efficacy of MSI-high and MSS/MSI-low non-metastatic GC/GEJC.