Clinicopathological Features of Non-Small Cell Lung Carcinoma with BRAF Mutation.

(1) Background: BRAF mutations affect 4-5% of lung adenocarcinomas. This study aimed to analyze the clinicopathological features of lung carcinomas with BRAF mutations, focusing on V600E vs. non-V600E and the presence of co-mutations. (2) Methods: All BRAF-mutated lung carcinomas were retrieved from a molecular diagnostic unit (the reference unit for four different hospitals). The samples were analyzed using next-generation sequencing. Statistical analyses included log-rank tests for overall survival (OS) and progression-free survival (PFS). (3) Results: In total, 60 BRAF-mutated lung carcinomas were retrieved: 24 (40.0%) with V600E and 36 (60.0%) with non-V600E mutations, and 21 (35.0%) with other co-mutations and 39 (65.0%) with only BRAF mutations. Survival data were available for 54/60 (90.0%) cases. Targeted therapy was documented in 11 cases. Patients with V600E mutations exhibited a better prognosis than patients with non-V600E mutations (p = 0.008 for OS, p = 0.018 for PFS); this was confirmed in PFS (p = 0.036) when considering only patients who received no targeted therapy. Patients with co-mutations displayed no prognostic difference compared to patients carrying only BRAF mutations (p = 0.590 for OS, p = 0.938 for PFS). (4) Conclusions: BRAF-mutated lung carcinomas with V600E (40.0%) had a better prognosis than those without V600E. Concomitant co-mutations (35.0%) did not affect the prognosis.

The role of next-generation sequencing in detecting gene fusions with known and unknown partners: a single-center experience with methodologies' integration.

AIMS: Next-generation sequencing (NGS) is becoming a new gold standard for determining molecular predictive biomarkers. This study aimed to evaluate the reliability of NGS in detecting gene fusions, focusing on comparing gene fusions with known and unknown partners. METHODS: We collected all gene fusions from a consecutive case series using an amplicon-based DNA/RNA NGS platform and subdivided them into two groups: gene fusions with known partners and gene fusions with unknown partners. Gene fusions involving ALK, ROS1 and RET were also examined by immunohistochemistry (IHC) and/or fluorescent in situ hybridization (FISH). RESULTS: Overall, 1174 malignancies underwent NGS analysis. NGS detected gene fusions in 67 cases (5.7%), further subdivided into 43 (64.2%) with known partners and 24 (35.8%) with unknown partners. Gene fusions were predominantly found in non-small cell lung carcinomas (52/67, 77.6%). Gene fusions with known partners frequently involved ALK (20/43, 46.5%) and MET (9/43, 20.9%), while gene fusions with unknown partners mostly involved RET (18/24, 75.0%). FISH/IHC confirmed rearrangement status in most (89.3%) of the gene fusions with known partners, but in only one (4.8%) of the gene fusions with unknown partners, with a significant difference (p < 0.001). In 17 patients undergoing targeted therapy, the log-rank test revealed that the overall survival was higher in the known partner group than in the unknown partner group (p = 0.002). CONCLUSIONS: NGS is a reliable method for detecting gene fusions with known partners, but it is less accurate in identifying gene fusions with unknown partners, for which further analyses (such as FISH) are required.

Effects of a Diet Based on Foods from Symbiotic Agriculture on the Gut Microbiota of Subjects at Risk for Metabolic Syndrome.

Diet is a major driver of gut microbiota variation and plays a role in metabolic disorders, including metabolic syndrome (MS). Mycorrhized foods from symbiotic agriculture (SA) exhibit improved nutritional properties, but potential benefits have never been investigated in humans. We conducted a pilot interventional study on 60 adults with ≥ 1 risk factors for MS, of whom 33 consumed SA-derived fresh foods and 27 received probiotics over 30 days, with a 15-day follow-up. Stool, urine and blood were collected over time to explore changes in gut microbiota, metabolome, and biochemical, inflammatory and immunologic parameters; previous dietary habits were investigated through a validated food-frequency questionnaire. The baseline microbiota showed alterations typical of metabolic disorders, mainly an increase in Coriobacteriaceae and a decrease in health-associated taxa, which were partly reversed after the SA-based diet. Improvements were observed in metabolome, MS presence (two out of six subjects no longer had MS) or components. Changes were more pronounced with less healthy baseline diets. Probiotics had a marginal, not entirely favorable, effect, although one out of three subjects no longer suffered from MS. These findings suggest that improved dietary patterns can modulate the host microbiota and metabolome, counteracting the risk of developing MS.

Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection.

Nowadays, stool DNA can be isolated and analyzed by several methods. The long fragments of DNA in stool can be detected by a qPCR assay, which provides a reliable probability of the presence of pre-neoplastic or neoplastic colorectal lesions. This method, called fluorescence long DNA (FL-DNA), is a fast, non-invasive procedure that is an improvement upon the primary prevention system. This method is based on evaluation of fecal DNA integrity by quantitative amplification of specific targets of genomic DNA. In particular, the evaluation of DNA fragments longer than 200 bp allows for detection of patients with colorectal lesions with very high specificity. However, this system and all currently available stool DNA tests present some general issues that need to be addressed (e.g., the frequency at which tests should be carried out and optimal number of stool samples collected at each timepoint for each individual). However, the main advantage of FL-DNA is the possibility to use it in association with a test currently used in the CRC screening program, known as the immunochemical-based fecal occult blood test (iFOBT). Indeed, both tests can be performed on the same sample, reducing costs and achieving a better prediction of the eventual presence of colorectal lesions.

Shifts of Faecal Microbiota During Sporadic Colorectal Carcinogenesis.

Gut microbiota has been implicated in the etiopathogenesis of colorectal cancer. The development of colorectal cancer is a multistep process by which healthy epithelium slowly develops into preneoplastic lesions, which in turn progress into malignant carcinomas over time. In particular, sporadic colorectal cancers can arise from adenomas (about 85% of cases) or serrated polyps through the "adenoma-carcinoma" or the "serrated polyp-carcinoma" sequences, respectively. In this study, we performed 16 S rRNA gene sequencing of bacterial DNA extracted from faecal samples to compare the microbiota of healthy subjects and patients with different preneoplastic and neoplastic lesions. We identified putative microbial biomarkers associated with stage-specific progression of colorectal cancer. In particular, bacteria belonging to the Firmicutes and Actinobacteria phyla, as well as members of the Lachnospiraceae family, proved to be specific of the faecal microbiota of patients with preneoplastic lesions, including adenomas and hyperplastic polyps. On the other hand, two families of the Proteobacteria phylum, Alcaligeneaceae and Enterobacteriaceae, with Sutterella and Escherichia/Shigella being the most representative genera, appeared to be associated with malignancy. These findings, once confirmed on larger cohorts of patients, can represent an important step towards the development of more effective diagnostic strategies.

Stool DNA Integrity Method for Colorectal Cancer Detection.

Fluorescence long DNA (FL-DNA) is a non-invasive and simple-to-perform stool DNA test. This assay consists of a qualitative and quantitative real-time PCR (RT PCR) analysis. FL-DNA has great potential in colorectal cancer (CRC) lesions detection used alone or in combination with the standard CRC screening tool: immunochemical fecal occult blood test (iFOBT).

What influences preneoplastic colorectal lesion recurrence?

The hypothesis of the local recurrence of preneoplastic lesions was first put forward in the 1950s. Disease recurrence may result from an inherent imbalance in cell proliferation that promotes carcinogenesis in apparently normal mucosa. Our review sheds light on how early preneoplastic lesions could be used to diagnose relapsed preneoplastic and, developing neoplastic lesions. We focus in detail on the clinical-pathological and molecular features of adenoma subtypes and their role in relapsed adenoma and their development into colorectal carcinoma. Moreover, we include the data available on microbiota and its metabolites and their role in recurrence. We strongly believe that a significant improvement could be achieved in colorectal screening by introducing personalized endoscopic surveillance for polyp-bearing patients on the basis of the presence of molecular markers that are predictive of recurrence.

Defining the cutoff value of MGMT gene promoter methylation and its predictive capacity in glioblastoma.

Despite advances in the treatment of glioblastoma (GBM), median survival is 12-15 months. O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status is acknowledged as a predictive marker for temozolomide (TMZ) treatment. When MGMT promoter values fall into a "methylated" range, a better response to chemotherapy is expected. However, a cutoff that discriminates between "methylated" and "unmethylated" status has yet to be defined. We aimed to identify the best cutoff value and to find out whether variability in methylation profiles influences the predictive capacity of MGMT promoter methylation. Data from 105 GBM patients treated between 2008 and 2013 were analyzed. MGMT promoter methylation status was determined by analyzing 10 CpG islands by pyrosequencing. Patients were treated with radiotherapy followed by TMZ. MGMT promoter methylation status was classified into unmethylated 0-9 %, methylated 10-29 % and methylated 30-100 %. Statistical analysis showed that an assumed methylation cutoff of 9 % led to an overestimation of responders. All patients in the 10-29 % methylation group relapsed before the 18-month evaluation. Patients with a methylation status ≥30 % showed a median overall survival of 25.2 months compared to 15.2 months in all other patients, confirming this value as the best methylation cutoff. Despite wide variability among individual profiles, single CpG island analysis did not reveal any correlation between single CpG island methylation values and relapse or death. Specific CpG island methylation status did not influence the predictive value of MGMT. The predictive role of MGMT promoter methylation was maintained only with a cutoff value ≥30 %.

Improved stool DNA integrity method for early colorectal cancer diagnosis.

BACKGROUND: DNA integrity analysis could represent an alternative approach to the early detection of colorectal cancer. Previously, fluorescence long DNA (FL-DNA) in stools was extracted using a manual approach and analyzed by capillary electrophoresis assay (CE FL-DNA). We aimed to improve diagnostic accuracy using a simpler and more standardized method [Real Time PCR FL-DNA (RT FL-DNA)] for the detection of early malignant lesions in a population undergoing colorectal cancer screening. METHODS: From 241 stool samples, DNA was extracted using manual and semiautomatic extraction systems and analyzed using FL-DNA tests by CE and RT assays. The RT FL-DNA approach showed slightly higher sensitivity and specificity compared with the CE FL-DNA method. Furthermore, we compared the RT FL-DNA approach with the iFOBT report. RESULTS: Nonparametric ranking statistics were used to analyze the relationship between the median values of RT FL-DNA and the clinicohistopathologic characteristics. The median values of both variables were significantly higher in patients with cancer than in patients with noncancerous lesions. According to the Fagan nomogram results, the iFOBT and FL-DNA methods provided more accurate diagnostic information and were able to identify subgroups at varying risks of cancer. CONCLUSIONS: The combination of the semiautomatic extraction system and RT FL-DNA analysis improved the quality of DNA extracted from stool samples. IMPACT: RT FL-DNA shows great potential for colorectal cancer diagnosis as it is a reliable and relatively easy analysis to perform on routinely processed stool samples in combination with iFOBT.

Promoter methylation of tumor suppressor genes in pre-neoplastic lesions; potential marker of disease recurrence.

BACKGROUND: Epigenetic alterations of specific genes have been reported to be related to colorectal cancer (CRC) transformation and would also appear to be involved in the early stages of colorectal carcinogenesis. Little data are available on the role of these alterations in determining a different risk of colorectal lesion recurrence. The aim of the present study was to verify whether epigenetic alterations present in pre-neoplastic colorectal lesions detected by colonoscopy can predict disease recurrence. METHODS: A retrospective series of 78 adenomas were collected and classified as low (35) or high-risk (43) for recurrence according to National Comprehensive Cancer Network guidelines. Methylation alterations were analyzed by the methylation-specific multiplex ligation probe assay (MS-MLPA) which is capable of quantifying methylation levels simultaneously in 24 different gene promoters. MS-MLPA results were confirmed by pyrosequencing and immunohistochemistry. RESULTS: Higher levels of methylation were associated with disease recurrence. In particular, MLH1, ATM and FHIT gene promoters were found to be significantly hypermethylated in recurring adenomas. Unconditional logistic regression analysis used to evaluate the relative risk (RR) of recurrence showed that FHIT and MLH1 were independent variables with an RR of 35.30 (95% CI 4.15-300.06, P = 0.001) and 17.68 (95% CI 1.91-163.54, P = 0.011), respectively. CONCLUSIONS: Histopathological classification does not permit an accurate evaluation of the risk of recurrence of colorectal lesions. Conversely, results from our methylation analysis suggest that a classification based on molecular parameters could help to define the mechanisms involved in carcinogenesis and prove an effective method for identifying patients at high risk of recurrence.

Circulating and stool nucleic acid analysis for colorectal cancer diagnosis.

In recent years, the need to identify molecular markers characterized by high sensitivity and specificity in detecting and monitoring early and colorectal cancer lesions has increased. Up to now, none of the markers or panels of markers analyzed have met the rigorous standards required of a screening program. The important discovery of circulating nucleic acids in biological fluids has aroused intense scientific interest because of their usefulness in malignant and non malignant diseases. Over time, their yield and stability have been identified and compared with other "standard" biomarkers. The analysis of circulating DNA from blood and stool is a relatively simple and non-invasive procedure, representing a very attractive marker to detect genetic and epigenetic mutations and to monitor disease progression. A correlation between blood and stool biomarkers could also help to enhance currently available diagnostic approaches. However, various processing and analytic problems need to be resolved before such an approach can be applied in clinical practice.

LOH 19q indicates shorter disease progression-free interval in low-grade oligodendrogliomas with EMP3 methylation.

We previously described a cohort of grade II oligodendroglioma (OII) patients, in whom the loss of heterozygosity (LOH) 19q was present in the subgroup at a higher risk of relapse. In this study, we evaluated the CpG methylation of the putative tumor suppressor epithelial membrane protein 3 (EMP3, 19q13.3) gene promoter in the same OII cohort, to investigate whether a correlation could be found between EMP3 cytogenetic and epigenetic loss and higher risk of relapse. Twenty-three tumor samples from OII patients were collected over a period of 10 years. Seventeen glioblastoma (GBM) samples (2 of which were relapses) were collected from 15 patients. The EMP3, O6-methylguanine methyltransferase (MGMT) and cyclooxygenase 2 (COX2) promoter methylation, evaluated by methylation-specific PCR, and the isocitrate dehydrogenase 1 (IDH1) mutation, identified by sequencing, were compared between the OII and GBM histotypes. The EMP3 promoter methylation was correlated with the analysis of LOH 19q, performed by microsatellite amplification, in OII patients. Disease progression-free interval was evaluated in the OII patients with the EMP3 methylation with either LOH 19q or conserved chromosome 19 arms. The EMP3 and MGMT promoter methylation was more frequent in OII than in GBM patients, and the IDH1 mutation was absent in GBM. The COX2 promoter was unmethylated in both histotypes. Both LOH+/- 19q OII patients showed EMP3 hypermethylation. Concomitant LOH 19q and EMP3 gene promoter methylation was observed in the OII patients at a higher risk of relapse. Our results suggest that a total (cytogenetic and epigenetic) functional loss of both EMP3 alleles accounts for the reduced disease progression-free interval in OII patients. Although the small sample size limits the strength of this study, our results support testing this hypothesis in larger cohorts of patients, considering the methylation of the EMP3 gene promoter together with LOH 19q as an indication for treatment with adjuvant therapy ab initio in order to improve the overall survival of OII patients.

Detection of HER2 and Topo 2 in breast cancers: comparison between MLPA and FISH approaches.

A significant proportion of breast cancers with HER2 amplification show simultaneous amplification or deletion of Topo 2. Amplification of Topo 2 may lead to the overexpression of the Topo 2 protein and ultimately to hypersensitivity to Topo 2 inhibitors. HER2 and Topo 2 gene status in breast cancer patients has been determined in several studies using immunohistochemistry, florescence in situ hybridisation (FISH) and multiplex ligation-dependent probe amplification (MLPA). Although comparisons of FISH and MLPA have been reported for HER2, it is believed that there are no similar studies for Topo 2. In this study, HER2 and Topo 2 were analysed by MLPA and FISH. There was a high agreement between the two approaches, although MLPA was easier to perform and cheaper than FISH. In conclusion, MLPA is a fast and accurate quantitative method to detect HER2 and Topo 2 amplification, and could be considered a good alternative to FISH.

Fecal DNA for noninvasive diagnosis of colorectal cancer in immunochemical fecal occult blood test-positive individuals.

BACKGROUND: We aimed to define the potential of the fecal DNA assay as an alternative or in addition to the currently used immunochemical fecal occult blood test (iFOBT) for the early diagnosis of colorectal cancer. METHODS: A total of 560 individuals aged 50 to 69 years with a positive iFOBT were recruited from an Italian FOBT regional screening program. Twenty-six were diagnosed with adenocarcinoma, 264 with high-risk adenoma, and 54 with low-risk adenoma, whereas 216 subjects did not have premalignant or malignant lesions. Fecal DNA integrity was analyzed blindly by the fluorescence long DNA (FL-DNA) test. RESULTS: iFOBT and FL-DNA were largely independent variables (rs = 0.036, P = 0.42), with values ranging from 101 to 5,826 ng/mL and from 0 to 515 ng, respectively. Median values of both variables were significantly higher in cancer patients than in patients with noncancerous lesions or in healthy individuals. Moreover, iFOBT and FL-DNA values were individually associated with a number of pathologic parameters. Sequential use of the diagnostic iFOBT and FL-DNA methods showed that fecal DNA provided more accurate diagnostic information and was able to identify subgroups at different risk of cancer in iFOBT-positive individuals. CONCLUSIONS: A combined approach based on FL-DNA and iFOBT evaluation could help to better identify colorectal cancers and to determine a patient's risk of harboring a preneoplastic or neoplastic lesion. Further evaluation in a screening setting is needed to confirm this hypothesis. IMPACT: Fecal DNA could be a useful tool to better predict cancer risk in FOBT-positive individuals.

Quantitative fluorescence determination of long-fragment DNA in stool as a marker for the early detection of colorectal cancer.

BACKGROUND: A variety of molecular markers have been evaluated for the development of a non-invasive approach to the diagnosis of colorectal cancer. We aimed to validate the diagnostic accuracy, using the same threshold as in the previous pilot study, of fluorescent long DNA test as a relatively simple and inexpensive tool for colorectal cancer detection. METHODS: A case-control study was conducted on 100 healthy subjects and 100 patients at first diagnosis of colorectal cancer. Human long-fragment DNA in stool was quantified by fluorescence primers and a standard curve and expressed in DNA nanograms. RESULTS: We validated the 25-ng value, which emerged as the most accurate cut-off in the pilot study, obtaining 79% (95% CI, 71-87%) sensitivity and 89% (95% CI, 83-95%) specificity. Specificity was very high for all cut-off values (15-40 ng) analyzed, ranging from 78 to 96%. Sensitivity was only slightly lower, reaching 84% at the lowest cut-off and maintaining a good level at the higher values. Diagnostic potential was independent of gender, age and tumor site. CONCLUSION: Fecal DNA analysis is a non-invasive and fairly simple test showing high diagnostic potential. These characteristics, together with the small amount of stool required, make it potentially suitable to be used alongside or as an alternative to current non-invasive screening approaches. Our next step will be to validate these results in a large-scale cohort study of a screening population, which is needed prior to implementation into clinical practice.

KRAS, p53 and BRAF gene mutations and aneuploidy in sporadic colorectal cancer progression.

BACKGROUND: The origin and mechanisms of chromosomal instability are still widely unknown. We previously investigated a limited number of human sporadic colorectal cancers (CRCs) and observed a statistically different occurrence of KRAS and p53 mutations among predetermined subgroups of tumors with different degrees of DNA aneuploidy. The aim of the present study was to further verify these observations by including BRAF gene analysis and by investigating a larger series of cases subdivided into Dukes' stages A to D to reconstruct some form of chronological modulation for events during CRC progression. METHODS: KRAS, p53, BRAF mutations and flow cytometric DNA Index were evaluated by established techniques in a series of 135 human sporadic CRCs. RESULTS: p53, KRAS and BRAF mutations were found in 39%, 34%, and 4% of tumors, respectively. The frequency of p53 mutations increased from 15% for stage A to 48% for stage D and was highest in near-diploid (DI < 1.4 and DI does not equal 1) and high-aneuploid (DI > 1.6) tumors. A similar correlation between gene mutations and DI values was observed for KRAS. The simultaneous presence of KRAS and p53 mutations was observed in only 11% of cases. Moreover, the co-occurrence of p53 and KRAS mutations was only observed in near-diploid and high-aneuploid tumors. CONCLUSION: Our findings suggest that KRAS and p53 gene mutations, which are rarely simultaneous and are associated with specific DI aneuploid values, do not represent a synergistic evolutionary pathway but may influence mechanisms of chromosomal instability.

Mutation analysis of p53, K-ras, and BRAF genes in colorectal cancer progression.

Gene mutations in APC, K-ras, and p53 are thought to be essential events for colorectal cancer development. Recent data seem to indicate that K-ras and p53 mutations rarely co-exist in the same tumor, indicating that these alterations do not represent a synergistic evolutionary pathway. Moreover, an inverse relation between K-ras gene activation and BRAF mutations has been demonstrated, suggesting alternative pathways for colorectal cancer transformation. To reconstruct the chronological modulation of these gene mutations during cell transformation and colorectal cancer progression, mutations of p53, K-ras, and BRAF genes were analyzed by Single Strand Conformation Polymorphism (SSCP) or sequencing analysis in 100 colorectal cancer samples, evenly distributed among different Dukes' stages. We found mutations in p53, K-ras, and BRAF genes in 35%, 30%, and 4% of tumors, respectively, and observed a minimal or no co-presence of these gene alterations. Moreover, the frequency of molecular p53 mutations increased as tumor stage increased, suggesting an important role for this gene in the progression of colorectal cancer. Conversely, K-ras or BRAF genes were not related to tumor stage or location. These data seem to indicate the absence of a co-presence of the genes, highlighting the possibility of multiple pathways for colorectal tumor progression. Moreover, mutations in p53, K-ras, and BRAF are not present in about one-third of colorectal cancers and therefore other gene mutations need to be investigated to better understand molecular mechanisms at the basis of cell transformation and the progression of colorectal cancer.

Detection of colorectal cancer by a quantitative fluorescence determination of DNA amplification in stool.

DNA amplification of exfoliated cells in stool represents an inexpensive and rapid test, but has only 50% to 60% sensitivity. A new quantitative method, called fluorescence long DNA, was developed and validated in our laboratory on stool obtained from 86 patients with primary colorectal cancer and from 62 healthy individuals. It consists of the amplification of stool DNA with fluorescence primers and the quantification of the amplification using a standard curve. Results are arbitrarily expressed in nanograms. The potential of the new method compared to the conventional approach was analyzed in a subgroup of 94 individuals (56 patients and 38 healthy volunteers). In the present series, DNA amplification analysis showed a specificity of 97% and a sensitivity of only 50%. Conversely, fluorescence DNA evaluation, using the best cutoff of 25 ng, showed a sensitivity of about 76% and a specificity of 93%. Similar sensitivity was observed regardless of Dukes stage, tumor location, and size, thus also permitting the detection of early-stage tumors. The present study seems to indicate that quantitative fluorescence DNA determination in stool successfully identifies colorectal cancer patients with a sensitivity comparable, if not superior, to that of multiple gene analysis but at a lower cost and in a shorter time.

Fecal multiple molecular tests to detect colorectal cancer in stool.

BACKGROUND & AIMS: Evaluation of molecular alterations in fecal DNA is a potential, noninvasive, alternative tool for the detection of colorectal cancer. We analyzed a large panel of molecular alterations involved in tumor transformation and progression to define their single diagnostic contribution in terms of sensitivity, cost, and time required to carry out the different tests. METHODS: DNA was analyzed in stool from 38 healthy individuals and in paired stools and primary lesions from 56 patients with colorectal cancer. p53 exons 5-8, K-ras exons 1-2, four fragments of adenomatous polyposis coli (APC) exon 15, and 5 microsatellite loci were analyzed. Moreover, DNA amplification was evaluated for 4 exons of both p53 and APC. RESULTS: K-ras (34%) and p53 (34%) mutations were the most frequent alterations in tumors, followed by microsatellite instability (13%) and APC mutations (13%). The most frequent event in stool was DNA amplification (51%), followed by alterations of K-ras (11%), p53 and microsatellite instability (6%), and APC (2%). K-ras and p53 gene mutations increased the capacity of DNA amplification to detect tumor cells by 8%. CONCLUSIONS: K-ras and p53 gene mutations were the most frequent alterations observed in stool from patients with colorectal cancer, but DNA amplification was even more frequent, being present in more than half of patients. If these preliminary results are confirmed in a prospective study on a larger case series, this approach could be used for noninvasive colon cancer diagnosis in screening programs.