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58 result(s) for "Mavroudis, Dimitris"
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PIK3CA hotspot mutations in circulating tumor cells and paired circulating tumor DNA in breast cancer: a direct comparison study
Liquid biopsy analysis, mainly based on circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), provides an extremely powerful tool for the molecular profiling of cancer patients in real time. In this study, we directly compared PIK3CA hotspot mutations (E545K, H1047R) in EpCAM‐positive CTCs and paired plasma‐ctDNA in breast cancer (BrCa). PIK3CA hotspot mutations in CTCs and ctDNA were analyzed using our previously developed highly sensitive (0.05%), specific, and validated assay in plasma‐ctDNA from 77 early and 73 metastatic BrCa patients and 40 healthy donors. We further analyzed and directly compared PIK3CA hotspot mutations in DNAs isolated from CellSearch® cartridges (CTCs) and paired plasma‐ctDNA, in 56 cases of early and 27 cases of metastatic breast cancer, and 16 corresponding primary tumors. In plasma‐ctDNA, PIK3CA hotspot mutations were identified in 30/77(39.0%) early and 35/73(47.9%) metastatic BrCa cases; none (0/40, 0%) of the healthy donors’ plasma‐ctDNA samples were positive. Our direct comparison study in DNAs isolated from CellSearch® cartridges (CTCs) and paired plasma‐ctDNA from the same blood draws has shown a lack of concordance in early BrCa (27/56, 48.2%), while the concordance in the metastatic setting was higher (18/27, 66.6%). Our results were validated by ddPCR methodology, and the concordance between our assay and ddPCR for PIK3CA E545K hotspot mutation was 30/37 (81.1%). In many cases, PIK3CA hotspot mutations were detected in samples found to be negative for CTCs in CellSearch®. Our data demonstrated for the first time that (a) PIK3CA hotspot mutations are present at high frequencies in CTCs isolated from CellSearch® cartridges and paired plasma‐ctDNA both in early and metastatic BrCa, (b) the detection and concordance of PIK3CA hotspot mutations between plasma‐ctDNA and CTCs are higher in the metastatic setting, (c) PIK3CA mutational status significantly changes after therapeutic intervention, and (d) PIK3CA mutation detection in CTCs and plasma‐ctDNA provides complementary information. Our direct comparison study on the presence of PIK3CA hotspot mutations (E545K, H1047R) in EpCAM‐positive CTCs and paired plasma‐ctDNA demonstrated for the first time that PIK3CA mutations are present at high frequencies in both CTCs and paired plasma‐ctDNA and that there is a high concordance in the metastatic setting. PIK3CA mutational status significantly changes after therapeutic intervention.
Disease-free survival as a surrogate for overall survival in patients with HER2-positive, early breast cancer in trials of adjuvant trastuzumab for up to 1 year: a systematic review and meta-analysis
Although frequently used as a primary endpoint, disease-free survival has not been validated as a surrogate for overall survival in early breast cancer. We investigated this surrogacy in the adjuvant setting of treatment with anti-HER2 antibodies. In a systematic review and meta-analysis, we identified published and non-published randomised controlled trials with completed accrual and available disease-free survival and overall survival results for the intention-to-treat population as of September 2016. Bibliographic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials), clinical trial registries (Clinicaltrials.gov, EU Clinical Trials Register, WHO International Clinical Trials Registry Platform, and PharmNet.Bund), and trial registries from relevant pharmaceutical companies were searched. Eligibility for treatment of HER2-positive early breast cancer required at least one group to have an anti-HER antibody treatment (ie, trastuzumab, pertuzumab, or trastuzumab emtansine) planned for 12 months, and at least one control arm with chemotherapy without the antibody, a lower total dose or duration of the antibody, or observation alone. Units of analysis were contrasts: two-group trials gave rise to one contrast, whereas trials with more than two groups gave rise to more than one contrast. We excluded trials enrolling patients with recurrent, metastatic, or non-invasive disease, and those testing neoadjuvant therapy exclusively. Our primary objective was to estimate patient-level and trial-level correlations between disease-free survival and overall survival. We measured the association between disease-free survival and overall survival using Spearman's correlation coefficient (rs), and the association between hazard ratios (HRs) for disease-free survival and overall survival using R2. We computed the surrogate threshold effect, the maximum HR for disease-free survival that statistically predicts an HR for overall survival less than 1·00 in a future trial. Eight trials (n=21 480 patients) gave rise to a full set (12 contrasts). Patient-level associations between disease-free and overall survival were strong (rs=0·90 [95% CI 0·89–0·90]). Trial-level associations gave rise to values of R2 of 0·75 (95% CI 0·50–1·00) for the full set. Subgroups defined by nodal status and hormone receptor status yielded qualitatively similar results. Depending on the expected number of deaths in a future trial, the surrogate threshold effects ranged from 0·56 to 0·81, based on the full set. These findings suggest that it is appropriate to continue to use disease-free survival as a surrogate for overall survival in trials in HER-2-positive, early breast cancer. The key limitation of this study is the dependence of its results on the trials included and on the existence of an outlying trial. Roche Pharma AG.
Effect of body tissue composition on the outcome of patients with metastatic non-small cell lung cancer treated with PD-1/PD-L1 inhibitors
Obesity and sarcopenia have been reported to affect outcomes in patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs). We analyzed prospective data from 52 patients with non-oncogene driven metastatic NSCLC treated with ICIs. Body tissue composition was calculated by measuring the fat and muscle densities at the level of 3 rd lumbar vertebra in each patient computed tomography scan before ICI initiation using sliceOmatic tomovision. We converted the densities to indices [Intramuscular Fat Index (IMFI), Visceral Fat Index (VFI), Subcutaneous Fat Index (SFI), Lumbar Skeletal Muscle Index (LSMI)] by dividing them by height in meters squared. Patients were dichotomized based on their baseline IMFI, VFI and SFI according to their gender-specific median value. The cut-offs that were set for LMSI values were 55 cm 2 /m 2 for males and 39 cm 2 /m 2 for females. SFI distribution was significantly higher (p = 0.040 ) in responders compared to non-responders. None of the other variables affected response rates. Low LSMI HR: 2.90 (95% CI: 1.261–6.667, p = 0.012 ) and low SFI: 2.20 (95% CI: 1.114–4.333, p = 0.023 ) values predicted for inferior OS. VFI and IMFI values did not affect survival. Subcutaneous adipose and skeletal muscle tissue composition significantly affected immunotherapy outcomes in our cohort.
Evaluation of the detection of Toll-like receptors (TLRs) in cancer development and progression in patients with colorectal cancer
Toll-like receptors (TLRs) play essential role in innate and acquired immunity, are expressed in various cell types, and are associated with altered susceptibility to many diseases, and cancers. The aim of this study was to investigate TLR2 (-196 to-174del), TLR4 (Asp299Gly and Thr399Ile) and TLR9 (T1237C and T1486C) gene polymorphisms at risk of colorectal cancer (CRC) development and progression. Peripheral blood was obtained from 397 patients with adjuvant (stage II/III, n = 202) and metastatic (n = 195) CRC. Moreover, blood samples from 50 healthy volunteers and 40 patients with adenomatous polyps were also included as control groups. DNA from patients and controls was analyzed using PCR and PCR-RFLP for genotyping functional polymorphism within TLR2, TLR4 and TLR9 genotypes. TLR2-196 to-174del/del genotype was detected in 76.6% of the patients and was significantly higher that the controls groups (p<0.001). TLR4 Asp299Gly, TLR4 Thr399Ile, TLR9 T1237C and T1486C homozygous genotypes were detected in 70.5%, 70.5%, 61.5% and 61.5% of the patients respectively, and were also significantly higher than that in the control groups (p<0.001). All polymorphisms detected were also significantly associated with the metastatic disease (p<0.001) leading to shorter overall survival (p<0.001); whereas, TLR4 Asp299Gly and Thr399Ile polymorphisms were significantly associated with KRAS mutations. The detection of higher frequencies of the TLR2, TLR4 and/or TLR9 polymorphisms in CRC patients compared with the control groups highlight the role of these polymorphism in CRC development and cancer progression.
Gene expression profile of circulating tumor cells in breast cancer by RT-qPCR
Background Circulating tumor cells (CTCs) have been associated with prognosis especially in breast cancer and have been proposed as a liquid biopsy for repeated follow up examinations. Molecular characterization of CTCs is difficult to address since they are very rare and the amount of available sample is very limited. Methods We quantified by RT-qPCR CK-19, MAGE-A3, HER-2, TWIST1, hTERT α+β+ , and mammaglobin gene transcripts in immunomagnetically positively selected CTCs from 92 breast cancer patients, and 28 healthy individuals. We also compared our results with the CellSearch system in 33 of these patients with early breast cancer. Results RT-qPCR is highly sensitive and specific and can detect the expression of each individual gene at the one cell level. None of the genes tested was detected in the group of healthy donors. In 66 operable breast cancer patients, CK-19 was detected in 42.4%, HER-2 in 13.6%, MAGE-A3 in 21.2%, hMAM in 13.6%, TWIST-1 in 42.4%, and hTERT α+β+ in 10.2%. In 26 patients with verified metastasis, CK-19 was detected in 53.8%, HER-2 in 19.2%, MAGE-A3 in 15.4%, hMAM in 30.8%, TWIST-1 in 38.5% and hTERT α + β + in 19.2%. Our preliminary data on the comparison between RT-qPCR and CellSearch in 33 early breast cancer patients showed that RT-qPCR gives more positive results in respect to CellSearch. Conclusions Molecular characterization of CTCs has revealed a remarkable heterogeneity of gene expression between breast cancer patients. In a small percentage of patients, CTCs were positive for all six genes tested, while in some patients only one of these genes was expressed. The clinical significance of these findings in early breast cancer remains to be elucidated when the clinical outcome for these patients is known.
KRAS Genotypic Changes of Circulating Tumor Cells during Treatment of Patients with Metastatic Colorectal Cancer
Circulating tumor cells (CTCs) could represent a non-invasive source of cancer cells used for longitudinal monitoring of the tumoral mutation status throughout the course of the disease. The aims of the present study were to investigate the detection of KRAS mutations in CTCs from patients with metastatic colorectal cancer (mCRC) and to compare their mutation status during treatment or disease progression with that of the corresponding primary tumors. Identification of the seven most common KRAS mutations on codons 12 and 13 was performed by Peptide Nucleic Acid (PNA)-based qPCR method. The sensitivity of the assay was determined after isolation of KRAS mutant cancer cells spiked into healthy donors' blood, using the CellSearch Epithelial Cell kit. Consistent detection of KRAS mutations was achieved in samples containing at least 10 tumor cells/7.5 ml of blood. The clinical utility of the assay was assessed in 48 blood samples drawn from 31 patients with mCRC. All patients had PIK3CA and BRAF wild type primary tumors and 14 KRAS mutant tumors. CTCs were detected in 65% of specimens obtained from 74% of patients. KRAS mutation analysis in CTC-enriched specimens showed that 45% and 16.7% of patients with mutant and wild type primary tumors, respectively, had detectable mutations in their CTCs. Assessing KRAS mutations in serial blood samples revealed that individual patient's CTCs exhibited different mutational status of KRAS during treatment. The current findings support the rationale for using the CTCs as a dynamic source of tumor cells which, by re-evaluating their KRAS mutation status, could predict, perhaps more accurately, the response of mCRC patients to targeted therapy.
A Circulating Subpopulation of Monocytic Myeloid-Derived Suppressor Cells as an Independent Prognostic/Predictive Factor in Untreated Non-Small Lung Cancer Patients
Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of cells with immunosuppressive properties and might confer to worse prognosis in cancer patients. The presence of phenotypically newly described subpopulations of MDSCs and their association with the clinical outcome were investigated in non-small cell lung cancer (NSCLC) patients. The percentages and correlation between MDSCs and distinct immune cells in the peripheral blood of 110 chemotherapy-naive patients before treatment and healthy controls were investigated using flow cytometry. Two monocytic [CD14+CD15−CD11b+CD33+HLA-DR−Lin− and CD14+CD15+CD11b+CD33+HLA-DR−Lin−] and a granulocytic [CD14−CD15+CD11b+CD33+HLA-DR−Lin−] subpopulations of MDSCs were identified, expressing inducible nitric oxide synthase, and reactive oxygen species, respectively. Increased percentages of both monocytic-MDSCs’ subpopulations were inversely correlated to dendritic/monocyte levels ( P ≤ 0.04 ) , while granulocytic-MDSCs were inversely correlated to CD4+ T cells ( P = 0.006 ) . Increased percentages of monocytic-MDSCs were associated with worse response to treatment ( P = 0.02 ) and patients with normal levels of CD14+CD15+CD11b+CD33+HLA-DR−Lin− had longer overall survival and progression free-survival compared to those with high levels ( P = 0.008 and P = 0.005 , resp.). Multivariate analysis revealed that the increased percentages of CD14+CD15+CD11b+CD33+HLA-DR−Lin− MDSCs were independently associated with decreased progression free-survival and overall survival. The data provide evidence that increased percentages of new monocytic-MDSCs’ subpopulations in advanced NSCLC patients are associated with an unfavourable clinical outcome.
Impact of KRAS, BRAF, PIK3CA mutations, PTEN, AREG, EREG expression and skin rash in ≥ 2 line cetuximab-based therapy of colorectal cancer patients
To investigate the predictive significance of KRAS, BRAF, PIK3CA mutational status, AREG- EREG mRNA expression, PTEN protein expression and skin rash in metastatic colorectal cancer (mCRC) patients treated with cetuximab containing salvage chemotherapy. Primary tumors from 112 mCRC patients were analyzed. The worst skin toxicity during treatment was recorded. KRAS, BRAF and PIK3CA mutations were present in 37 (33%), 8 (7.2%) and 11 (9.8%) cases, respectively, PTEN was lost in 21 (19.8%) cases, AREG and EREG were overexpressed in 48 (45%) and 51 (49%) cases. In the whole study population, time to tumor progression (TTP) and overall survival (OS) was significantly lower in patients with KRAS (p = 0.001 and p = 0.026, respectively) or BRAF (p = 0.001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.018 and p = 0.013, respectively) or EREG (p = 0.002 and p = 0.004, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). In KRAS wt patients TTP and OS was significantly lower in patients with BRAF (p = 0.0001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.021 and p = 0.004, respectively) or EREG (p = 0.0001 and p<0.0001, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). TTP was significantly lower in patients with PIK3CA mutations (p = 0.01) or lost PTEN (p = 0.002). Multivariate analysis revealed KRAS (Hazard Ratio [HR] 4.3, p<0.0001), BRAF mutation (HR: 5.1, p<0.0001), EREG low expression (HR: 1.6, p = 0.021) and absence of severe/moderate skin rash (HR: 4.0, p<0.0001) as independent prognostic factors for decreased TTP. Similarly, KRAS (HR 2.9, p = 0.01), BRAF mutation (HR: 3.0, p = 0.001), EREG low expression (HR: 1.7, p = 0.021), absence of severe/moderate skin rash (HR: 3.7, p<0.0001) and the presence of undifferantited tumours (HR: 2.2, p = 0.001) were revealed as independent prognostic factors for decreased OS. These results underscore that KRAS-BRAF mutations and EREG expression can be used as biomarkers to further select patients undergoing anti-EGFR treatment.
BRAFV600E Mutation Analysis in Patients with Metastatic Colorectal Cancer (mCRC) in Daily Clinical Practice: Correlations with Clinical Characteristics, and Its Impact on Patients’ Outcome
To prospectively evaluate the usefulness of the BRAFV600E mutation detection in daily clinical practice in patients with metastatic Colorectal Cancer (mCRC). 504 mCRC patients treated with systemic chemotherapy ± biologics were analyzed. A statistically significant higher incidence of the BRAF mutation was observed in patients with ECOG-PS 2 (p=0.001), multiple metastatic sites (p=0.002),> 65 years old (p=0.004), primary tumors located in the colon (p<0.001), high-grade tumors (p=0.001) and in those with mucinous features (p=0.037). Patients with BRAFV600E mutated tumors had a statistically significantly reduced progression-free survival (PFS) compared to wild-type (wt) ones (4.1 and 11.6 months, respectively; p<0.001) and overall survival (OS) (14.0 vs. 34.6 months, respectively; p<0.001). In the multivariate analysis the BRAFV600E mutation emerged as an independent factor associated with reduced PFS (HR: 4.1, 95% CI 2.7-6.2; p<0.001) and OS (HR: 5.9, 95% CI 3.7-9.5; p<0.001). Among the 273 patients treated with salvage cetuximab or panitumumab, the BRAFV600E mutation was correlated with reduced PFS (2.2 vs. 6.0 months; p<0.0001) and OS (4.3 vs. 17.4 months; p<0.0001). The presence of BRAFV600E-mutation in mCRC characterizes a subgroup of patients with distinct biologic, clinical and pathological features and is associated with very poor patients' prognosis.
Combined analysis of KRAS and PIK3CA mutations, MET and PTEN expression in primary tumors and corresponding metastases in colorectal cancer
Metastasis is the main cause of mortality in patients with colorectal cancer. However, most of the targeted therapies and predictive molecular biomarkers were developed based mainly on primary tumors. The current study was conducted to determine the degree of discordance between potential predictive and/or prognostic molecular markers in primary colorectal tumors and corresponding metastases, as this could have an impact on the efficacy of targeted therapies in the advanced colorectal cancer. KRAS , PIK3CA and BRAF mutations were determined by Sanger sequencing and mutant-enriched polymerase chain reaction (PCR) assays in 83 paired samples, MET gene copy number by quantitative PCR in 59, MET expression by immunohistochemistry in 73 and nuclear and cytoplasmic expression of PTEN by immunohistochemistry in 78 and 71 pairs, respectively. A certain degree of discordance between primary tumors and corresponding metastases was demonstrated for all examined biomarkers except BRAF mutations. PIK3CA exon 9 mutations in primary tumors and loss of PTEN nuclear expression in metastases correlated with KRAS mutations. KRAS wild-type status in primary tumors was associated with loss of PTEN cytoplasmic expression and high gene copy number of MET . Survival and clinical data were available for 68 patients. The multiple regression analysis revealed that the right-sided tumor localization and overexpression of MET were associated with shorter overall survival.