Neurotoxic effects of low dose ranges of environmental metal mixture in a rat model: The benchmark approach.

Metals exert detrimental effects on various systems within the body, including the nervous system. Nevertheless, the dose-response relationship concerning the administration of low doses of metal mixtures remains inadequately explored. The assessment of neurotoxic effects of lead, cadmium, mercury, and arsenic mixture (MIX) administered at low dose ranges, was conducted using an in vivo approach. A subacute study was conducted on a rat model consisting of a control and five treatment groups subjected to oral exposure with gradually increasing doses (from MIX 1 to MIX 5). The results indicated that behavioural patterns in an already developed nervous system displayed a reduced susceptibility to the metal mixture exposure with tendency of higher doses to alter short term memory. However, the vulnerability of the mature brain to even minimal amounts of the investigated metal mixture was evident, particularly in the context of oxidative stress. Moreover, the study highlights superoxide dismutase's sensitivity as an early-stage neurotoxicity marker, as indicated by dose-dependent induction of oxidative stress in the brain revealed through Benchmark analysis. The narrowest Benchmark Dose Interval (BMDI) for superoxide dismutase (SOD) activity (1e-06 - 3.18e-05 mg As/kg b.w./day) indicates that arsenic may dictate the alterations in SOD activity when co-exposed with the other examined metals. The predicted Benchmark doses for oxidative stress parameters were very low, supporting "no-threshold" concept. Histopathological alterations were most severe in the groups treated with higher doses of metal mixture. Similarly, the brain acetylcholinesterase (AChE) activity demonstrated a dose-dependent decrease significant in higher doses, while BMDI suggested Cd as the main contributor in the examined metal mixture. These findings imply varying susceptibility of neurotoxic endpoints to different doses of environmentally relevant metal mixtures, advocating for risk assessment and regulatory measures to address metal pollution and enhance remediation strategies.

Data-Independent Acquisition Mass Spectrometry Analysis of FFPE Rectal Cancer Samples Offers In-Depth Proteomics Characterization of the Response to Neoadjuvant Chemoradiotherapy.

Locally advanced rectal cancer (LARC) presents a challenge in identifying molecular markers linked to the response to neoadjuvant chemoradiotherapy (nCRT). This study aimed to utilize a sensitive proteomic method, data-independent mass spectrometry (DIA-MS), to extensively analyze the LARC proteome, seeking individuals with favorable initial responses suitable for a watch-and-wait approach. This research addresses the unmet need to understand the response to treatment, potentially guiding personalized strategies for LARC patients. Post-treatment assessment included MRI scans and proctoscopy. This research involved 97 LARC patients treated with intense chemoradiotherapy, comprising radiation and chemotherapy. Out of 97 LARC included in this study, we selected 20 samples with the most different responses to nCRT for proteome profiling (responders vs. non-responders). This proteomic approach shows extensive proteome coverage in LARC samples. The analysis identified a significant number of proteins compared to a prior study. A total of 915 proteins exhibited differential expression between the two groups, with certain signaling pathways associated with response mechanisms, while top candidates had good predictive potential. Proteins encoded by genes SMPDL3A, PCTP, LGMN, SYNJ2, NHLRC3, GLB1, and RAB43 showed high predictive potential of unfavorable treatment outcome, while RPA2, SARNP, PCBP2, SF3B2, HNRNPF, RBBP4, MAGOHB, DUT, ERG28, and BUB3 were good predictive biomarkers of favorable treatment outcome. The identified proteins and related biological processes provide promising insights that could enhance the management and care of LARC patients.

Prognostic relevance of autophagy-related markers p62, LC3, and Beclin1 in ovarian cancer.

AIM: To analyze the expression of autophagy markers p62, LC3, and Beclin1 in ovarian cancer tissue and evaluate the prognostic potential of these markers. METHODS: The study enrolled 328 patients: 122 with epithelial ovarian carcinoma, 42 with atypical proliferative tumor, and 164 with benign epithelial ovarian tumor. The expression of p62, LC3, and Beclin1 was analyzed in central and invasive tumor segments with immunohistochemistry combined with tissue microarray. The expression levels of the analyzed markers were correlated with relevant histopathology parameters. RESULTS: The expression of all analyzed markers was most remarkable in epithelial ovarian carcinoma. There was a strong positive correlation between the expressions of p62 and LC3, while these two markers negatively correlated with Beclin1. High-grade serous carcinoma had higher p62 and LC3 levels, and lower Beclin1 levels than other tumor types. This expression profile was also observed in more advanced tumor stages. CONCLUSION: Prominent p62 and LC3 expression in combination with weak Beclin1 expression in high-grade serous carcinoma indicates potential for the application of autophagy inhibitors in patients with this tumor subtype.

PD-L1 Expression in Different Segments and Histological Types of Ovarian Cancer According to Lymphocytic Infiltrate.

Background and Objectives: Ovarian cancer is the leading cause of death among gynecological tumors. PD-1/PD-L1 immunoregulatory mechanism is activated in ovarian cancers. Lymphocyte infiltration is a significant factor that affects its expression. We analyzed the correlation between localization of lymphocytic infiltrate and PD-L1 expression in epithelial ovarian tumors. Materials and Methods: PD-L1 expression was analyzed in 328 subjects, 122 with epithelial ovarian carcinoma, 42 with atypical proliferative tumor, and 164 with benign epithelial ovarian tumor. Expression in central and invasive tumor parts in epithelial ovarian carcinoma was combined with the most pronounced lymphocyte reaction. Immunohistochemical analysis was performed using the tissue microarray and correlated with a set of histopathology parameters. Results: PD-L1 expression was most prominent in epithelial ovarian carcinoma with different levels of expression observed between invasive and central tumor segments. A high level of PD-L1 expression on tumor cells was more frequently present in the invasive than in the central tumor parts (p < 0.001) only in high-grade serous ovarian carcinoma (HGSC). There was no significant correlation between peritumoral lymphocytic infiltrate and PD-L1 expression regardless of tumor segment. In the central tumor parts of HGSC, there was a correlation of intratumoral lymphocytic infiltrate with a higher level of PD-L1 expression (p = 0.003). Conclusions: The most prominent PD-L1 expression was observed in the invasive tumor parts of HGSC. Only the central parts of the HGSC exhibited significant PD-L1 expression in association with considerable intratumoral lymphocytic infiltrate.

Mahonia aquifolium Extracts Promote Doxorubicin Effects against Lung Adenocarcinoma Cells In Vitro.

Mahonia aquifolium and its secondary metabolites have been shown to have anticancer potential. We performed MTT, scratch, and colony formation assays; analyzed cell cycle phase distribution and doxorubicin uptake and retention with flow cytometry; and detected alterations in the expression of genes involved in the formation of cell-cell interactions and migration using quantitative real-time PCR following treatment of lung adenocarcinoma cells with doxorubicin, M. aquifolium extracts, or their combination. MTT assay results suggested strong synergistic effects of the combined treatments, and their application led to an increase in cell numbers in the subG1 phase of the cell cycle. Both extracts were shown to prolong doxorubicin retention time in cancer cells, while the application of doxorubicin/extract combination led to a decrease in MMP9 expression. Furthermore, cells treated with doxorubicin/extract combinations were shown to have lower migratory and colony formation potentials than untreated cells or cells treated with doxorubicin alone. The obtained results suggest that nontoxic M. aquifolium extracts can enhance the activity of doxorubicin, thus potentially allowing the application of lower doxorubicin doses in vivo, which may decrease its toxic effects in normal tissues.

Diagnosis of Eosinophilic Esophagitis in Children: A Serbian Single-Center Experience from 2010 to 2017.

OBJECTIVES: The aim of this study was to assess the epidemiological, clinical, endoscopic, and pathohistological characteristics of pediatric eosinophilic esophagitis (EoE) in Serbia. METHOD: All children aged 0-18 years diagnosed with EoE in the period between 2010 and 2017 at the University Children's Hospital in Belgrade, Serbia, were retrospectively enrolled. RESULTS: EoE was diagnosed in 35 children (12.45 ± 3.77 years) with a male predominance (74%). The median incidence rate was estimated to be 0.85 per 100,000 children per year with the highest rate estimated at 3.17 per 100,000 children in 2017. Dysphagia (71.4%) and food impaction (40%) were dominant symptoms. Inflammatory endoscopic changes were found in 74.3% and fibrostenotic changes in 62.9% of the children. The esophageal biopsy rate was low (6.8%), especially in children with reflux and nonspecific symptoms. Subepithelial fibrosis was found in only 20% of the patients. Since 2016, the number of biopsy samples has increased, but the sampling rate of lamina propria is still low (<50%). The correlation between the number of biopsies and lamina propria acquisition was strong (rs = 0.773, p < 0.05). In 2 immunocompetent adolescents, EoE was diagnosed after successful treatment of infectious esophagitis. CONCLUSIONS: An increase in the incidence of EoE in Serbian children is evident. The biopsy rate in children with nonspecific and reflux symptoms should be increased, as well as the number of biopsy samples for the detection of subepithelial fibrosis. In immunocompetent children with infectious esophagitis, EoE should be suspected and endoscopy may be recommended after successful treatment of infection.

Evaluation of the Functional Capacity of NK Cells of Melanoma Patients in an In Vitro Model of NK Cell Contact with K562 and FemX Tumor Cell Lines.

NK cells of metastatic melanoma (MM) patients display impaired function, making them incapable to mount an effective antitumor response. In this study, we evaluated immunophenotypic characteristics and functional capacity of CD3-CD16+ NK cells of MM patients in an in vitro model based on NK cell contact with an NK sensitive, K562, and a tumor-specific, melanoma FemX tumor cell line. Although our results indicate similar NK cell antitumor cytotoxic potential of MM patients in contact with both cell lines based on the expression of CD107a degranulation marker, there is a discrepancy in NK cell IFNγ production, as it is not significantly induced by FemX tumor cells, found to be, contrary to K562, HLA class I positive. Furthermore, we show NKG2D receptor downregulation by K562 tumor cell line, only. This may result from the obtained higher gene expression of TGFß and VEGFA growth factors in K562 tumor cells that can negatively regulate NKG2D expression. Additionally, aside from postcontact downmodulation of activating CD16 receptor, there are no significant changes in the expression of CD161, CD158a, and CD158b NK cell receptors. Therefore, the applied in vitro model shows that, compared to the full NK cell functional capacity of MM patients displayed in a tumor-sensitive setting represented by contact with K562 cells, tumor-specific melanoma setting provided by FemX tumor cells leads to reduced NK functional potential. The obtained insight into NK cell capacity may be of use for evaluation of the state of disease and can help in selecting effective immunotherapeutic agents for MM patients.

Clarification of serotonin-induced effects in peripheral artery disease observed through the femoral artery response in models of diabetes and vascular occlusion: The role of calcium ions.

Recent findings have demonstrated that serotonin is an important participant in the development and progression of peripheral artery diseases. Taking this into consideration, the goals of this study were to investigate the effects of serotonin on isolated Wistar rat femoral arteries in both healthy and diabetic animals, with and without artery occlusion, with a particular focus on determining the role of calcium in this process. Contraction experiments with serotonin on intact and denuded femoral artery rings, in the presence or absence of nifedipine and ouabain (both separately, or in combination), as well as Ca2+ -free Krebs-Ringer bicarbonate solution were performed. The serotonin-induced results were concentration dependent, but only in healthy animals. The endothelium-dependent contraction of the femoral artery was assessed. In healthy animals, the endothelium-reliant part of contraction was dependent on the extracellular calcium, while the smooth muscle-related part was instead dependent on the intracellular calcium. In diabetic animals, both nifedipine and ouabain influenced serotonin-induced vascular effects by blocking intracellular calcium pathways. However, this was diminished after the simultaneous administration of both blockers.

Tumor response and patient outcome after preoperative radiotherapy in locally advanced non-inflammatory breast cancer patients.

PURPOSE: The purpose of this analysis was to assess the tumor response and long-term outcome in patients treated with preoperative radiotherapy (PRT) without systemic therapy. METHODS: Between 1997 and 2000, 134 patients with non-inflammatory locally advanced breast cancer (LABC) were treated with PRT. The tumor dose was 45 Gy in 15 fractions to the breast and to regional lymph nodes over 6 weeks. Radical mastectomy was performed 6 weeks after PRT to all patients and adjuvant systemic therapy was administered as per protocol. The measures of disease outcome were overall survival (OS) and disease-free survival (DFS) which estimated using the Kaplan-Meier method. RESULTS: Median follow-up was 74 months (range 4-216). Objective clinical tumor response after PRT was observed in 77.6% of the patients. Clinical complete tumor response (cCR) was achieved in 21.6% of the patients. Pathological CR in the breast was achieved in 15% of the patients. The 5- and 10-year OS were 55.1 and 37.8%, respectively. The 5- and 10-year DFS were 39.2 and 27%, respectively. Patients who achieved cCR had significantly longer OS in comparison with patients achieving clinical partial response (cPR) and clinical stable disease (cSD). Similarly, DFS of patients in the cCR group was longer compared with patients with cPR and cSD, yet without statistical significance. CONCLUSIONS: Our results showed that local control in LABC patients achieved by primary PRT, followed by radical mastectomy was comparable with the results reported in the literature. Complete pathologic response to PRT identified a subgroup of patients with a trend toward better DFS and OS.

p21 does, but p53 does not predict pathological response to preoperative chemoradiotherapy in locally advanced rectal cancer.

PURPOSE: Preoperative chemoradiotherapy (CRT) is the standard treatment option in locally advanced rectal cancer. The tumor response is assessed through tumor and nodal downstaging and the tumor regression grade. Currently, there is no method to predict a tumor response to CRT. We aimed to evaluate whether p21 and p53 expressions could be a reliable predictors of pathological response to CRT. METHODS: Fifty patients with locally advanced rectal cancer were treated with preoperative radiotherapy combined with mitomycin C and capecitabine. p21 and p53 immumohistochemical staining was performed on pretreatment biopsies and the results were compared with tumor regression according to grading systems by Dworak (TRG grades) and by Wheeler (RCRG grades). RESULTS: Testing RCRG grades in relation to p21 expression showed statistically significant difference (p=0.021). RCRG 3 (poor response) was more frequent in the group of patients with low p21. According to Dworak, grade 4 (complete regression) was more frequent in the group of patients with positive p21 expression (p=0.032). Significant difference in p21 expression in grade 4 group compared with all other grade groups was also found (p=0.007). Patients with immune expression of p21 had significantly higher percentage of complete regression in comparison to the patients with low expression of p21. We haven't found any correlation between p53 expression and histopathological (HP) as well as regression grades. CONCLUSION: According to both grading systems, our results suggest that p53 expression does not, but p21 expression does predict pathological response to preoperative CRT.

Pharmacogenetics in cancer therapy - 8 years of experience at the Institute for Oncology and Radiology of Serbia.

PURPOSE: Pharmacogenetics is a study of possible mechanism by which an individual's response to drugs is genetically determined by variations in their DNA sequence. The aim of pharmacogenetics is to identify the optimal drug and dose for each individual based on their genetic constitution, i.e. to individualize drug treatment. This leads to achieving the maximal therapeutic response for each patient, while reducing adverse side effects of therapy and the cost of treatment. A centralized pharmacogenetics service was formed at the Institute for Oncology and Radiology of Serbia (IORS) with the aim to provide a personalized approach to cancer treatment of Serbian patients. METHODS: Analyses of KRAS mutations in metastatic colorectal cancer, EGFR mutations in advanced non-small cell lung cancer, CYP2D6 polymorphism in breast cancer, DPD polymorphism in colorectal cancer and MTHFR polymorphism in osteosarcoma have been performed by real time polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Mutation testing analyses were successful for 1694 KRAS samples and 1821 EGFR samples, while polymorphism testing was successful for 9 CYP2D6 samples, 65 DPD samples and 35 MTHFR samples. CONCLUSIONS: Pharmacogenetic methods presented in this paper provide cancer patients in Serbia the best possible choice of treatment at the moment.

Pnck overexpression in HER-2 gene-amplified breast cancer causes Trastuzumab resistance through a paradoxical PTEN-mediated process.

The gene for Pregnancy Up-regulated Non-ubiquitous Calmodulin Kinase (Pnck), a novel calmodulin kinase, is expressed in roughly one-third of human breast tumors, but not in adjoining normal tissues. Pnck alters EGFR stability and function, prompting this study to determine if Pnck expression has implications for HER-2 function and HER-2-directed therapy. The frequency of Pnck expression in HER-2-amplified breast cancer was examined by immunohistochemistry, and the impact of Pnck expression in the presence of HER-2 amplification on cancer cell proliferation, clonogenicity, cell-cycle progression, and Trastuzumab sensitivity was examined in vitro by transfection of cells with Pnck. Cell signaling was probed by Western blot analysis and shRNA-mediated PTEN knockdown. Over 30 % of HER-2 amplified tumors were found to express Pnck. Expression of Pnck in SkBr3 cells resulted in increased proliferation, clonal growth, cell-cycle progression, and Trastuzumab resistance. Pnck expression increases Hsp27 expression, Trastuzumab partial agonist activity on HER-2 Y1248 phosphorylation, and suppressed extracellular signal-regulated kinase (ERK1/2) activity. Knockdown of endogenous PTEN upregulated ERK1/2 activity, inhibited cellular proliferation, and partially sensitized Pnck/SKBr3 cells to Trastuzumab treatment. Increased proliferation of the Pnck/SKBr3 cells was observed following expression of protein phosphatase active and lipid phosphatase dead PTEN mutant but not the total phosphatase dead PTEN mutant. Co-overexpression of HER-2 and Pnck results in enhanced tumor cell proliferation and Trastuzumab resistance that is paradoxically dependent on PTEN protein phosphatase activity. This suggests that Pnck may be a marker of Trastuzumab resistance and possibly a therapeutic target.

Overall human papilloma virus and types 16/18 prevalence in women with normal cervical cytology in Serbia: is it time for human papillomavirus testing and/or vaccination?

PURPOSE: Infection with high-risk human papilloma viruses (HR-HPV), especially types 16/18, is the main factor in cervical carcinogenesis. Although the incidence of cervical cancer in Serbia is among the highest ones in Europe, data about HPV infection are insufficient. The aim of this study was to investigate the presence of overall and HPV16/18 infections in women with healthy appearance and cytologically (Pap) normal cervix. METHODS: The study was performed on women who participated in this cervical cancer screening pilot study. Cervical HPV infection was detected by GP5+/6+ PCR. HPV16/18 were detected by amplification of E7/E1 viral gene, respectively. RESULTS: In 350 women we got the following results: cytological abnormalities (10.3%); visible cervical changes (20.3%); previous precancerous lesion (2.3%); normal Pap and speculum finding without history of precancerous lesion (67.1%). In the last group overall HPV prevalence was 41.3%, with 10.5% HPV16 and 23.7% HPV18. The rate of multiple HPV16 plus HPV18 infections was 2.6%. HR-HPV16/18 comprised 31.6% of the total HPV positive participants. CONCLUSION: Owing to the high prevalence of overall and HPV16/18 infections in women with healthy appearance and cytologically normal cervix, we postulate that testing/ prophylaxis for these HR-HPV types could be introduced in cervical cancer screening and preventive programmes in Serbia.

The influence of methylenetetrahydrofolate reductase and thymidylate synthetase gene polymorphisms on lung adenocarcinoma occurrence.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthetase (TYMS) are suggested as risk factors for lung cancer. The purpose of this study was to analyze the association of MTHFR C677T polymorphism and variable number tandem repeat 2R/3R and single nucleotide polymorphism G>C in the 3R allele of the TYMS gene with lung adenocarcinoma. METHODS: A case-control study including lung adenocarcinoma patients and healthy subjects was performed. Restriction fragment length polymorphism analysis was used for genotyping. Descriptive analyses included genotype and allelic frequencies; the odds ratio and 95% confidence interval were calculated as an estimate of relative risk. Significance was set at p<0.05. RESULTS: A significant difference in CC vs TT+CT MTHFR genotype distribution was observed between patients and controls. There was no significant association between the TYMS polymorphisms and the risk of lung adenocarcinoma. CONCLUSIONS: The MTHFR 677T allele is likely to have a protective effect against lung adenocarcinoma development.

Pediatric Crohn's Disease in the Upper Gastrointestinal Tract: Clinical, Laboratory, Endoscopic, and Histopathological Analysis.

Crohn's disease (CD) is a progressive, multifactorial, immune-mediated disease characterized by chronic inflammation of any part of the gastrointestinal (GI) tract. Pediatric patients present with a more extensive form of the disease, especially in the upper GI tract with various histopathological inflammatory patterns. Our study aims to analyze the clinical, laboratory, endoscopic, and histopathological findings in children with diagnosed CD and compare results on the initial and follow-up tests. We have included 100 children and adolescents with CD, with performed endoscopic and histopathological (HP) procedures. The results of multiple biopsies executed in these 8 years were matched and compared. We found a statistically significant frequency reduction in stool changes (65.52% to 18.18%), weight loss (35.24% to 4%), and abdominal pain (41.86% to 6.67%) as presenting symptoms. There was an improvement in all laboratory values: fecal calprotectin (1000 to 60,8 µg/g), C-reactive protein (12.2 to 1.9 mg/L), and albumin (36 to 41 g/L). On esophagogastroduodenoscopy and ileo-colonoscopy 36.59% and 64.86% patients had specific findings, respectively. A total of 32 patients had evidence of Crohn's disease in the upper GI tract. Non-caseating granulomas were found on 9% of oesophageal, 18% of gastric, and 12% of duodenal biopsies. In the lower GI tract, we have observed a disease progression in the rectum (72.29 to 82.22%) and descending colon (73.49 to 80%). There was no registered disease progression in the upper GI tract. Our study demonstrated a significant decline in the frequency of symptoms and an improvement in laboratory values on the follow-up examinations. More than a third of our patients had specific endoscopic and HP findings in the upper GI tract, and an additional 23% had HP findings highly suggestive of CD. We demonstrated the importance of regular clinical, laboratory, endoscopic, and histopathological assessments of pediatric CD patients.

NMDA Receptor Antagonist Memantine Ameliorates Experimental Autoimmune Encephalomyelitis in Aged Rats.

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age of the MS population is increasing and the number of elderly MS patients is expected to increase. In addition to neurons, N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronal cells, such as immune cells. The aim of this study was to investigate the role of NMDARs in experimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and aged Dark Agouti rats from day 7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease, reactivation, and apoptosis of CD4+ T cells in the target organ of aged EAE rats. The expression of the fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent in aged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes' mRNA expression in brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advanced oxidation protein products in brain tissue were consistent with previous results. Overall, our results suggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

Markers of Epithelial-Mesenchymal Transition and Mucinous Histology Are Significant Predictors of Disease Severity and Tumor Characteristics in Early-Onset Colorectal Cancer.

Approximately 20% of patients with colorectal cancer (CRC) are diagnosed with a mucinous subtype of this tumor, have a worse prognosis, and often show resistance to available therapies. Molecules from the mucin family are involved in the regulation of epithelial-mesenchymal transition (EMT), which significantly determines the cancer aggressiveness. This study aimed to examine the diagnostic and prognostic significance of mucinous histology and EMT markers in patients with early-onset CRC and their association with disease severity and tumor characteristics. This study included tumor tissue samples from 106 patients diagnosed with CRC before the age of 45, 53 with mucinous and 53 with non-mucinous tumors. The EMT status was determined by immunohistochemical analysis of E-cadherin and Vimentin in tissue sections. Mucinous tumors had significantly higher Mucin-1 (p < 0.001) and cytoplasmic E-cadherin (p = 0.043) scores; they were significantly less differentiated (p = 0.007), more advanced (p = 0.027), and predominately affected right the colon (p = 0.039) compared to non-mucinous tumors. Epithelial tumors were significantly better differentiated (p = 0.034) and with less prominent tumor budding (p < 0.001) than mesenchymal tumors. Mucin-1 and Vimentin were independent predictors of tumor differentiation (p = 0.006) and budding (p = 0.001), respectively. Mucinous histology and EMT markers are significant predictors of disease severity and tumor characteristics in early-onset colorectal cancer.

Performance and Dimensionality of Pretreatment MRI Radiomics in Rectal Carcinoma Chemoradiotherapy Prediction.

(1) Background: This study aimed to develop a machine learning model based on radiomics of pretreatment magnetic resonance imaging (MRI) 3D T2W contrast sequence scans combined with clinical parameters (CP) to predict neoadjuvant chemoradiotherapy (nCRT) response in patients with locally advanced rectal carcinoma (LARC). The study also assessed the impact of radiomics dimensionality on predictive performance. (2) Methods: Seventy-five patients were prospectively enrolled with clinicopathologically confirmed LARC and nCRT before surgery. Tumor properties were assessed by calculating 2141 radiomics features. Least absolute shrinkage selection operator (LASSO) and multivariate regression were used for feature selection. (3) Results: Two predictive models were constructed, one starting from 72 CP and 107 radiomics features, and the other from 72 CP and 1862 radiomics features. The models revealed moderately advantageous impact of increased dimensionality, with their predictive respective AUCs of 0.86 and 0.90 in the entire cohort and 0.84 within validation folds. Both models outperformed the CP-only model (AUC = 0.80) which served as the benchmark for predictive performance without radiomics. (4) Conclusions: Predictive models developed in this study combining pretreatment MRI radiomics and clinicopathological features may potentially provide a routine clinical predictor of chemoradiotherapy responders, enabling clinicians to personalize treatment strategies for rectal carcinoma.

The usability of allele-specific PCR and reverse-hybridization assays for KRAS genotyping in Serbian colorectal cancer patients.

BACKGROUND: Colorectal cancers (CRCs) with wild-type KRAS respond to EGFR-targeted antibody treatment. Analysis of the hotspot clustered mutations in codons 12 and 13 is compulsory before therapy and no standardized methodology for that purpose has been established so far. Since these mutations may have different biological effects and clinical outcome, reliable frequency and types of KRAS mutations need to be determined for individual therapy. AIMS: The purpose of this study was to describe the KRAS mutation spectrum in a group of 481 Serbian mCRC patients and to compare the general performances of allele-specific PCR and reverse-hybridization assays. METHODS: KRAS testing was performed with two diagnostic analyses, DxS TheraScreen K-RAS PCR Kit and KRAS StripAssay™. RESULTS: KRAS mutations in codons 12 and 13 were present in 37.6 % of analyzed formalin-fixed paraffin-embedded (FFPE) DNA samples. The seven most frequent mutation types were observed with both assays: p.G12D 34.6 %, p.G12V 24.9 %, p.G12A 10.3 %, p.G12C 8.1 %, p.G12S 5.4 %, p.G12R 1.6 %, and p.G13D 15.1 %. Regarding double mutants, 0.8 % of them were present among all tested samples and 2.2 % among KRAS mutated ones. CONCLUSIONS: Two screening approaches that were used in this study have been shown as suitable tests for detecting KRAS mutations in diagnostic settings. In addition, they appear to be good alternatives to methods presently in use. In our experience, both methods showed capacity to detect and identify double mutations which may be important for potential further subgrouping of CRC patients.