Molecular Markers In Colorectal Cancer Research Articles

Implication of exon 4 TP53 Gene mutations in colorectal cancers in Senegalese patients

Background: Colorectal cancer (CRC) is a major cause of death in men and women, comprising about 10% of cancer deaths after breast and lung cancer. The most significant risk factors currently implicated in the etiology of this cancer are genetic, likely due to several mutations. Methods: The study explored the involvement of genetic factors in these pathologies; specifically, exon 4 of the TP53 gene was studied in 15 CRC patients and compared with 10 healthy individuals as controls. The position of the marker mutations was determined with the Mutation Surveyor software version 5.1.2. DnaSP version 5.10, MEGA version 7.014, and the program Arlequin version 3.1 were used to highlight the parameters of variability, differentiation, and the demo-genetic evolution of our study populations. The pathogenicity of the mutations was determined through Polyphen2, TAMISER, and ClinVar. Results: Our results showed the presence of a recurrent mutation of the TP53 gene in both tumor and healthy tissue where proline was replaced with arginine at codon 72. This mutation was predicted to be benign. The presence of this mutation in healthy tissue can be considered a relatively late event in colorectal tumorigenesis. In addition, the P47L, D49A, W53S, and D48G mutations appeared to be suspicious because they were predicted to be potentially damaging. This finding suggests the genes’ involvement in the pathology of CRCs in our study population. The cancer tissue sequences contained an average of 2.59 nucleotide differences that resulted in amino acid changes. The Nei genetic distance confirms this variability between tumor tissues. Conclusion: These results suggest that variants in exon 4 of the TP53 gene may contribute to the development of CRCs. These mutations could constitute molecular markers in CRC and possibly help in the development of early diagnosis

Patient-derived xenograft models for gastrointestinal tumors: A single-center retrospective study.

Patient-derived xenograft (PDX) models have shown a great efficiency in preclinical and translational applications. Gastrointestinal (GI) tumors have a strong heterogeneity, and the engraftment rate of PDX models remarkably vary. However, the clinicopathological and molecular characteristics affecting the engraftment rate still remain elusive. A total of 312 fresh tumor tissue samples from patients with GI cancer were implanted into immunodeficient mice. The median follow-up time of patients was 37 months. Patients' characteristics were compared in terms of PDX growth and overall survival. PDX models of 3-6 generations were used for drug evaluation. In total, 171 (54.8%, 171/312) PDX models were established, including 85 PDX models of colorectal cancer, 21 PDX models of esophageal cancer, and 65 PDX models of gastric cancer. Other than tumor site, histology, differentiation degree, and serum alpha-fetoprotein (AFP) level, no significant differences were found between transplantation of xenografts and patients' characteristics. For patients who had undergone neoadjuvant therapy, the incidence of tumor formation was higher in those with progressive disease (PD) or stable disease (SD). In gastric cancer, the results showed a higher transplantation rate in deficient mismatch repair (dMMR) tumors, and Ki-67 could be an important factor affecting the engraftment rate. The gene mutation status of RAS and BRAF, two important molecular markers in colorectal cancer, showed a high degree of consistency between patients' tumors and PDXs. However, no significant effects of these two mutations on PDX engraftment rate were observed. More importantly, in this study although KRAS mutations were detected in two clinical cases, evident tumor inhibition was still observed after cetuximab treatment in both PDX models and patients. A large-scale PDX model including 171 cases was successfully established for GI tumors in our center. The relationship between clinicopathological and molecular features and engraftment rates were clarified. Furthermore, this resource provides us with profound insights into tumor heterogeneity, making these models valuable for PDX-guided treatment decisions, and offering the PDX model as a great tool for personalized treatment and translation research.

Effect of Tumor Location on Clinicopathological and Molecular Markers in Colorectal Cancer in Eastern China Patients: An Analysis of 2,356 Cases.

Colorectal cancer (CRC) has become a major health concern in China due to its increasing incidence and mortality. This study aimed to clarify the relationship between tumor locations and the clinicopathological molecular marker features in eastern China CRC patients. We continuously collected data on 2,356 CRC patients who underwent surgical resection from January 2017 to April 2019. Right-sided colorectal cancer (RCC), was located from the cecum to the transverse colon and left-side colorectal cancer (LCRC) was located from the splenic flexure to the rectum. The clinicopathological indices (including age, sex, pTNM stage, mucinous production, and distant metastasis) and frequency of molecular markers such as KRAS, NRAS, BRAF, and microsatellite instability (MSI) were statistically analyzed between the RCC and LCRC groups. The associations between clinicopathological characters and molecular markers were also investigated. LCRC and RCC proportions in eastern China CRC patients were 81.75% and 18.25%, respectively. RCC (vs. LCRC) was more frequently observed with higher frequencies of MSI-high (MSI-H) and BRAF mutations in female and younger patients, and was closely associated with metastasis, poor differentiation, and mucinous tumors. Tumor location also showed significant differences in bowel wall infiltration degree and pTNM stage. Mutation rates of KRAS, NRAS, MSI, and BRAF were 40.15%, 3.85%, 6.31%, and 2.30%, respectively. Patients with a KRAS mutation tended to be female, had mucinous, perineural invasive, and polypoid tumor. Those with NRAS mutation tended to develop well-differentiated ulcerative tumors. The BRAF mutation was more relevant with lymph node involvement, deeper infiltration of the bowel wall, mucinous, poorly-differentiated tumor with thrombus, and perineural invasion. Furthermore, MSI-H was more commonly found in younger patients with deeper bowel wall infiltration and a poorly-differentiated polypoid tumor, whereas MSS patients tended to develop lymph node involvement, and a mucinous and perineural invasive tumor. In our study, we found that LCRC and RCC showed different features on the clinicopathological and molecular markers in eastern China CRC patients. Since our data differ from those of Western countries and other regions in China, further studies are required to clarify the regional differences of the clinicopathological and molecular markers in CRC patients.

Colorectal cancer: a multifaceted disease.

We are pleased to present this focused issue on “Molecular Markers in Colorectal Cancer”. Advances in molecular profiling and bioinformatics have opened a frontier of exponentially increasing new knowledge that has accelerated the promise of precision oncology.

Identification and Interaction Analysis of Molecular Markers in Colorectal Cancer by Integrated Bioinformatics Analysis.

BackgroundColorectal cancer (CRC) is an extremely common gastrointestinal malignancy.Material/MethodsThree mRNA and 2 microRNA microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and microRNAs (DEMs) were obtained. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) program was utilized to perform gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Protein–protein interaction (PPI) network analysis was performed with the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape and Molecular Complex Detection (MCODE). Kaplan-Meier curves were plotted to determine overall survival (OS) estimates. DEMs targets were predicted by miRWalk. Quantitative reverse transcription polymerase chain reaction (QRT-PCR) was utilized to detect the expression of genes and microRNAs.ResultsA total of 264 DEGs and 8 DEMs were obtained. GO analysis revealed that the DEGs were enriched in terms of cell structure, digestion, receptor binding, and extracellular material (ECM). KEGG pathway analysis showed that the DEGs were enriched in ECM interaction and mineral absorption. Additionally, a PPI network consisting of 181 nodes and 450 edges was established. Three modules with 38 high-degree hubs were extracted from the PPI network and found to be involved in pathways such as chemokine signaling. Five DEGs located in the network of DEM-DEG pairs were associated with the overall survival of CRC patients. Furthermore, hsa-miR-551b was demonstrated to be significantly down-regulated in CRC tissues.ConclusionsThe key biomarkers could provide new clues for CRC.

Competing endogenous RNA network crosstalk reveals novel molecular markers in colorectal cancer.

The competing endogenous RNA networks play a pivotal role in cancer diagnosis and progression. Novel properstrategies for early detection of colorectal cancer (CRC) are strongly needed. We investigated a novel CRC-specific RNA-based integrated competing endogenous network composed of lethal3 malignant brain tumor like1 (L3MBTL1) gene, long non-coding intergenic RNA- (lncRNA RP11-909B2.1) and homo sapiens microRNA-595 (hsa-miRNA-595) using in silico data analysis. RT-qPCR-based validation of the network was achieved in serum of 70 patients with CRC, 40 patients with benign colorectal neoplasm, and 20 healthy controls. Moreover, in cancer tissues of 20 of the 70 CRC cases were involved in the study. The expression of RNA-based biomarker network in both CRC and adjacent non-tumor tissues and their correlation with the serum levels of this network members was investigated. Lastly, the expression levels of the chosen ceRNA was verified in CRC cell line. Our results revealed that the three RNAs-based biomarker network (long non-coding intergenic RNA-[lncRNA RP11-909B2.1], Homo sapiens microRNA-595 [hsa-miRNA-595], and L3MBTL1 mRNA), had high sensitivity and specificity for discriminating CRC from healthy controls and also from benign colorectal neoplasm. The data suggest that among these three RNAs, serum lncRNA RP11-909B2.1 could be a promising independent prognostic factors in CRC. The circulatory RNA based biomarker panel can act as potential biomarker for CRC diagnosis and prognosis.

Current Tissue Molecular Markers in Colorectal Cancer: A Literature Review.

Background Colorectal cancer (CRC) is one of the most spread neoplasia types all around the world, especially in western areas. It evolves from precancerous lesions and adenomatous polyps, through successive genetic and epigenetic mutations. Numerous risk factors intervene in its development and they are either environmental or genetic. Aim of the Review Alongside common screening techniques, such as fecal screening tests, endoscopic evaluation, and CT-colonography, we have identified the most important and useful biomarkers and we have analyzed their role in the diagnosis, prevention, and prognosis of CRC. Conclusion Biomarkers can become an important tool in the diagnostic and therapeutic process for CRC. But further studies are needed to identify a noninvasive, cost-effective, and highly sensible and specific screening test for their detection and to standardize their use in clinical practice.

Segmental distribution of some common molecular markers for colorectal cancer (CRC): influencing factors and potential implications.

Proximal and distal colorectal cancers (CRCs) are regarded as distinct disease entities, evolving through different genetic pathways and showing multiple clinicopathological and molecular differences. Segmental distribution of some common markers (e.g., KRAS, EGFR, Ki-67, Bcl-2, COX-2) is clinically important, potentially affecting their prognostic or predictive value. However, this distribution is influenced by a variety of factors such as the anatomical overlap of tumorigenic molecular events, associations of some markers with other clinicopathological features (stage and/or grade), and wide methodological variability in markers' assessment. All these factors represent principal influences followed by intratumoral heterogeneity and geographic variation in the frequency of detection of particular markers, whereas the role of other potential influences (e.g., pre-adjuvant treatment, interaction between markers) remains rather unclear. Better understanding and elucidation of the various influences may provide a more accurate picture of the segmental distribution of molecular markers in CRC, potentially allowing the application of a novel patient stratification for treatment, based on particular molecular profiles in combination with tumor location.

Prognostic relevance of microsatellite instability in pT3N0M0 colon cancer: a population-based study.

Although surgery alone represents a curative approach for patients with pT3N0M0 colon cancer, about 15-20% of these patients develop a relapse of disease. Microsatellite instability (MSI) is one of the most important molecular markers in colorectal cancer. The aim of this study was to investigate the prognostic relevance of MSI in all pT3N0M0 tumors recorded in the Cancer Registry of the Province of Modena--(Northern Italy) within the 2002-2006 period in patients who showed a relapse of disease during the 5-year period of follow-up (59 cases). They were compared to 59 controls similar in clinical and pathological features but with good prognosis. None of the subjects received adjuvant chemotherapy. MSI status was tested using BAT25, BAT26, NR24, and CAT25 fluorescent-labeled mononucleotide markers. The overall prevalence of MSI was 12.7% (15 of 118 cases). MSI was detected mainly in mucinous adenocarcinoma (p < 0.003), in high-grade tumors (p < 0.008), in right-sided neoplasms (p < 0.005), and in patients with a better prognosis, though the difference was not statistically significant (11/59 patients -18.6% vs 4/59 patients -6.7%; OR 0.36 CI 95% 0.11-1.15; p = 0.08). However, in multivariate analysis, MSI status becomes the strongest independent factor associated with relapse (OR 0.21, CI 95% 0.06-0.81; p = 0.023), together with mucinous histological type (OR 0.40, CI 90% 0.18-0.92). MSI is a relevant prognostic factor in stage pT3N0M0 colon cancer suitable to discriminate those patients with a high risk of relapse.

Cell adhesion molecules have prognostic potential in colorectal carcinoma

Background The cadherin–catenin complex is vital cell adhesion molecules and it plays a fundamental role in maintaining the cells differentiation and the normal architecture of epithelial tissues (1). Consequently, the disruption of this complex has been shown in carcinomas and correlated with various pathologic and clinical features. This study seeks for molecular markers in colorectal cancer (CRC) that defines those patients at high risk of recurrence and poor outcome. This study is aimed to assess the expression of selected group of cadherin-catenin; E-cadherin, N-cadherin, a-catenin and b-catenin in subset of primary CRC and determine their relation to different clinicopathological factors and survival (2).

Molecular markers in colorectal cancer: clinical relevance in stage II colon cancer

SUMMARY Colorectal cancer is the second most common cause of cancer death in developed countries. Adjuvant chemotherapy is standard for stage III colorectal cancer but its use in stage II is controversial. Several clinicopathological factors have been described to define a high-risk group among stage II colon cancers, which can aid the selection of patients who may benefit from chemotherapy. Local tumor invasion (T4), high histological grade, obstruction and perforation at diagnosis, and number of lymph nodes removed are the most widely accepted factors. Several molecular factors have been also investigated as prognostic candidate biomarkers. DNA ploidy, KRAS and TP53 mutations, thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, loss of heterozygosity on chromosome 18q and microsatellite instability have been widely investigated. The aim of this review is to analyze the current evidence and clinical applications of the classical molecular biomarkers as well as new ones such as BRAF, circulating tumor cells, genome expression signatures and DNA methylation.

Phase II trial of target-guided personalized chemotherapy in first-line metastatic colorectal.

3543 Background: Chemotherapy (Ch) options for patients (pts) with colorectal cancer (CRC) have increased in the last years. However, there are no validated prospective molecular markers in CRC to select which agents are better to treat any individual case. The aim of this study was to determine the efficacy in terms of progression free survival (PFS) of a biomarker panel to guide treatment selection in this setting. Methods: Treatment naive, ECOG 0-1, metastatic CRC pts were accrued. Pts were prospectively analyzed with a predefined set of 10 molecular targets, including: KRAS, BRAF, and PI3K mutations and Topoisomerase-1(Top-1), ERCC-1, Thymidylate synthase (TS) and Thymidine phosphorylase (TP) expression by inmunohistochemistry ( IHC) performed in a tumor biopsy. Ch combination schema plus Cetuximab (C) or Bevacizumab (B) at standard doses was customized based on: Topo-1 +:Irinotecan (I). Topo-1- and ERCC-1 -:Oxaliplatin(O). Topo-1- and ERCC1 +:investigator option (I or O). TS -:Fluoropyrimidines (FP).TS +:No FP. TP -:5-FU, TP +:Capecitabine. Maintenance C or B treatment was allowed. Primary outcome measure was PFS. Results: 74 pts were accrued and all of them received biomarker guide treatment. All of them began personalized. Interim analysis on 61 pts (38 males, median age 65) showed.Topo-1 + in 33 pts (54%),ERCC-1- in 36( 59%) TS + in 44 (73%), TP – in 61 ( 100%), K-ras nativein 34 ( 55%), BRaf mutated in 2 (3,2%). With a median follow up time of 9,1 months (m). Median PFS (95% CI) is 8,6 (6,2-10,9) m, with a 41,3% (27,4-55,2) 12mPFS . Overall clinical benefit (Response + Stabilizations) was 74,5% (65,6-83,4).Toxicities Grade ≥ 3 included 18% neutropenia, 4,9% asthenia and 3,3% anemia. 12 pts (23%) received loco-regional treatment ( surgery or radiosurgery). Median Overall survival has not been reached. Conclusions: Target- Guided Personalized Ch in first line CRC pts is feasible and results in promising PFS with low toxicity. Update of final results and more detailed data will be presented. Clinical trial information: NCT01453257.

PD-0017 Phase II Trial of Target-Guided Personalized Chemotherapy in First Line Metastatic Colorectal

ABSTRACT Introduction Chemotherapy (Ch) options for patients (pts) with colorectal cancer (CRC) have increased in the last years. However, there are no validated prospective molecular markers in CRC to select which agents are better to treat any individual case. The aim of this study was to determine the efficacy in terms of progression free survival (PFS) of a biomarker panel to guide treatment selection in this setting. Methods Treatment naive, ECOG 0-1, metastatic CRC pts were accrued. Pts were prospectively analyzed with a predefined set of 10 molecular targets, including: KRAS, BRAF, and PI3K mutations and Topoisomerase-1(Top-1), ERCC-1, Thymidylate synthase (TS) and Thymidine phosphorylase (TP) expression by immunohistochemistry (IHC) performed in a tumor biopsy. Ch combination schema plus Cetuximab (C) or Bevacizumab (B) at standard doses was customized based on: Topo-1 +: Irinotecan (I). Topo-1- and ERCC-1 -: Oxaliplatin(O). Topo-1- and ERCC1 +: investigator option (I or O). TS -: Fluoropyrimidines (FP).TS +: No FP. TP -: 5-FU, TP +: Capecitabine. Maintenance C or B treatment was allowed. Primary outcome measure was PFS. Results 74 pts were accrued and all of them received biomarker guide treatment. All of them began personalized. Interim analysis on 61 pts (38 males, median age 65) showed Topo-1 + in 33 pts (54%), ERCC-1- in 36 (59%) TS + in 44 (73%), TP – in 61 (100%), K-ras native in 34 (55%), BRaf mutated in 2 (3.2%), with a median follow up time of 9.1 months (m). Median PFS (95% CI) is 8.6 (6.2-10.9) m, with a 41.3% (27.4-55.2) 12 m PFS. Overall clinical benefit (Response + Stabilizations) was 74.5% (65.6-83.4).Toxicities Grade ≥ 3 included 18% neutropenia, 4.9% asthenia and 3.3% anemia. 12 pts (23%) received loco-regional treatment (surgery or radiosurgery). Median Overall survival has not been reached. Conclusion Target-Guided Personalized Ch in first line CRC pts is feasible and results in promising PFS with low toxicity. Update of results and more detailed data will be presented.

Circulating MicroRNA in Digestive Tract Cancers

d t For many decades, cell-free nucleic acids have been known to be present in peripheral blood. Several tudies have identified tumor-specific and/or tumor-assoiated alterations in the circulating nucleic acids of paients with various cancers. In recent years, cell-free miroRNA (miRNA) have been stably detected in the plasma nd serum, like other molecules; their presence in the lood has attracted the attention of researchers due to heir potential use as valuable blood biomarkers.1 MiRNAs are short, noncoding RNAs that play important roles in various physiologic and developmental processes. The mature miRNAs are produced from long primary transcripts through 2 sequential cleavage steps. The long primary miRNA transcript is cleaved by the Drosha complex in the nucleus, generating intermediate precursor miRNA. Precursor miRNA is transported by exportin-5 from the nucleus into the cytoplasm, and then subjected to further cleavage by a Dicer RNAase III enzyme, generating a short double-strand miRNA. One strand (guided strand) of mature miRNA is then incorporated into the RNA-induced silencing complex and subsequently hybridize to the 3=-untranslated region of their target mRNAs to repress translation or degrade these mRNAs. Thus, a single miRNA can influence the expression of hundreds of genes and allow them to function in a coordinated manner. Therefore, miRNAs have been implicated as key molecules in all cellular processes. Numerous studies have shown that alterations in miRNA expression correlate with various diseases, including the development and progression of cancer, and some miRNAs can function as oncogenes or tumor suppressors. These findings have opened up a new and interesting field in the diagnosis of cancer and the treatments of cancer patients. Mitchell et al2 first demonstrated that circulating miRNAs had the potential to be new biomarkers in patients with solid cancers. In recent years, several papers have demonstrated that circulating miRNAs can also be detected in the peripheral blood of patients with digestive tract cancers. Although the origins and physiologic functions of cell-free miRNAs in the blood remain to be fully elucidated, a noninvasive assay for miRNAs should be developed to exploit these molecules as potential diagnostic and prognostic biomarkers. This assay undoubtedly contributes to an improvement in the clinical outcomes of cancer patients. In this article, we review the current state of biological and clinical research regarding circulating miRNAs of digestive tract cancer patients and discuss the future perspectives.

Efficacy of first-line systemic treatment in correlation with BRAF V600E and different KRAS mutations in metastatic colorectal cancer - a single institution retrospective analysis.

BackgroundKRAS mutation status in codons 12 and 13 is recognized as a predictive factor for resistance to anti-EGFR monoclonal antibodies. Despite having a wild type KRAS (wt-KRAS), not all patients with wt-KRAS respond to anti-EGFR antibody treatment. Additional mechanisms of resistance may activate mutations of the other main EGFR effectors pathway. Consequently, other molecular markers in colorectal cancer are needed to be evaluated to predict the response to therapy.Patients and methodsIn this retrospective study, objective responses (OR), time to progression (TTP), overall survival (OS) were analyzed in 176 metastatic colorectal cancer (mCRC) patients treated with first-line chemotherapy in combination with monoclonal antibodies in respect of KRAS status in codons 12 and 13 and BRAF mutational status.ResultsThe KRAS mutations were found in 63 patients (35.8 %), the KRAS mutation in codon 12 in 53 patients (30.1%) and the KRAS mutation in codon 13 in 10 patients (5.7%). The BRAF V600E mutation was detected in 13 of 176 patients (7.4%). In the subgroup of mCRC patients having wt-KRAS and wild type BRAF (wt-BRAF), the objective response rates were higher (OR 54.0% ,CR 14.7%, PR 39.3%) than in the patients with wt-KRAS and mt-BRAF (OR 38.5%,CR 15.4%, PR 23.1%), the difference was not statistically significant (p= 0.378). Median OS in patients with wt-KRAS wt-BRAF, and in patients with wt-KRAS mt-BRAF, was 107.4 months and 45 months, respectively. The difference was statistically significant (p= 0.042). TTP in patients with wt-KRAS wt-BRAF, and in patients with wt-KRAS mt-BRAF, was 16 months and 12 months, respectively. The difference was not statistically significant (p= 0.558).ConclusionsPatients with BRAF V600E mutation have statistically significantly worse prognosis than the patients with wt-BRAF and progress earlier during treatment. The definitive role of the BRAF V600E mutation as a prognostic and predictive factor for the response to anti-EGFR monoclonal antibodies needs to be analyzed in large prospective clinical studies.

Use of combined biomarkers analysis to predict response to chemotherapy in colorectal cancer: A single-institution feasibility study

11074 Background: Treatment options for patients (pts) with colorectal cancer (CRC) have increased in the last years. However, there are no validated prospective molecular markers in CRC to select which agents are better to treat any individual case. The aim of this study was to determine the feasibility of developing an implementing a biomarker panel to guide treatment selection in this setting. Methods: Colorectal cancer tumors were prospectively analyzed with a predefined set of 11 molecular targets, including: KRas and PI3K mutations, EGFR amplification (FISH), and ERCC-1, TS, TP expression by IHC. Clinical characteristics and response to chemotherapy were registered. To establish the utility of this panel, we determine as congruent-treatment if the panel predict the best treatment in patients with more of 1 chemotherapy line and no-congruent-treatment if do not. Results: A total of 84 patients were studied. Only 6 % required a repeated biopsy to obtain sufficient tumor for marker analysis. In 81 % of patients was feasible to study almost 8/11 targets. There were 29 pts (39%) with KRas mutant CRC; 3 pts with PI3K mutations (4%, all of them with KRas mutation); and 2 patients with EGFR amplification. ERCC-1 was positive in 5/78 (6.4%) and TS was positive in 47%. None of 54 pts had TP positivity. Clinical floow up was available in 66 pts (44 males, median age 59, 93% ECOG 0–1). Nineteen patients had early CRC; 23 with metastatic CRC treated with a first line chemotherapy and 24 with advanced CRC treated with 2 or more prior regimens. In this last group for whom the response to multiple agents is known, the panel predictive the most effective treatment in 14 of 24 cases. Conclusions: This targeted-therapy-panel is feasible to implement and should be explore to predict treatment response to CRC . No significant financial relationships to disclose.

Expression of P53, P27 and KI‐67 in colorectal cancer patients of various ethnic origins: Clinical and tissue microarray based analysis

This study was conducted to determine survival according to the expression of molecular markers in colorectal cancer (CRC) patients of various ethnic origins. Resection of primary tumor was conducted on 171 patients with CRC. Corresponding archived paraffin-embedded blocks were retrieved and tissue microarray (TMA) constructed. Immunohistochemical staining of the TMA for p53, p27 and Ki-67 was quantified by two independent pathologists. Survival was analyzed using the Kaplan-Meier product limit method. With a median follow-up of 65 months, 56 patients (32.7%) died of disease. AJCC stage correlated with disease-free (DFS, P < 0.0001) and overall survival (OS, P < 0.0001). IHC staining was positive for Ki-67 in 77.4%, p53 in 55.8% and p27 in 54.2% of patients. Primary tumor marker expression did not correlate with DFS or OS. The 5-year DFS for Ashkenazi Jews was 75%, significantly higher than Sephardic Jews (SJ) 64% and Palestinian Arabs (PA) 38%, P = 0.001. Ethnicity among Ashkenazi and SJ and PA appears to have a significant impact on disease outcome in patients with CRC patients, while primary tumor expression of p53, p27 and Ki-67 was unrelated to disease outcome.

Predictive Molecular Markers for Colorectal Cancer Patients With Resected Liver Metastasis and Adjuvant Chemotherapy

The aims of the study were to evaluate the predictive value of 8 candidate molecular markers for colorectal cancer (CRC) patients receiving hepatic arterial infusion (floxuridine [FUDR] and dexamethasone) and systemic irinotecan (CPT11) post resection of liver metastasis. RNA was extracted from microdissected tumor cells of fixed and embedded specimens of resected liver metastases (94 cases) and analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) for thymidine phosphorylase, dihydropyrimidine dehydrogenase, thymidylate synthase, uridine phosphorylase, uridine/cytidine (monophospho)kinase, Bcl-2 related protein, Cyclin-D1, and Survivin expression. Uni- and multivariate statistical analyses and an explorative hierarchical clustering analysis of quantitative RT-PCR data were performed for overall survival and recurrent disease. After adjustment for multiple clinicopathologic parameters, none of the markers were significantly associated with overall survival (except, marginally, Cyclin-D1; P = .06) or extrahepatic recurrence. However, high Survivin (P = .03) and Cyclin-D1 (P = .05) levels were predictive for hepatic recurrence. Hierarchical cluster analysis identified 7 of 94 patients associated with lower hepatic recurrence (P < .001). This patient group was characterized by low Cyclin-D1 and Survivin messenger RNA levels, both genes also clustering together. Cyclin-D1 and Survivin messenger RNA analyzed by standardized, quantitative RT-PCR are predictive markers for CRC patients receiving hepatic arterial infusion (FUDR/dexamethasone) and systemic CPT11 post resection of liver metastasis. Moreover, our exploratory hierarchical cluster analysis of quantitative RT-PCR data supports its potential as an application to define clinically relevant patient subgroups.

Molecular markers in colorectal cancer: genetic bases for a customised treatment

Colorectal cancer (CRC) is the second leading cause of cancer death in Western countries. CRC treatment is based on the employment of three chemotherapeutic drugs, including 5-fluorouracil, oxaliplatin and irinotecan, and the use of recently incorporated targeted agents directed to vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR). The approval of these biologicals and of others to come holds great promise for the improvement of patient outcome. The molecular bases for this lethal disease have been extensively investigated, laying the foundations for a rational and customised treatment approach, expanding the therapeutic index of current drugs and easing the incorporation of new molecules. Individual markers have been mainly investigated based on drug targets and metabolism. Also, the increasing availability of highthroughput technologies has prompted the opportunity for blind studies capable of screening new markers and of identifying the specific oncogenic pathways responsible for drug resistance in a given patient. An updated review of the field is presented in this article.

Molecular markers in colorectal cancer

Molecular markers in colorectal cancer