Identification of an Excellent PCR-Based Classifier to Predict Tumor Relapse in Stage II/III Colorectal Cancer and Its Clinical Application Irrespective of Consensus Molecular Subtypes

2019 ◽  
Author(s):  
Guozeng Xu ◽  
Zhan Song ◽  
Zhaohua Gong ◽  
Jian Chen
2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e14613-e14613
Author(s):  
Laia Pare-Brunet ◽  
Rebeca Sanz-Pamplona ◽  
Adriana Lopez-Doriga ◽  
Antoni Berenguer-Llergo ◽  
Susanna Ausso ◽  
...  

e14613 Background: Aberration of normal genetic and epigenetic patterns occurs at early stages of colorectal cancer (CRC) and accumulates throughout cancer progression. To characterize pre-metastatic tumors, a series of stage II, microsatellite stable, colon tumors and their paired mucosa were profiled on RNA expression and DNA methylation microarrays ( www.colonomics.org ). Our aim is to define molecular subtypes based on recurrent gene mutations, methylation and expression profiles, and explore if these molecular subtypes are associated to patients’ prognosis. Methods: We have sequenced exomes (Illumina Genome Analyzer) of a subset of 42 COLONOMICS normal-tumor paired samples (21 good and 21 bad prognosis). Variants identified in normal tissue were used to filter SNPs. DNA methylation (Infinium Human Methylation 450k) and RNA expression (Affymetrix U219) data from those samples were used in this analysis. Correlation was used to assess the association between tumor mutations and differentially expressed/methylated genes. Significant genes were subsequently used to perform tumor clustering. Results: Exome analysis revealed a mean of 150 somatic mutations per sample. From these, 12 variants were recurrently mutated (KRAS, TP53, etc) in more than 3 tumors that were used to define tumor subtypes based on gene methylation/expression patterns. We obtained 12 profiles that clearly identified the cluster of mutated samples. For some profiles, the cluster only includes those tumors with the mutation. Interestingly, some clusters included the mutated samples and additional tumors showing the same phenotype despite not having the mutation. For each mutation, the overlapping between the differently methylated/expressed genes ranged from 14 to 200 common genes. When combining data from the three platforms two main CRC molecular subtypes emerge; each of which shows molecular heterogeneity but no association with prognosis. Conclusions: Mutational status is associated with gene methylation and expression patterns in CRC patients. Although none of these clusters was associated with prognosis, different groups of tumors could be related to distinctive pathways, which may reveal useful as therapeutic targets.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3514-3514 ◽  
Author(s):  
S. Rim Kim ◽  
Nan Song ◽  
Greg Yothers ◽  
Patrick Gavin ◽  
Carmen Joseph Allegra ◽  
...  

3514 Background: The predictive value of tumor sidedness in colorectal cancer is currently of interest especially in metastatic setting for anti-EGFR therapy response. We tested whether intrinsic molecular subtype classification predictive of treatment benefit in stage II/III colon cancer is an independent novel marker in association with tumor sidedness. Methods: All available cases included in the NSABP/NRG C-07 trial for which we had both gene expression data and anatomical data (n=1603) were used to determine the molecular subtypes using the following classifiers; the Colorectal Cancer Assigner (CRCA), the Colon Cancer Subtypes (CCS) and the Consensus Molecular Subtypes (CMS). Frequency of tumor sidedness in each subtype and recurrence-free survival were analyzed. Results: Intrinsic subtypes were differentially distributed in right- and left-colon tumors with the exception of the stem-like or CMS4 (mesenchymal) subtype (Table 1). Sidedness was not associated with prognosis (p=0.82, HR: 1.022 [CI: 0.851-1.227]) or prediction of patients with greater benefit from oxaliplatin when combined with 5-Fu+LV (interaction p=0.484). Conclusions: Although tumor sidedness is associated with distribution of intrinsic subtypes in stage II/III colon cancer, it is not predictive of survival benefit from oxaliplatin in C-07. Support: -180868, -180822, U24-CA196067; HI13C2162; PA DOH; Sanofi-Synthelabo Clinical trial information: NCT00004931. [Table: see text]


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 4041-4041
Author(s):  
R. D. Kennedy ◽  
V. Proutski ◽  
A. Tanney ◽  
A. Winter ◽  
J. M. Black ◽  
...  

4041 Background: The discovery and widespread acceptance of molecular subtypes in breast cancer has changed the way that this disease is viewed. Similarly, we have focussed on stage II colorectal cancer where 20–25% of patients are at risk of recurrent disease following surgery. There are currently several types of colorectal cancer recognised by histopathological methods, however, little has been published regarding disease classification at a molecular level. Methods: We have taken an unbiased approach to the molecular classification of colorectal cancer. Using a colorectal cancer disease specific microarray platform we have performed expression profiling and bioinformatic analysis of 500 formalin fixed and paraffin embedded (FFPE) stage II colorectal cancer samples, in order to identify and characterise molecular subtypes. Results: We have identified molecular subtypes for colorectal cancer. One of these subtypes is enriched with tumours with microsatellite instability (MSI) that are predominantly proximal, mucinous and poorly differentiated. It is notable that while MSI is generally accepted to be associated with a good prognosis, we have found both good and poor prognosis patients within this subtype. A second subtype contains tumors with a low CpG island methylator phenotype. Another subtype is defined by an expression pattern consistent with activation of tumor suppressors. The remaining subtypes are newly identified. Conclusions: We have identified molecular subtypes in colorectal cancer. We will present how knowledge about these subtypes may affect patient management and may be used to guide the development of novel therapeutic strategies. [Table: see text]


2019 ◽  
Vol 65 (5) ◽  
pp. 701-707
Author(s):  
Vitaliy Shubin ◽  
Yuriy Shelygin ◽  
Sergey Achkasov ◽  
Yevgeniy Rybakov ◽  
Aleksey Ponomarenko ◽  
...  

To determine mutations in the plasma KRAS gene in patients with colorectal cancer was the aim of this study. The material was obtained from 44 patients with colorectal cancer of different stages (T1-4N0-2bM0-1c). Plasma for the presence of KRAS gene mutation in circulating tumor DNA was investigated using digital droplet polymerase chain reaction (PCR). KRAS mutations in circulating tumor DNA isolated from 1 ml of plasma were detected in 13 (30%) patients with cancer of different stages. Of these, with stage II, there were 3 patients, with III - 5 and with IV - 5. Patients who did not have mutations in 1 ml of plasma were analyzed for mutations of KRAS in circulating tumor DNA isolated from 3 ml of plasma. Five more patients with KRAS mutations were found with II and III stages. The highest concentrations of circulating tumor DNA with KRAS mutation were found in patients with stage IV. The increase in plasma volume to 3 ml did not lead to the identification of mutations in I stage. This study showed that digital droplet PCR allows identification of circulating tumor DNA with the KRAS mutations in patients with stage II-IV of colon cancer. The results can be used to determine the degree of aggressiveness of the tumor at different stages of the disease, but not the 1st, and it is recommended to use a plasma volume of at least 3 ml.


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