Project description:KRAS mutation is a negative predictive factor for treatment with anti-epidermal growth factor receptor (EGFR) antibodies in metastatic colorectal cancer (mCRC). Novel predictive markers are required to further improve the selection of patients for this treatment. Here, we assessed the influence of modification of KRAS by gene copy number aberration (CNA) and microRNAs (miRNAs) in correlation to clinical outcome in mCRC patients treated with cetuximab in combination with chemotherapy and bevacizumab. Formalin-fixed paraffin-embedded primary tumour tissue was used from 34 mCRC patients in a phase III trial, who were selected based upon their good (n=17) or poor (n=17) progression-free survival (PFS) upon treatment with cetuximab in combination with capecitabine, oxaliplatin, and bevacizumab. Gene copy number at the KRAS locus was assessed using high resolution genome-wide array CGH and the expression levels of 17 miRNAs targeting KRAS were determined by real-time PCR. Good response was associated with 12p12.1 copy number loss, even in patients with a KRAS mutation, while copy number gain in wild-type KRAS patients was correlated with a poor response. In KRAS mutated tumours increased miR-200b and decreased miR-143 expression were associated with a good response. In wild-type KRAS patients, miRNA expression did not predict response in a multivariate model. Thus, assessment of KRAS CNA and miRNAs targeting KRAS might further optimize the selection of patients eligible for anti-EGFR therapy. Copy number detection was performed using NimbleScan and Nexus software Formalin-fixed paraffin-embedded primary tumour tissue was used from 34 metastisized colorectal cancer patients in a phase III trial (CKTO 2005-02; ClinTrials.gov NCT00208546) of the Dutch Colorectal Cancer Group (DCCG), who were selected based upon their good (n=17) or poor (n=17) progression-free survival (PFS) upon treatment with cetuximab in combination with capecitabine, oxaliplatin, and bevacizumab.

Project description:Lymph-node (LN) metastases predict for high recurrence rates in breast cancer patients. Eradication of micro-metastatic tumor cells is the primary goal of adjuvant systemic treatment. Decisions regarding systemic treatment depend largely on primary tumor characteristics rather than on characteristics of their LN metastases. However, it remains unclear to what extent LN metastases, having already metastasized locally, resemble their primary breast tumors and as such will be eradicated by the systemic therapy chosen. In this study we investigated the genetic differences between primary breast cancers and their paired LN metastases using array comparative genomic hybridization analyses on a high resolution 720K Nimblegen platform. Thus far, no metastasis-specific genomic aberrations have been identified. We hypothesized that this is due to low-resolution platforms and lack of stratification on breast cancer subtypes (specifically, triple-negative (TN) versus luminal). Furthermore, we speculated that as TN tumours are known to be more genetically unstable, their LN metastases would show an increase in random copy number aberrations (CNAs). Therefore, we studied 10 primary TN breast tumour–LN pairs and 10 luminal pairs and found that all LN metastases clustered nearest to their matched tumour except for two. These two were explained by poor hybridization quality and, interestingly, the presence of two histological components in one tumour. We found no significantly altered CNAs between pairs in the whole group, nor when subdivided over subtypes; neither did we find a CNA increase in LN metastases compared to primary tumours within the TN subgroup, suggesting most CNAs are functional and not random. Our findings suggest a strong clonal relationship between primary breast tumours and its LN metastases and support the use of the primary tumor characteristics to guide adjuvant systemic chemotherapy in breast cancer patients, since primary tumors and their subsequent LN metastases seem remarkably similar, at least prior to treatment. The experiment contains 27 paired primary breast cancer samples with their lymph node metastases, analysed on a 135K whole genome CGH array

Project description:Lymph-node (LN) metastases predict for high recurrence rates in breast cancer patients. Eradication of micro-metastatic tumor cells is the primary goal of adjuvant systemic treatment. Decisions regarding systemic treatment depend largely on primary tumor characteristics rather than on characteristics of their LN metastases. However, it remains unclear to what extent LN metastases, having already metastasized locally, resemble their primary breast tumors and as such will be eradicated by the systemic therapy chosen. In this study we investigated the genetic differences between primary breast cancers and their paired LN metastases using array comparative genomic hybridization analyses on a high resolution 720K Nimblegen platform. Thus far, no metastasis-specific genomic aberrations have been identified. We hypothesized that this is due to low-resolution platforms and lack of stratification on breast cancer subtypes (specifically, triple-negative (TN) versus luminal). Furthermore, we speculated that as TN tumours are known to be more genetically unstable, their LN metastases would show an increase in random copy number aberrations (CNAs). Therefore, we studied 10 primary TN breast tumour–LN pairs and 10 luminal pairs and found that all LN metastases clustered nearest to their matched tumour except for two. These two were explained by poor hybridization quality and, interestingly, the presence of two histological components in one tumour. We found no significantly altered CNAs between pairs in the whole group, nor when subdivided over subtypes; neither did we find a CNA increase in LN metastases compared to primary tumours within the TN subgroup, suggesting most CNAs are functional and not random. Our findings suggest a strong clonal relationship between primary breast tumours and its LN metastases and support the use of the primary tumor characteristics to guide adjuvant systemic chemotherapy in breast cancer patients, since primary tumors and their subsequent LN metastases seem remarkably similar, at least prior to treatment.

Project description:Lymph-node (LN) metastases predict for high recurrence rates in breast cancer patients. Eradication of micro-metastatic tumor cells is the primary goal of adjuvant systemic treatment. Decisions regarding systemic treatment depend largely on primary tumor characteristics rather than on characteristics of their LN metastases. However, it remains unclear to what extent LN metastases, having already metastasized locally, resemble their primary breast tumors and as such will be eradicated by the systemic therapy chosen. In this study we investigated the genetic differences between primary breast cancers and their paired LN metastases using array comparative genomic hybridization analyses on a high resolution 720K Nimblegen platform. Thus far, no metastasis-specific genomic aberrations have been identified. We hypothesized that this is due to low-resolution platforms and lack of stratification on breast cancer subtypes (specifically, triple-negative (TN) versus luminal). Furthermore, we speculated that as TN tumours are known to be more genetically unstable, their LN metastases would show an increase in random copy number aberrations (CNAs). Therefore, we studied 10 primary TN breast tumourM-bM-^@M-^SLN pairs and 10 luminal pairs and found that all LN metastases clustered nearest to their matched tumour except for two. These two were explained by poor hybridization quality and, interestingly, the presence of two histological components in one tumour. We found no significantly altered CNAs between pairs in the whole group, nor when subdivided over subtypes; neither did we find a CNA increase in LN metastases compared to primary tumours within the TN subgroup, suggesting most CNAs are functional and not random. Our findings suggest a strong clonal relationship between primary breast tumours and its LN metastases and support the use of the primary tumor characteristics to guide adjuvant systemic chemotherapy in breast cancer patients, since primary tumors and their subsequent LN metastases seem remarkably similar, at least prior to treatment. The experiment contains 20 paired primary breast cancer samples with their lymph node metastases, analysed on a 720 whole genome CGH array. Additionally, for one sample its two distinct histological subpopulations were analysed on the same platform.

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On-treatment Biomarkers in Metastatic Colorectal Cancer for Life

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