Mestastatic ColoRectal Cancer Clinical Trial
Official title:
A Proof-of-concept Study Investigating the Comparison of the RAS Mutational Status Between Primary Tumor and Metastasis in Patients Affected by Metastatic Colorectal Cancer on the Basis of Different Chemotherapeutic Regimens
This is a retrospective, translational, proof-of-concept study on tumor biopsies done on
patients affected by mCRC and exhibiting RAS mutation.
For each patient it will be selected the tissue biopsies of primary tumour and of paired
resected metastasis.
the study implies the subdivision into three groups with a 1:1:1 ratio.
- The first group includes patients treated with surgery of the primary tumor, neoadjuvant
chemotherapy plus bevacizumab and, finally, the surgical resection of liver metastasis.
- The second group is similar to group one, with the exception that patients were not
treated with a bevacizumab-based regimen.
- The third group, the control group, includes patients presenting with synchronous
primary tumour and metastasis resected without any preoperative systemic therapy
Genomic DNA from formalin-fixed paraffin-embedded (FFPE) tissues from the primary tumor and
metastatic lesions will be extracted. The genomic DNA will be assessed for the RAS mutational
status in a quantitative and qualitative manner using two different approaches: a real-time
PCR approach using the SensiScreen® kit (PentaBase Aps) and a next-generation sequencing
approach using the Ion Torrent platform by applying the Ion AmpliSeq™ Cancer Hotspot Panel v2
(ThermoFisher Scientific). The real-time PCR is able to provide the relative quantification
of the RAS mutant allele by comparing the Ct value of the mutation with respect to the Ct of
the reference gene. This ratio will be calculated for both the primary tumor and for the
metastasis and then compared. Ion Torrent gives directly the percentage of the mutant allele
in each sample. Furthermore, the Cancer Hotspot Panel v2 provides data (both quantitative and
qualitative) about the mutational status of additional 49 genes, including the most relevant
and frequently mutated genes in CRC (i.e.: APC, TP53, PIK3CA, BRAF and PTEN) and the relative
mutational pattern of the primary tumor and the one of the distant metastasis will be
compared.
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