Cancer Companion Diagnostics And Clinical Application Basing On Ion Torrent Platform

ObjectiveGenetic test is an important part in tumor care, especially before using targeted drugs. Thecommon method for genetic test now base on Sanger Chain Termination method. With thedeveloping of next generation sequence(NGS) technology, this faster, high-throughput,high-sensitivity method is used in clinical test. We sequence2samples of lung cancer and5samples of plasma which sampling from lung cancer patients before surgery with LifeTechnology Cancer Panel on Ion Torrrent platform. Then we find out a potential mutationwhich may cause the different efficacy of Erlotinib in two patients. The variations detecting fromplasma shows a high consistency with the tissues.Methods1. Collect samples. Extract DNA from2tissues from lung cancer patients and5plasma samplesfrom5lung cancer patients before surgery.2. Enriching target DNA fragments follows the protocol of Life Technology Cancer Panel,andsequencing after purification and library.3. Sequencing data analyse and get the variations.4. Analyse the pathway of variations in two tissue samples and find out the potential reason forthe different efficacy of Erlotinib.5. Compare the variations in five plasma samples between the variations in their tissue sampleswhich has been sequenced by Sanger and Ion Torrent to estimate the sensitivity of the method. Result1. Sensibility of the method. The variation of2tissue samples has been validated with Sangerand all comfirmed. The variations of5plasma samples compare with the Sanger result of theirtissue, and all comfirmed. The lowest rate,5.4%, could be detected.2. Significance in clinical. The variations of two tissue samples are mapped to cancer pathway.There is a non-synonymous mutation in MET may the potential reason for the ineffectiveness ofErlotinib.ConclusionWith the technology of Ion Torrent Cancer Panel, the guidance could be inferred fromcommon variaitions in EGFR, KRAS, BRAF, KIT and another genes in their pathway, such asMET, ALK, APC, PIK3CA, PTEN and so on. It could be more comprehensive. The two tissuesamples used this method and find out a potential mutation which lead two entirely differentphenotypes.The variations detected from plasma are accordance to the ones detected from their tissues.It proves that the method could be used in plasma. This achivement has a important significancein drug guidance of terminal stages of cancer.