Clinical Characteristics Of Targeted Gene For Lung Cancer Patients In Dalian And Identification Of A Novel RET Fusion And BRAF Mutation Gene

Background and SignificanceWith the increase of age,the incidence and mortality of lung cancer increases gradually all over the world,the number of male patients is more than that of the female patients,and the number of economically developed area is more than that of the remote rural areas.However,in recent years,the proportion of male and female lung cancer has changed,especially in the United States and other western economically developed countries,and the morbidity rate of female is gradually catching up with that of male.At present,the cause of lung cancer is not clear.Many research datas show that the main cause of lung cancer is smoking,smoking more than half of the male and female lung cancer patients in the world are affected by smoking.Previous reports show that the higher the smoking capacity,the earlier the smoking age,the longer the smoking time,would result in the higher the risk of lung cancer,which shows a kind of dose-effect relationship.And passive smoking is also harmful to health.The death rate of the lung cancer in smokers is about 10 times higher than that in non-smokers,and the risk of lung cancer can be reduced by quitting smoking.In addition,air pollution indoor and outdoor,occupational exposure and inheritance are also important factors which lead to lung cancer,genetic susceptibility plays a important role,especially in young patients.With the development of social economy,the increase of industrial development,the destruction of ecological environment,as well as the increase of the aging population,the incidence of lung cancer is increasing day by day.Meanwhile,the threat of lung cancer to the whole human population is also increasing day by day.Therefore,the research on the causes and the epidemiology investigation of lung cancer has great benefits for the prevention and the treatment of lung cancer.Lung cancer is a highly malignant tumor,which is prone to lead to recurrence and metastasis,and its treatment is still one of the most difficult problems in the medical field.The pathological types of lung cancer include non-small cell lung cancer and small cell lung cancer,and the treatments contain surgery,chemotherapy,radiotherapy and targeted treatment etc.Patients diagnosed with lung cancer usually receive more than one treatment.Surgical resection is one main treatment for early lung cancer,and most patients can achieve good efficacy,however about 30%of the patients will recur or die within 5 years.The prognostic factors of lung cancer include gender,age,pathological types,TNM stage,etc.With the gradual development of the medical level,the treatment of the advanced lung cancer has changed from the original simple radiotherapy and chemotherapy to the combined therapy that contains radiotherapy and chemotherapy,targeted therapy as well as combined surgical treatments.Therefore the prognosis of lung cancer has been more significantly improved than before.According to a large number of conclusions in fundamental researches,the invasive biological behavior of lung cancer is closely related to the drive genes,which can affect the formation,the growth and the metastasis of tumors.At the same time,as the protein products of its drive genes can act on the corresponding targets,and affect the growth and the prognosis of tumors.The change of different genes form different subtypes of lung cancer,so that the sensitivity to different drugs is different.In this situation,small molecular drive gene inhibitor came into being,and has significant impact.Although the patients are all the ones of lung cancer,however the characteristics of every patient are all different,which exists the generality and individuality in their clinical features and treatment effects.For that,the individualized medication and accurate drug treatment are put forward.By applying the detection of human genomics,the cancer cause and the accurate drugs can be sure.Then,at last the patients can be provided the optimal treatment,and achieve the best treatment effect,so far,individualized targeted therapy has been gradually used in the treatment of various cancers,such as lung cancer,colorectal cancer,prostate cancer and breast cancer etc.Along with the progress of social economy level and science and technology level,medical technological level also takes a big step forward.progress,the study on the molecular biology mechanism of lung cancer,as well as all kinds of the drive genes of lung cancer genes.Literatures report that the assay of the positive rate of lung cancer drive gene detection can bachieve more than 50%,every drive genes show the characterists of different populations,which show the particular different drive genes.When the universality and the particularity of the driver genes are known,we can set appropriate treatment protocols for patients as soon as possible,at the same time,we can cure the patients better.The research of the lung cancer drive gene remained in its infancy before the 21st century,and the only KRAS gene was known preliminarily,but no further drugs were available,and at the same time the existence of other genes was not found,but in the fourth year of the 21st century,the EGFR gene was discovered,breakthrough has been made in the treatment of lung cancer at the molecular level.So far,many drive genes have been found,and there are targeted drugs for some of the genes,such as BRAF,ALK,RET,ROS1,Her2,c-MET gene etc.Nowadays only about 35%of lung cancer drive genes are unknown.Since the human whole genome project was completed in 2003,gene sequencing technology has moved into the era of "next-generation sequencing(NGS)",which speeds up the sequencing and reduces the cost of sequencing,and the "individualized"and "accurate" treatment was provided for patients faster and better.At present,the human gene sequencing technology has decoded the human gene sequence,therefore,we do the human geno sequencing for a variety of tumor,its cancer adjacent tissues and normal tissues,and we collect the various clinical datas,we formulate the tumor gene database.On this basis,it is helpful to achieve individualization and accurate treatment for cancer by developing the new targeted drugs to treat the new targets.The expression of lung cancer driver gene varies greatly among different races.For example,the mutation rate of epidermal growth factor receptor(EGFR)gene among Asian population is higher than that among Europeans and Americans.However,the gene mutation rate of KRAS is lower than that of Western population.Therefore,it is greatly significant for the precision and individualized treatment of lung cancer to deeply understand the uniqueness of lung cancer driver genes from different races and the clinical features of various driver genes.Part I Gene Expression and Clinical Characteristics of Molecular Targeted Therapy for Lung Cancer Patients in DaLianObjecive:At present,the incidence of lung cancer ranks first in the global malignant tumor,and its mortality rate is also high.With the discovery of various drive genes of lung cancer,individualized targeted therapy has gradually become an important treatment of lung cancer,but nowadays there is a lack of a large sample of driver genes for Chinese population.In this study,it provides a scientific and theoretical basis for screening the target population of lung cancer molecular targeted therapy by analyzing the multiple drive genes expression and clinical pathological features of lung cancer in Dalian.Methods:We collected the pathological tissues of the patients who were diagnosed with lung cancer from January 2017 to June 2018 in the department of thoracic surgery of the second affiliated hospital of Dalian Medical University,and we improved the patients’ corresponding clinical information of patients,such as gender,age,smoking history,pathological type and the degree of pathological differentiation,and so on.All specimens which were obtained by surgery,lung cancer puncture guided by computed tomography and b-ultrasound,were diagnosed as lung cancer by pathological examination.The high-throughput sequencing platform that is "the next generation-gene sequencing method"was used for detection of mutation genes which includes"Epidermal growth factor receptor(EGFR)","echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase(EML4-ALK)","ROS proto-oncogene 1(ROS1)",Kirsten rat sarcoma viral oncgene(KRAS),RET fusion gene,v-raf homcogene homolog B1(BRAF)and other rare genes expression.During this,the gene mutation rate of the patients was calculated.we concluded the epidemiological characteristics of patients with positive results,and the relationship between mutation genes and clinicopathological features.Results:The mutation rates of EGFR,ALK,BRAF,c-MET,Her2,RET,KRAS and ROS1 are respectively 51.7%,5.405%,3.604%,2.703%,1.802%,2.703%,12.613%and 0.9%.EGFR gene mutation are mainly in exon 19 and 21 exon mutations,the characteristics of mutation population mainly include female,non-smoking,stageⅡ,middle differentiated,abscess subtype and lung adenocarcinoma.It is statistically significant for differences between the groups.The ALK gene,c-MET gene,RET gene and ROS1 were not found to exist statistical differences in clinical features.BRAF gene mutation mainly happens to the lung adenocarcinoma patients whose pathological subtype is the solid cerebral subtype.Her2 gene mutation mainly happens to the lung adenocarcinoma patients whose pathological subtype is papillary subtype.KRAS mutation mainly happens to the lung cancer patients whose age are over 60 years old.ln addition,there are many cases existing two or more gene simultaneous mutations.Cinclusion:EGFR,ALK,BRAF,c-MET,Her2,RET,KRAS and ROS1 genes exist high mutation rates in lung cancer patients,and they own different characteristics of population.So it is greatly significant for the precision and individualized treatment of lung cancer patients,EGFR mutation was associated with gender,smoking history,degrees of differentiation,TNM stages and pathological subtypes.KRAS gene mutation is related with age.In addition,EGFR,BRAF and Her2 gene mutations are closely related with pathological subtypes.No correlation was found between other genes and clinical features.Meanwhile,double mutations between EGFR and c-MET or ALK gene were found in the detection,and the correlation remains to be studied further.Therefore,the whole genes detection is an important basis and necessary means for lung cancer patients with the molecular targeted therapy.Part II Identification of a Novel KIF13A-RET Fusion in Lung Adenocarcinoma by Next-generation SequencingAbstract:RET fusions have been reported in 1-2%of lung adenocarcinomas,and represent an actionable target.Patients whose tumors possess RET fusion are associated with clinical benefit from the treatment with multi-kinase inhibitors such as cabozantinib and vandetanib.Further molecular screening for RET fusions is warranted.Novel KIF13A-RET fusion containing an intact RET kinase domain involving exons 1-18 of KIF13A and exons 12-20 of RET was identified in a lung cancer specimen from an 74-year-old Asian never smoker by next-generation sequencing(NGS)during clinical care.The patient was negative for EGFR,ALK,ROS1 and other putative driver alterations.Fusion analysis is consistent with other described RET fusions and is predicted to result in aberrant constitutive activation caused by dimerization and sensitivity to RET-directed therapies.We describe a novel RET-fusion with molecular characteristics consistent with RET-driven non-small cell lung cancer.Our case expands the spectrum of RET fusion partners and supports broad molecular profiling in non-small cell lung cancer optimizing patient therapeutic options.The new RET fusion has immediate clinical implications for cancer patients.PartⅢ Identification of a Novel BRAF Thr599dup Mutation in Lung AdenocarcinomaAbstract:BRAF mutations are known as oncogenic drivers of non-small cell lung cancer(NSCLC).BRAF inhi-bition has demonstrated anti-tumor activity in patients with BRAF V600E mutant NSCLC.Further molecular screening for novel BRAF thr599dup mutation is warranted.The novel BRAF Thr599dup gene mutation,for which the repeat amino acid-tyrosine is inserted between the 599th amino acid and the 600th amino acid in exon 15 of BRAF,was identified by next-generation sequencing(NGS)during routine clinical care in a lung carcinoma sample from an Asian never-smoker.Other putative driver alterations including EGFR,ALK were not found in that patient.BRAF Thr599dup gene mutation analysis was consistent with BRAF v600E gene mutation.Here we report a novel BRAF gene mutation with molecular characteristics consistent with those in BRAF-driven NSCLC.Our case expands the scope of BRAF gene mutations and provides broader molecular profiling for optimizing therapeutic options for patients with NSCLC.The new BRAF gene mutation has important clinical meaning for cancer patients.