title: Genetic characterization drives personalized therapy for early-stage non-small-cell lung cancer (NSCLC) patients and survivors with metachronous second primary tumor (MST): A case report.
abstract: BACKGROUND
  The pathogenesis and progression of lung cancer is a complicated process in which many genes take part. But molecular gene testing is typically only performed in advanced-stage non-squamous non-small-cell lung cancer (NSCLC). The value of tyrosine kinase inhibitors (TKI) administration is not widely recognized with respect to early-stage NSCLC.
  
  
  METHODS
  Here, we present a case of a man, heavy smoker who initially presented with stage IA lung adenocarcinoma (LADC). Three years after a lung lobectomy, he was diagnosed with advanced lung squamous cell carcinoma (SCC), according to laboratory, imaging, and pathological examinations.
  
  
  METHODS
  The case initially had an early-stage LADC with an L858R epidermal growth factor receptor (EGFR) mutation. A subsequent advanced SCC bearing EGFR L858R/T790M mutations occurred 3 years after surgery.
  
  
  METHODS
  The comprehensive therapy we utilized, including surgical resection for the early-stage lesion and GP chemotherapy and local radiotherapy as the first line therapy along with gefitinib maintenance treatment for the advanced metachronous second primary tumors (MST).
  
  
  RESULTS
  The synthetical therapy, have resulted in our patient with remaining alive and progression free for 4.5 years.
  
  
  CONCLUSIONS
  This case suggests that changes in molecular pathology should be monitored closely throughout cancer progression to guide personalized therapy and improve prognosis. We further review administration of TKI to early-stage NSCLC and to the metachronous second primary tumors (MST) in survivors.
authors.affiliation: Department of Oncology, Weifang Medical University, Weifang Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Science Department of Oncology, Shandong University Department of Radiation Oncology, Jinan Central Hospital, Jinan, China.
authors.forename: Xingchen
authors.initials: X
authors.lastname: Ding
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.forename: Xijun
authors.initials: X
authors.lastname: Liu
authors.forename: Xindong
authors.initials: X
authors.lastname: Sun
authors.forename: Jinming
authors.initials: J
authors.lastname: Yu
authors.forename: Xue
authors.initials: X
authors.lastname: Meng
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000628:therapy; D018773:Genes, erbB-1; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary