title: Serum cytokeratin 19 fragment, CK19-2G2, as a newly identified biomarker for lung cancer.
abstract: BACKGROUND
  CK19-2G2, a new fragment of cytokeratin 19, is a potential tumor marker for diagnosing lung cancer. The preoperative level of serum CK19-2G2 has been demonstrated to be associated with tumor metastasis and survival of breast cancer patients. This study investigated the postoperative dynamic changes in serum CK19-2G2 levels and its clinical significance in lung cancer patients.
  
  
  METHODS
  Preoperative serum CK19-2G2 levels were measured in 630 lung cancer patients and were compared with individuals with benign pulmonary diseases (n = 134) and healthy volunteers (n = 263). In 352 cases, the patients underwent surgery. In these patients, in addition to preoperative assays, serum CK19-2G2 was also monitored at 1 week and 1 month after the operation.
  
  
  RESULTS
  The preoperative baseline levels of serum CK19-2G2 was significantly higher in lung cancer patients than patients with benign diseases and healthy controls (P<0.001). The postoperative levels of CK19-2G2 declined significantly within 1 week after tumor resection. Hereafter, a further decrease was observed in the patients who underwent palliative operations, while for the patients in the radical resection group, their CK19-2G2 levels stabilized.
  
  
  CONCLUSIONS
  CK19-2G2 may be a candidate marker for diagnosing and monitoring a patient's response to lung cancer treatment. In addition, CK19-2G2 may be an indicator for micrometastases in lung cancer patients.
authors.affiliation: Clinical Laboratory, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Thoracic Surgery, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Lv
authors.affiliation: Clinical Laboratory, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Clinical Laboratory, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Zongyong
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Clinical Laboratory, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Qi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood* / Q000737:chemistry; D005260:Female; D006801:Humans; D053539:Keratin-19 / Q000097:blood* / Q000737:chemistry; D008175:Lung Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D053539:Keratin-19; D010446:Peptide Fragments; C102012:antigen CYFRA21.1