title: Volume-based growth tumor kinetics as a prognostic biomarker for patients with EGFR mutant lung adenocarcinoma undergoing EGFR tyrosine kinase inhibitor therapy: a case control study.
abstract: BACKGROUND
  We aim to determine whether volumetric assessment has the potential to serve as a prognostic biomarker, and to assess the relationship between longitudinal tumor data during treatment and prognosis in lung adenocarcinoma patients with sensitizing EGFR mutations treated with EGFR tyrosine kinase inhibitors (TKI).
  
  
  METHODS
  We retrospectively assessed patients with EGFR-mutant stage IV lung adenocarcinoma who were treated with EGFR TKIs until disease progression. CT studies of 106 patients were quantitatively analyzed in terms of tumor size and volume by comparing baseline and follow-up CT scans obtained at every two treatment cycles. Tumor response was quantified using longitudinal measurements, and tumor growth kinetics was determined. Correlation with early surrogate parameters for tumor response evaluation such as change in size, volume, and response rate was performed. The Cox-proportional hazard model and Log-rank test were used to predict overall survival (OS).
  
  
  RESULTS
  Responders based on the percent change in volume after four cycles of TKI therapy had a higher OS than non-responders (P = 0.035). The percent of volume and size changes after four cycles of TKI therapy were significantly correlated with TTP (P < 0.001).
  
  
  CONCLUSIONS
  Volume measurements and corresponding rates of growth appear to be helpful adjuncts for predicting survival in patients undergoing EGFR-TKI therapy.
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea. hoyunlee96@gmail.com.
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Division of Hemato-Oncology of the Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, South Korea.
authors.forename: Myung-Ju
authors.initials: MJ
authors.lastname: Ahn
authors.affiliation: Division of Hemato-Oncology of the Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, South Korea.
authors.forename: Keunchil
authors.initials: K
authors.lastname: Park
authors.affiliation: Division of Hemato-Oncology of the Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, South Korea.
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.affiliation: Division of Hemato-Oncology of the Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, South Korea.
authors.forename: Jong-Mu
authors.initials: JM
authors.lastname: Sun
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor; D016022:Case-Control Studies; D003287:Contrast Media; D018450:Disease Progression; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics; D000069347:Erlotinib Hydrochloride / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009367:Neoplasm Staging; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011799:Quinazolines / Q000627:therapeutic use*; D012074:Remission Induction; D012189:Retrospective Studies; D015996:Survival Rate; D036542:Tomography, Spiral Computed / Q000379:methods; D047368:Tumor Burden / Q000187:drug effects; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D003287:Contrast Media; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors; D000077156:Gefitinib
keywords: Biomarkers; Growth kinetics; Prognosis; Quantitative analysis; Tumor volume