title: Risk factors of recurrence for resected T1aN0M0 invasive lung adenocarcinoma: a clinicopathologic study of 177 patients.
abstract: BACKGROUND
  This study aimed at identifying risk factors of recurrence for completely resected pathologic T1aN0M0 lung adenocarcinomas.
  
  
  METHODS
  We reviewed the records of 177 T1aN0M0 invasive adenocarcinoma patients, and re-classified achieved surgical specimens according to the new International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) lung adenocarcinoma classification. Impact on recurrence-free survival (RFS) for age, gender, smoking history, lymphovascular invasion (LVI) and new classification was analyzed by log-rank test and Cox regression. Two existing prognostic grouping schemes of new classification were compared, and subsequently, the correlation of high-grade group in the better prognostic grouping model with clinical data was investigated statistically.
  
  
  RESULTS
  The 5-year recurrence-free rate was 83.7%. The LVI and new adenocarcinoma classification were significantly associated with 5-year RFS (P = 0.012; P = 0.022, respectively). The designation of papillary predominant subtype in the low-grade group, along with lepidic- and acinar predominant subtype had more prognostic significance than the model of combining papillary-, solid- and micropapillary predominant subtypes as the high-grade group (P = 0.005 versus P = 0.181). This high-grade group has increased risk of recurrence in a multivariate Cox regression (adjusted HR 2.815, 95% CI: 1.239 to 6.397, P = 0.013), and is associated significantly more with male gender (adjusted OR 2.214, 95% CI: 1.050 to 4.668, P = 0.037), and, with borderline significance, the presence of LVI (adjusted OR 2.091, 95% CI: 0.938 to 4.662, P = 0.071).
  
  
  CONCLUSIONS
  Our results showed that the solid- and micropapillary predominant subtype of IASLC/ATS/ERS classification remains the only risk factor for post-operative recurrence of T1aN0M0 adenocarcinomas, suggesting that they can be indicators of aggressive tumor behaviors.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Kezhong
authors.initials: K
authors.lastname: Chen
authors.forename: Yida
authors.initials: Y
authors.lastname: Liao
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.forename: Kunkun
authors.initials: K
authors.lastname: Sun
authors.forename: Dongmei
authors.initials: D
authors.lastname: Bao
authors.affiliation: Department of Thoracic Surgery, Peking University People's Hospital, 11 Xizhimen Nan Ave, Beijing 100044, China. jwangmd@yahoo.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000150:complications* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D002291:Carcinoma, Papillary / Q000150:complications* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate