title: Tumor necrosis as a prognostic factor for stage IA non-small cell lung cancer.
abstract: BACKGROUND
  In stage IA non-small cell lung cancer (NSCLC), lobectomy and mediastinal lymph node dissection is considered the standard treatment. However, 20% to 30% of patients have cancer recurrences. The purpose of this study was to determine the patterns and risk factors for recurrence in patients with stage IA NSCLC.
  
  
  METHODS
  We retrospectively reviewed the medical records of 201 patients who had confirmed stage IA NSCLC by lobectomy and complete lymph node dissection.
  
  
  RESULTS
  There were 131 male patients with a mean age of 60.68±9.26 years. The median follow-up period was 41.4 months. Recurrences were reported in 16 patients. One hundred fourteen and 87 patients were T1a (≤2 cm) and T1b (>2 cm to ≤3 cm), respectively. The pathologic results were as follows: adenocarcinomas and bronchioloalveolar carcinomas (n=134); squamous cell carcinomas (n=57); and other diagnoses (n=10). Tumor necrosis and lymphatic invasion were significant adverse risk factors for recurrence based on univariate analysis. Multivariate analysis showed that tumor necrosis was the only significant risk factor to predict cancer recurrence (hazard ratio, 4.336; p=0.032). The 5-year overall survival was 94.8% for necrosis-negative patients and 86.2% for necrosis-positive patients (p=0.04). The 5-year disease-free survival was 92.1% for necrosis-negative patients and 78.9% for necrosis-positive patients (p=0.016).
  
  
  CONCLUSIONS
  Tumor necrosis was shown to be an adverse risk factor for survival and recurrence in patients with stage IA NSCLC. Thus, close observation and individualized adjuvant therapy might be helpful for patients with stage IA NSCLC with tumor necrosis.
authors.affiliation: Center for Lung Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Republic of Korea.
authors.forename: Seong Yong
authors.initials: SY
authors.lastname: Park
authors.forename: Hyun-Sung
authors.initials: HS
authors.lastname: Lee
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Jang
authors.forename: Geon Kook
authors.initials: GK
authors.lastname: Lee
authors.forename: Kyung Young
authors.initials: KY
authors.lastname: Chung
authors.forename: Jae Ill
authors.initials: JI
authors.lastname: Zo
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000209:etiology; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors