title: Risk of the preoperative underestimation of tumour size of lung cancer in patients with idiopathic interstitial pneumonias.
abstract: OBJECTIVE
  Sublobar resection of lung cancer (LC) is a valuable procedure in patients with idiopathic interstitial pneumonias (IIPs). Having adequate surgical margins is the key to successful sublobar resection, and evaluation of the precise extent of LC is mandatory. However, tumour extent in IIPs is difficult to evaluate. This study assessed the risk of underestimating tumour size by preoperative computed axial tomography (CAT) scan in LC patients with IIPs.
  
  
  METHODS
  A retrospective study was performed on 1221 patients who underwent surgical resection of primary LC at our institute between 2009 and 2013. Review of CAT findings revealed that 136 (11.1%) patients were complicated with IIPs. The discrepancy between radiological and pathological tumour dimensions was measured and underestimation was defined as 10 mm or more in pathological tumour dimension. The rate and cause of preoperative underestimation were also compared between patients with and without IIPs. Univariate and multivariate analyses were performed using a logistic regression model to predict underestimation of the preoperative tumour size.
  
  
  RESULTS
  Maximum tumour dimension was underestimated in 14 (10.3%) patients with IIPs and 35 (3.2%) patients without IIPs. A multivariable analysis revealed that IIP was the only predictive factor for tumour size underestimation identified in this study (hazard ratio = 3.52, P = 0.017). Underestimation of tumour size in patients with IIPs was mainly due to extension of tumour cells in the honeycomb lung.
  
  
  CONCLUSIONS
  IIPs pose a high risk for underestimating tumour size of LCs in preoperative measurements. Thus, tumour extent should be assessed carefully in order to maintain adequate surgical margins.
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Fukui
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Takamochi
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsunaga
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Shiaki
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of Respiratory Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Ando
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Arakawa
authors.affiliation: Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Uekusa
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan kjsuzuki@juntendo.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000150:complications*; D008175:Lung Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Idiopathic interstitial pneumonia; Lung cancer; Pulmonary fibrosis; Tumour size; Underestimation