Suitability of Computed Tomography-Guided Biopsy Specimens for Subtyping and Genotyping of Non–Small-Cell Lung Cancer

IntroductionRecent advances in the treatment of NSCLC highlight the importance of distinguishing NSCLC subtypes and genotypes. We aimed to determine whether histological specimens obtained from computed tomography (CT)-guided biopsy are suitable for specific subtyping and epidermal growth factor receptor (EGFR) analyses of NSCLC.Patients and MethodsThe clinicohistological data of 332 consecutive patients undergoing 352 CT-guided biopsies for lung lesions between January 2007 and December 2011 were retrospectively analyzed. Additionally, NSCLC specimens were examined for the suitability of EGFR mutational testing.ResultsOf 209 specimens diagnosed as NSCLC, 197 (94.3%) were specifically subtyped into adenocarcinoma (n = 164; 78.5%), squamous cell carcinoma (n = 27; 12.9%) and other subtypes (n = 6; 2.9%). The rate of NSCLC not otherwise specified (NOS) was 5.7%, and the diagnosis of NSCLC-NOS was significantly associated with the poor differentiation of cancer (adjusted odds ratio, 6.17; 95% confidence interval, 1.62-23.55; P = .008). Of 134 histological tumor specimens submitted for EGFR molecular testing, 132 (98.5%) were suitable for analyses, and 130 of them (98.5%) showed conclusive results, revealing 59.8% (n = 79) with EGFR exon mutation(s). The sensitivity, specificity, and positive and negative predictive values of CT-guided biopsy in patients with malignancy were 92.2%, 100%, 100%, and 74.1%, respectively. Six percent (n = 21) of total lung biopsies led to pneumothorax requiring chest drainage, and no procedure-related fatality was observed.ConclusionSmall tumor specimens obtained with CT-guided needle lung biopsy are suitable for specific subtyping and EGFR analyses of NSCLC, thus providing critical information for personalized therapy.