SESSION TYPE: Lung Cancer Posters I
PRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PM
PURPOSE: Epidermal growth factor receptor(EGFR) mutation analysis is necessary and important in clinical practice. But sometimes advanced lung cancer is diagnosed by cytology or inadequate specimens for DNA extractions. This study was aimed to investigate the association of EGFR mutations with clinicopathologic features in small biopsy specimens.
METHODS: The medical records of two hundred fifty-nine (257 biopsies and 2 resections) lung adenocarcinoma patients were reviewed. All the specimens of these patients were investigated for EGFR mutations (Exon 18-21) by direct sequencing method. Among these specimens, one hundred twenty-seven were classified according to International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification (IASLC/ATS/ERS classification)
RESULTS: EGFR mutations were present in 37.1% (96 of 259) of lung adenocarcinoma patients. The majority of them was exon 19 deletions (58 of 101, 60.4%), and five patients had mutations in the multiple sites. As expected, the incidence of EGFR mutations was the highest in never-smoked women patients (50 of 94, 53.2%). On the other hand, EGFR mutations in ever-smoked men patients (36 of 142, 25.4%) were found relatively frequent. On the basis of IASLC/ATS/ERS classification, acinar pattern accounted for 43.3%, followed by solid (24.4%), lepidic(10.2%) and papillary(7.1%). EGFR mutations were more frequently observed with acinar and lepidic components, conversely infrequently with solid and mucinous components. Immunohistochemical(IHC) stain of TTF-1 was also related with the frequency of EGFR mutations.
CONCLUSIONS: We can ascertain that incidence of EGFR mutations is associated with gender and smoking history in small biopsy specimens. Acinar and lepidic subtype of histology, even if the histology comfirmed by only small biopsies, can predict the high frequency of EGFR mutations.
CLINICAL IMPLICATIONS: The small biopsy specimens from advanced lung cancer patients, even if he is heavy smoker, should undergo EGFR mutation test because its incidence is relatively high in Korea. When the specimens are not enough for DNA extractions and re-biopsy is incapable, the clinicopathologic features can predict the EGFR mutation status carefully but it cannot replacement the mutation analysis.
DISCLOSURE: The following authors have nothing to disclose: Hyun Jung Kim, Kyeong-Cheol Shin
No Product/Research Disclosure InformationRegional Center for Respiratory Disease, Yeungnam University Medical Center, Daegu, Republic of Korea