摘要
Objective This study aimed to analyze the relationship between the mutations in epidermal growth factor receptor(EGFR)and anaplastic lymphoma kinase(ALK)and their impact on the prognosis and treatment of lung adenocarcinoma.Methods A total of 158 cases of lung adenocarcinoma reported between January 2007 and January 2014 were retrospectively analyzed.These tumors were resected using radical pneumonectomy and underwent pathology-based diagnosis at our institution(Inner Mongolia People’s Hospital,Hohhot,China).The tissue sections were evaluated using the updated World Health Organization classification of lung adenocarcinomas(2015 version),with each histological component recorded in 5%increments.The histological subtypes were classified,and any surviving cases were followed up.The reverse transcription-polymerase chain reaction(RT-PCR)and direct DNA sequencing were used to evaluate mutations in exons 18,19,20,and 21 in the EGFR gene,and the echinoderm microtubule-associated protein-like 4 gene-ALK variant(EML4-ALK)fusions were detected using sequencing.Results Our cohort included 25 patients with pre-invasive adenocarcinoma,13 patients with lepidic,66 patients with acinar,13 patients with papillary,and 25 patients with solid infiltrative adenocarcinoma with the remaining cases presenting with a variety of pathological subtypes.The prognosis of each histological subtype was different with the 5-year disease-free survival and 5-year overall survival(OS)of pre-invasion adenocarcinoma at 100%;the 5-year OS of lepidic,acinar,and papillary adenocarcinoma patients was only 84.6%,72.7%,and 76.9%,respectively.The 5-year OS of solid and mucinous adenocarcinomas were 32.0%and 36.4%,respectively.EGFR mutation was detected in 69 cases with a mutation rate of 43.7%and majority of these mutations were found in exons 19(50.6%)and 21(37.9%),with women and non-smokers shown to experience a higher mutation rate(P<0.05).However,histological subtype analysis showed that EGFR mutations were primarily found in adenocarcinomas.Most of these mutations were found in lepidic(53.8%)or acinar adenocarcinomas(50.0%),whereas these mutations were rare in both solid(28.0%)and mucinous adenocarcinoma(27.2%).The fusion mutation rate in the EML4-ALK gene was 5.69%,and was most common in young,nonsmoking patients(P<0.05).Conclusion The prognosis of patients in each lung adenocarcinoma subtype is different,and these outcomes are likely related to mutations in the EGFR and EML4-ALK genes.EGFR mutation rates are higher in lepidic and acinar adenocarcinomas,whereas EML4-ALK gene fusion mutations are more common in solid and mucinous adenocarcinoma.EGFR mutations are more common in female and non-smoking patients,whereas EML4-ALK fusions are more common in young,non-smoking patients.
基金
Supported by a grant from the Sciences Foundation of Health Commission of Inner Mongolia Autonomous Region(No.201701008).