[Diagnosis of lung biopsy employing the 2015 WHO criteria and detection of related oncogenic driver mutations].

ABSTRACT

Objective: The diagnostic criteria of lung biopsy specimens by 2015 WHO lung tumor classification were used to evaluate lung biopsy specimens along with detection of genetic alterations of major tumor driving genes including epidermal growth factor receptor (EGFR). Methods: The clinical data, histological slides, immunohistochemical stains and special stains of 806 lung biopsy specimens at Beijing Hospital from July 2015 to July 2018 were retrospectively analyzed. Diagnosis of lung cancer was reclassified according to the 2015 WHO lung tumor classification and related gene mutation data were analyzed. Results: During a three-year period, the total number of lung cancer diagnosis was 483 cases, including 221 female and 262 male patients with age ranging from 37 to 85 years (median age of 65 years). There were 40 cases(8.28%) of small cell carcinoma,11 cases (2.28%) of large cell neuroendocrine carcinoma, 3 cases (0.62%) of combined neuroendocrine carcinoma, 2 cases(0.41%) of atypical carcinoid, 208 cases (43.06%) of adenocarcinoma, 92 cases(19.05%) of non-small cell carcinoma, favor adenocarcinoma, 66 cases (13.66%) of squamous cell carcinoma, 42 cases(8.70%) of non-small cell carcinoma, favor squamous cell carcinoma, 16 cases(3.31%) of non-small cell carcinoma, not otherwise specified, and 3 cases (0.62%) of non-small cell carcinoma, possible adenosquamous carcinoma. Among 202 cases tested, 107 cases (52.97%) showed EGFR mutations, including 86 of 133 cases (64.66%) of adenocarcinoma and 18 of 52 cases (34.62%) of non-small cell carcinoma, favor adenocarcinoma. Twenty two cases were found to have T790M mutation among 27 patients after EGFR TKI targeted drug therapy. Immunohistochemical staining of ALK (D5F3) was positive in 3 of 354 cases of non-small cell lung cancer, confirmed by EML4-ALK fusion gene fluorescence PCR. ROS1 gene fusion was found in 1 of 38 cases. Splicing mutations in exon 14 of MET gene were seen in one case of non-small cell carcinoma with spindle cell differentiation. Conclusion: The new diagnostic criteria by the 2015 WHO lung tumor classification is better suited for diagnosing lung biopsy specimens and providing accurate treatment guidance and improving the patient outcome.