PURPOSE: The purpose of this study is to report the molecular outcomes and characteristics of patients undergoing endobronchial ultrasound (EBUS)-guided fine needle aspiration as part of evaluation of mediastinal adenopathy.
METHODS: This is a single-institution, retrospective review of all EBUS patients who underwent KRAS or EGFR testing between 2009 and 2010, identified by billing and equipment codes. Descriptive statistics were used to characterize this population.
RESULTS: We identified 23 patients who underwent genetic testing for EGFR, KRAS, or both. Five of these 23 (21.7%) had a previous malignancy: 2 colon cancers and one each of bladder cancer, prostate cancer, and adenocarcinoma of the lung. The average time since previous cancer diagnosis was 69 months. Of the 23 patients, 21 (91.3%) smoked with an average pack years of 42.8. Of the 21 patients who underwent EGFR testing, 2 (9.5%) were positive. Both were diagnosed with stage IV adenocarcinoma of the lung and treated with erlotinib. One, who was a lifetime nonsmoker, is alive and well after 18 months. The other patient, who had a 45 pack year smoking history, died within two months of diagnosis. Of the 17 patients who underwent KRAS testing, 2 (11.8%) were positive. One was diagnosed with recurrent adenocarcinoma of lung, refused treatment, and died within one month. The other was diagnosed with stage IV adenocarcinoma of the lung, received chemotherapy, and is alive and well two years later. Both were previous smokers of greater than 45 pack years.
CONCLUSIONS: EBUS-guided fine needle aspirates provide adequate tissue to derive genetic testing. EGFR mutations were discovered at an expected rate, while KRAS mutations were slightly lower than expected. Results from EBUS-derived genetic testing influenced chemotherapy decisions in three of the four patients.
CLINICAL IMPLICATIONS: In patients with lung cancer that are diagnosed or staged by EBUS, KRAS and EGFR genetic testing should be considered as results may guide chemotherapeutic options.
DISCLOSURE: The following authors have nothing to disclose: B. Payne Stanifer, Konstantin Dragnev, Peter Delong, Lisa Tilluckdharry, James Rigas, Anne McGowan, Piroska Kopar, William Nugent, Cherie Erkmen
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