[352] Lung Sarcomatoid Carcinoma (SC): EGFR Mutation Analysis on Fine Needle Aspiration Biopsy (FNAB) with Clinicopathologycal Study (23 Cases)

Carme Dinares, Javier Hernandez-Losa, Carmela Iglesias, Inessa Koptseva, Margarita Alberola, M Angeles Montero, Anna Solsona, Santiago Ramon y Cajal, Natalia Tallada. Vall d'Hebron University Hospital, Barcelona, Spain

Background: SC is a rare group of non small-cell lung carcinomas (NSCLC) with sarcomatous differentiation. Five subgroups are recognized (pleomorphic, spindle cell, giant cell, carcinosarcoma and pulmonary blastoma). Tobacco is the major etiologic factor implicated. Asbestos exposure may also be related. Prognosis is worse than others NSCLC. Clinical outcome is stage dependent with poor response to conventional treatment.
Design: The aim is to determine the EGFR mutations on cytology samples from SC and correlate the results with clinical stage, treatment and outcome. 23 cytology samples diagnosed as SC were collected from our files (2001 to 2011): 2 sputum and 21 FNAB (16 lung primary lesions and 5 metastasis -2 bones, 1 chest wall, 1 adenopathy and 1 skin-). Cytologyc diagnosis was confirmed by histology (9 surgical specimens, 10 cell block and 1 autopsy). DNA was extracted and EGFR mutation was detected by polymerase chain reaction followed by restriction enzyme digestion and sequencing of exon 19, 20 and 21. Follow up, treatment and outcome were evaluated from clinical reports.
Results: 20 cases were men and 3 women. The median age was 62y (39-96). 17 were smokers, 2 non-smokers (1 exposed to asbestos) and 4 unknown. In 85 % the lesion was located in the right pulmonary lobe. The up/down lobe ratio was 3/1. Average tumor size was 5.3cm (1-12.4). The clinical stage at the diagnosis was IV (47.8%), IIIB (4.34%), IIIA (17.39%), IIB (8.69%), IB (4.34%), unknown (17.39%). Stages IB, IIB and IIIA were treated with surgery, chemotherapy (CT) and some with combined radiotherapy (RT). Stages IIIB and IV were treated only with CT and RT. 14 patients were dead (stage IV in 57.1%) with a mean survival of 13.7 months, 7 are alive with a mean survival of 22.2 months and 2 with unknown outcome. The EGFR results were: 1 not available, 20 wild-type and 2 cases mutated on exon 21 (L858R) which were in stage IV. The treatment they received didn't change the outcome. They die after short survival.
Conclusions: Our results are similar as those from other series. SC has a poor prognosis. The diagnosis is made in advanced stage. The tumor is more frequent in men and in the upper lobes. EGFR mutation in our series is 9.1%, all of them in stage IV. Further studies are needed to conclude if EGFR inhibitors could improve the survival rates in patients with EGFR mutation.
Category: Cytopathology

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 76, Wednesday Afternoon

 

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