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M.P. Macedo
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P2.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 234)
- Event: WCLC 2015
- Type: Poster
- Track: Biology, Pathology, and Molecular Testing
- Presentations: 1
- Moderators:
- Coordinates: 9/08/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P2.04-033 - Patterns of <em>EGFR</em> Mutations in a Cohort of 395 Patients from a Single Institution in Brazil (ID 2954)
09:30 - 09:30 | Author(s): M.P. Macedo
- Abstract
Background:
Lung cancer is among the most common malignancies in Brazil. Nevertheless, so far, there are no official data on EGFR mutation frequency in the country, the test is not routinely offered in the public system and there seems to exist great disparities in patient access to EGFR testing across regions. In this study we describe the frequency and patterns of EGFR mutations from a single brazilian institution.
Methods:
DNA samples were obtained either by slide scraping or by laser microdissection of tumoral cells from paraffin embedded tissue blocks. Exons 18, 19, 20 and 21 of EGFR gene were tested for mutation by direct sequencing or by pyrosequencing using standard protocols. We used chi-square statistics, or Fisher’s exact test when appropriate, to compare proportions among groups.
Results:
From Aug/2010 to Jun/2014, 395 patients were tested for EGFR mutation at AC Camargo Cancer Center, Sao Paulo. Among tested patients, median age was 64y, 51% were female, 91% had adenocarcinoma, 27% were smokers/former smokers with median 12 pack year smoking history. The presence of EGFR mutations was associated with non-smoking status (p=0.023). Twenty six percent of patients (105/395) had EGFR mutations, 28.6% (30/105) of them were L858R, 42.9% (45/105) were exon 19 deletions and 28.6% (30/105) were composed of rare or complex mutations. Among patients with rare mutations, 56.6% (17/30) had more than one mutation detected. Rare/complex mutations were more frequently associated with non-adenocarcinoma histology (p=0.014), smoking history (p=0.03) and smoking intensity (p=0.02).
Conclusion:
In this cohort, the mutation frequency was higher than that reported in other western countries series. The high proportion of rare and complex mutations is also worthnoting and was more frequently seen in heavy smokers with non-adenocarcinoma histology.
