Author of

• 16549

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  P1.02 - Poster Session with Presenters Present (ID 454)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Biology/Pathology
  • Presentations: 2
  • Moderators:
  • Coordinates: 12/05/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 16591

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    P1.02-042 - Detection of ALK Protein Expression in Lung Adenocarcinomas, a Consecutive Series of Cases from Northeastern Brazil (ID 5741)

    14:30 - 14:30  |  Author(s): F.R. Tavora
    • Abstract

    Background:
    There have been very few studies on ALK status in lung adenocarcinomas in Latin American population. No prior reports in Northeastern Brazil have been published.
    
    Methods:
    We analyzed ALK protein expression with a specific antibody (D5F3 clone) with the Ventana system in a series of consecutive cases from Northeastern Brazil, a previously untested population, and correlated with histologic subtypes according to the 2015 WHO Classification.
    
    Results:
    A total of 94 patients (55% female, mean age 62 years) were tested, including 51 solid, 29 acinar, 6 lepidic, 6 papillary predominant and 2 sarcomatoid carcinomas with adenocarcinoma components. There were 9 positive cases (9.5%), 5 solid predominant, 3 acinar predominant and 1 lepidic. One of the 3 acinar cases had a mucinous component. The positive cases were more often male (p<0.05) with no significant differences in relation to age, smoking history or histologic subtype. The negative cases showed a 32% EGFR mutation rate. Follow-up will be presented.
    
    Conclusion:
    We will describe a series of consecutive adenocarciomas from a population with unknown ALK status with a higher than expected rates, and correlate with the 2015 WHO Classification of Tumors.
    
    

  • 16593

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    P1.02-044 - EGFR Status in a Previously Untested Population from Northeastern Brazil (ID 5751)

    14:30 - 14:30  |  Author(s): F.R. Tavora
    • Abstract

    Background:
    There is limited Brazilian data on epidermal growth factor receptor (EGFR) gene activating mutations prevalence and their clinicopathologic associations especially in the Northeast, with no previous epidemiological reports. The current study aimed to assess the relationship between EGFR mutations and histologic subtypes according to the 2015 WHO Classification.
    
    Methods:
    We assessed the frequencies of EGFR mutations in consecutive pulmonary adenocarcinomas among a population-based sample in Northeastern Brazil. A sample of 351 patients diagnosed from 2014-2016 was analyzed by direct sequencing (45.5%), real time PCR (34.1%) or next generation sequencing (20.4%).
    
    Results:
    The overall mutation rate was was 30.5%. The ratio of exon 19 deletions to exon 21 L858R mutations was 1.2:1. Three patients had T790M mutations detected after progression in use of targeted therapy. Female sex (P = 0.002), never smoking status (P = 0.002), and nonsolid subtype of ADC (P = 0.001) were associated with EGFR mutations on univariate analyses. Acinar predominant and lepidic predominant tumors had a higher rate of mutation but with no statistical significance when evaluated solely. Papillary component did not show correlation with mutations. Tumor differentiation correlated significantly with their incidence of EGFR mutations, lower in poorly differentiated tumors (p=0.005). Follow-up will be presented.
    
    Conclusion:
    We will describe a series of consecutive adenocarciomas from a population with unknown status with a higher than expected rates (higher than Southern Brazil and similar to other Latin American countries), and correlate with the 2015 WHO classification of tumors.