Author of

• 13580

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  P1.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 233)

  • Event: WCLC 2015
  • Type: Poster
  • Track: Biology, Pathology, and Molecular Testing
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/07/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)

  • 13583

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    P1.04-003 - Metastatic Site-Specific Variation of KRAS Status in Lung Adenocarcinoma (ID 2704)

    09:30 - 09:30  |  Author(s): G. Badalian-Very
    • Abstract
    • Slides

    Background:
    While KRAS mutation is a negative predictive marker for EGFR tyrosine kinase inhibitor therapy, there is limited data available regarding the influence of KRAS mutation on the organ specificity of lung adenocarcinoma metastases.
    
    Methods:
    In our retrospective, single center study, 820 lung adenocarcinoma patients with KRAS mutation analyses were included. At the time of diagnosis, 462 patients had metastatic disease. These cases were analyzed for the potential association between KRAS status and metastatic site and clinical outcome. Patients with known EGFR mutations were excluded from the study.
    
    Results:
    534 (65.3%) KRAS wild-type and 284 (34.7%) KRAS-mutant cases were identified. There was no difference in the KRAS mutation prevalence between the metastatic (35.7%) and non-metastatic cases (33.4%). The most frequent metastatic sites included bone (29%), contralateral lung (24.8%), ipsilateral lung (19.7%), brain (17.3%), adrenal gland (15.6%), pleura (12.8%) and liver (11.7%). Patients with multiple metastases tended to have inferior median overall survival (OS) compared to those with single-organ metastasis (6.3 vs. 8.2 months, respectively; p=0.09) and, moreover, showed a slight but non-significant increase in the prevalence of KRAS mutations (38.5%, p=0.35). Importantly, patients with brain (35.8%), bone (33.1%) or adrenal gland (35.2%) metastases demonstrated similar KRAS mutation frequencies. However, both ipsilateral and contralateral intrapulmonary metastatic cases demonstrated increased KRAS mutation frequency when compared to those with extrapulmonary metastases (42.2% and 42.5%, p=0.014). In contrast, pleural dissemination and liver metastasis were associated with decreased KRAS mutation prevalence (25.4% and 24.1%, respectively; p=0.007). We found no difference in the median OS between KRAS-mutant and WT cases in any metastatic site-specific analysis.
    
    Conclusion:
    Lung adenocarcinoma patients with KRAS-mutant tumors more often present with intrapulmonary metastases. KRAS mutation prevalence, however, lacks to provide prognostic information. Further studies are required to determine if KRAS status can be used to risk stratify patients for the onset of pulmonary metastasis.
    
    

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