Author of

• 11917

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  P2.21 - Poster Session 2 - Diagnosis and Staging (ID 170)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Prevention & Epidemiology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11920

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    P2.21-003 - The relationship between the type of bone metastasis and EGFR gene mutation in non-small cell lung cancer (ID 2177)

    09:30 - 09:30  |  Author(s): K. Akanabe
    • Abstract

    Background
    The bone is the most common distant site of metastasis in non-small cell lung cancer (NSCLC), and patients with bone metastasis have a markedly poor prognosis. There are three types of bone metastasis; such as osteolytic type, osteoblastic type, and mixed type. Assessment of bone metastatic type may be important as a part of therapeutic strategy because it has been noted that osteoblastic tumors would have lead to both a better prognosis and activating epidermal growth factor receptor (EGFR) mutation presence. The aim of this study was to examine the relationship between the type of bone metastasis and clinical characteristics including EGFR gene mutation status in NSCLC patients.

    Methods
    We reviewed the records of 85 unresectable or postoperative recurrent NSCLC patients with at least one site of bone metastasis. The type of bone metastasis was classified by two radiologists reviewing the radiological examination as osteolytic type (OL), osteoblastic type (OB), and mixed-type from the CT findings.

    Results
    Median follow-up time for survivors was 25.4 months. There were 53 (62%) patients with unresectable NSCLC and 32 (38%) patients with postoperative recurrent disease. The number of patients with adenocarcinoma is 75 (87%). The bone metastasis type was OL group in 39 (46%) patients, OB group in 37 (43%) patients, and mixed type in 9 (11%) patients. Survival analysis incorporating mixed type bone metastasis into OB group revealed median survival time of 20.3 months and 30.9 months for OL and OB group, respectively. The difference was not significant (p=0.314), but OB group seems to have better prognosis than OL group. The prevalence of activating EGFR gene mutation was marginally significance in OB group (58%) than in OL group (36%) (p = 0.052). There are no significant relationship between the type of bone metastasis, and sex and smoking history.

    Conclusion
    This study shows that evaluating the type of bone metastasis by CT image enable prediction of EGFR gene mutation status and prognosis in NSCLC patients with bone metastases separately from sex, smoking habit, and race. The presence of osteoblastic metastases or the evolution to metastases should always be noted since it might represent an important predictive factor of response to EGFR-TKI treatment.