Author of

• 11745

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  P2.11 - Poster Session 2 - NSCLC Novel Therapies (ID 209)

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

  • 11752

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    P2.11-007 - Relevance Between CEA Level and EGFR Mutation, Efficacy Of EGFR-TKI In Patients With Lung Adenocarcinoma (ID 910)

    09:30 - 09:30  |  Author(s): W.Y. Zhang
    • Abstract

    Background
    EGFR-TKI has been widely used in the treatment of advanced NSCLC with positive EGFR mutation. However, tumor tissues may not always be available in patients with inoperable NSCLC. Although peripheral blood can be used to test the mutations, but the sensitivity are not satisfactory.Studies have found that the CEA level are higher in patients with positive EGFR mutation. And it also have been reported that the variation of CEA level before and after EGFR-TKI therapy was closely related with therapy efficacy. So if we use high CEA level to predict the EGFR mutation, could we get a higher sensitivity than use peripheral blood to test the mutation? Are the variation types of CEA related with the efficacy of EGFR-TKI? To solve these questions, we designed this study and hope to find a marker to predict EGFR mutation and efficacy of EGFR-TKI.

    Methods
    70 cases of newly diagnosed non-smoking adenocarcinoma of NSCLC were included in the study. We detected their EGFR mutation status, record their clinical characteristics and test CEA level. The patients with positive EGFR mutation receive EGFR-TKI treatment. The EGFR mutation status of these patients’ blood was analyzed by HRM and ARMS. Then we tested their CEA level on the third, seventh, fifteenth and thirtieth day after EGFR-TKI treatment respectively. We evaluated the efficacy on the first month and confirm it on the second month.

    Results
    44/70 cases were found with EGFR gene mutations.Including 25 cases of exon19,18 cases of L858R mutation and 1 case of exon20 mutation. EGFR mutation rate of serum CEA high-level group was significantly higher than low-level group (EGFR gene mutation rate of patients with serum CEA level <5ng/ml vs. ≥ 5ng/ml was 40.9% vs. 70.8%, p=0.017). Multivariate analysis showed that CEA high-level is independently associated with EGFR gene mutation rate. (p=0.020,OR=3.508, 95%CI：1.223-10.059).The sensitivity, positive predictive value and accuracy of high CEA level to predict EGFR mutation is 79.1%,70.8% and 67.1%.The sensitivity of HRM and ARMS is 13.9% and 51.2% respectively. 43 patients received EGFR-TKI treatment, 2 patients quit the study due to severe adverse reaction. We evaluate the efficacy and follow up their PFS.The total ORR is 41.9%, DCR is 74.4%.We divided the patients through the variation types of CEA into three groups: descending type, first increased then decreased type and ascending type. Analysis the relevance between clinical characteristics and efficacy of EGFR-TKI shows that the variation types of CEA is the only influencing factor (P=0.001). Univariate analysis of NSCLC patients who received EGFR-TKI first-line treatment shows that patients with descending type have longer PFS (P=0.001, HR 6.981, 95%CI: 2.534-19.237). Multivariate Cox proportional hazards model analyses of various factors affecting PFS shows the same result (P=0.001, HR 9.82, 95%CI: 3.322-26.031).

    Conclusion
    Patients with high CEA levels have a higher rate of EGFR mutations in NSCLC. Using high CEA level for predicting EGFR mutation is more sensitive than using peripheral blood to test EGFR mutation; the variation types of CEA could help us to predict the efficacy of EGFR-TKI for a short time (one month).