Author of

• 11543

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  P2.06 - Poster Session 2 - Prognostic and Predictive Biomarkers (ID 165)

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

  • 11592

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    P2.06-049 - TTF1 negative status is a negative predictor of benefit to Erlotinib (E) in metastatic Non Small Cell Lung Cancer (NSCLC) (ID 3382)

    09:30 - 09:30  |  Author(s): E. Porphyrides
    • Abstract

    Background
    Erlotinib (E) is currently indicated as first line therapy in patients with EGFR mutations, and as second and third line treatment for patients with advanced metastatic NSCLC. In Cyprus comprehensive EGFR testing started in January 2011. In this study we reviewed all the patients that received E between 2007-2010, without having undergone EGFR mutation testing, looking at predictive factors of response to E. In view of evidence suggesting that EGFR mutations are found in predominantly TTF1 +ve tumours, TTF1 status as well as clinical factors (i.e. adenocarcinoma histology, female sex and non smoking status) were assessed as potential predictive factors of response to E.

    Methods
    100 consecutive patients are included. 3 patients received this as 1[st] line, 49 patients as 2[nd] line and 48 patients as 3rd line and beyond. Previous treatments included gemcitabine platinum doublet as first line, and either pemetrexed or docetaxel as 2[nd] line therapy. Patients had regular Chest x-rays (every 2-3 cycles) and CT scans (every 3-4 cycles) and were assessed clinically on a monthly basis. Survival outcomes for both progression free survival (PFS) and overall survival (OS) were calculated with Kaplan Meier. Subset analyses using smoking status, sex, histology type and TTF1 and finally Cox regression was undertaken.

    Results
    40 female and 60 male were treated with E. Median age is 66 years (range 32-79). 45 patients were WHO performance status (PS) 0-1, 47 PS 2-3. For 8 patients PS was not recorded. Median progression-free survival (PFS) for all patients was 95 days (95% CI 68-118). Median overall survival (OS) from starting E was 144 days (95% CI 103-185). Toxicity was predominantly grade 0-2. Ten (10) patients had a partial response and 34 patients had stable disease. Subset analyses were undertaken based on smoking status, sex, histology type and TTF1. Univariate analysis for PFS using KM plots showed a statistically significant difference for sex, smoking and TTF1. On Cox regression only gender and TTF1 were statistically significant (0.007 and 0.006). There was a striking difference in median OS between patients with TTF1-ve tumours (33 days) and TTF1 +ve tumours (149 days). See table underneath.

    	Median PFS (days)	95% CI (days)	Log Rank	Median OS (days)	95% CI (days)	Log Rank
    All patients	95	68-118	-------	144	103-185	-------
    Female	165	46-284	0.0137	236	45-427	0.1470
    Male	80	40-120		104	60-148
    < 10 Pack Yrs	203	149-257	0.0009	291	193-389	0.0034
    > 10 Pack Yrs	54	15-93		84	53-115
    TTF1 – ve	28	11-45	0.0002	33	28-38	0.0001
    TTF1 +ve	109	34-184		149	35-263

    Conclusion
    TTF1 is a better predictor of benefit to E than histology, sex and smoking status. The very low median PFS and OS for patients with TTF1 –ve tumours would suggest that such patients derive no benefit from E, hence TTF1-ve status acts as a negative predictor of benefit to E.