2012 June - Treatment Outcomes in Elderly with Advanced-stage Non-Small Cell Lung Cancer
Dr. Terence Chi-Chun TAM; Department of Medicine, Queen Mary Hospital
Introduction - In Hong Kong, over 4000 new cases of lung cancer are diagnosed every year. The median age at diagnosis is 71 for men and 73 for women. Existing therapeutic clinical trials, however, seldom focused on elderly lung cancer subjects. Although the identification of epidermal growth factor receptor (EGFR) gene mutations could predict clinical efficacy of tyrosine kinase inhibitor (TKI), these molecular testing for predictive biomarkers are not always possible or available due to tissue availability or financial constraints. Moreover, no reliable treatment outcome predictors could be identified for EGFR wild-type patients. The overall therapeutic decision remains a clinical one for a significant proportion of elderly patients with advanced stage non-small cell lung cancer (NSCLC). The predictive performance of individual parameters of age, performance status (PS) and comorbidities is not clearly defined in this subgroup.
Objectives – The aims of this study were to compare the outcome of different drug treatment modalities in terms of progression-free survival (PFS), overall survival (OS) and adverse effect profile for elderly with advanced-stage NSCLC, and to identify any clinical parameter that could predict treatment outcomes.
Methods - Clinical records of patients aged 70 years or above with Stage III or IV NSCLC (ICD 9 code – 162.x), who have received either chemotherapy or tyrosine kinase inhibitor (EGFR-TKI) in the Department of Medicine, Queen Mary Hospital from 2003 to 2009, were reviewed. Cox proportional hazard model was used to examine factors associated with PFS and OS. The frequencies of treatment-related complications were also reviewed. A group of gender- and histology-matched subjects aged below 70 were identified as controls.
Results – 56 elderly patients (age ≥ 70) were included. The median age at diagnosis was 73 years (age range: 70-83 years). The proportion of NSCLC, adenocarcinoma (AD) and squamous cell carcinoma (SCC) were 21.4%, 48.2% and 16.1% respectively. 60.7% of patients received only one line of treatment (i.e. either chemotherapy or EGFR-TKI). Median PFS was 10 months (IQR 5 to 15 months) and the OS was 19 months (IQR 11 to 31 months). Among different clinical parameters tested, baseline performance status (PS) was the only predictor of improved PFS (p = 0.042) and OS (p = 0.002). Age was not a significant prognostic factor, and there was no difference in survival (in both PFS and OS) between the upfront chemotherapy group and the TKI group. Tolerability (i.e. no complications) was similar among chemotherapy and TKI usage. Sub-analysis showed that there was no significant difference (p = 0.667) in OS between the elderly cohort and their younger counterparts.
Conclusion – In elderly subjects with advanced stage NSCLC without known EGFR mutation status, use of EGFR-TKI and chemotherapy resulted in comparable survival benefits and rates of treatment-related adverse effects. Advanced age (>70 years) was not predictive of worse treatment outcome in advanced stage NSCLC patients. The baseline performance status of the patient should be taken into consideration in the therapeutic decision in elderly subjects with NSCLC.
