P2.13-17 Non-Small Lung Cancer in the Very Young: More EGFR/ALK Mutation Rate Than the Elder.

Abstract

Lung cancer was the leading cause of cancer in worldwise1. Although it remains a disease of older patients, there is a subset of patients who are diagnosed at younger age, such as blow 40 year old. Several studies had shown that the younger group had more females, more non-smokers, more advanced stages of disease, and better survive rate. However, most of these studies didn’t include tumor EGFR/ALK mutation data, especially for the younger group. We retrospectively studied the clinical difference between the younger and the older in patients, including pathologic type, treatment characteristics, and EGFR/ALK mutation status. We retrospective reviewed data of NSCLC patients diagnosed during Jun. 2007 to Dec. 2014, and whose age was less than 90 year-old. at Taipei Veterans General Hospital(TPEVGH). There were 5,051 cases of NSCLC, including 168 patients who were <40 years old (younger group) and 4,883 patients aged 40 years or older (older group). It was found younger group had significantly higher EGFR mutation rate than older group (22.6% VS 16.2%, p=0.026), and ALK mutation (4.2% VS 0.5%, p<0.001). Although the younger group had more stage IV patients (60.1% VS 49.6%, p=0.002), they had better (one year:73.7% VS 66.2%, five year:44.4% VS 33.7%) overall survival rate(OS) ( median survival time: 55 VS 26 months ,p=0.002). Regarding histologic subtype, younger group had less squamous cell carcinoma (4.2% VS 16.1% , p<0.001), while adenocarcinoma subtype was similar between two groups (76.8% VS 76.5%, p=0.924). Overall survival rate in younger NSCLC patients were better than the older ones. This survival benefit most likely due to higher EGFR mutation and ALK mutation rate and corresponding TKI treatment. Although more advanced-stage NSCLC patients were seen in the younger group at the same time.