Abstract
BACKGROUND: Recent research into lung cancer-related driver genes has identified a distinctive molecular subtype of non-small cell lung cancer (NSCLC) - anaplastic lymphoma kinase (ALK)-positive NSCLC. We evaluated the clinical features and survival rates of ALK-positive lung adenocarcinoma patients who had undergone surgery but had not received ALK inhibitor therapy, along with the characteristics of patients with distant metastases. METHODS: Clinical data of 40 patients with ALK-positive, postsurgical lung adenocarcinoma were retrospectively analyzed. Relationships between the patients' clinical characteristics, distant metastases, and their disease-free survival (DFS) and overall survival (OS) rates were assessed. RESULTS: Most patients were relatively young, never-smokers, had peripheral tumors, and the tumors were either moderately or poorly differentiated. The most common organ of distant metastases was the brain. The median time from surgery to brain metastasis was 17.2 months. The median OS following brain metastasis was 9.4 months. DFS in patients with early stage disease, peripheral tumors, no lymph node metastases, and treated with adjuvant therapy was significantly longer than for those with late stage disease (P = 0.015), central tumors (P = 0.000), lymph node metastases (P = 0.026), and not treated with adjuvant therapy (P = 0.000). Patients with early stage disease, peripheral tumors, and treated with adjuvant therapy obtained markedly longer OS than those with late stage disease (P = 0.021), central tumors (P = 0.003), and not treated with adjuvant therapy (P = 0.006). CONCLUSION: Patients with ALK-positive surgically resected lung adenocarcinoma have distinctive clinical characteristics. The brain is the most common site of extrapulmonary metastasis. Survival is associated with stage, tumor location, and the administration of adjuvant therapy.