Age and smoking intensity in non-small cell lung cancer patients with the anaplastic lymphoma kinase fusion gene.

Introduction: It is widely accepted that anaplastic lymphoma kinase (ALK) fusion gene-positive non-small cell lung cancer (NSCLC) patients are more likely to be in their 50s, female, and non-smoking. This seems to be due to the background of patients involved in clinical trials of ALK-tyrosine kinase inhibitors. However, in daily clinical practice, it is not uncommon to encounter elderly ALK-positive NSCLC patients with a smoking history. In light of this background, we conducted a survey to clarify the clinical backgrounds of ALK-positive patients with NSCLC, particularly regarding age and smoking. Material and methods: A retrospective medical chart survey of patients with ALK-positive NSCLC diagnosed in 2012 to 2024 in our six institutes was conducted. Results: During the study period, 140 pa-- tients were diagnosed with ALK-positive NSCLC, of which 90 (64.3%) were women. The median age of all 140 pa-- tients was 63 years (range, 26-84 years). Among these 140 patients, 38.6% had a history of smoking. There was a significant difference in the distribution of smokers by sex and age. Conclusions: Even among NSCLC patients who are elderly or have a history of smoking, there may be some who miss out on the best possible treatment by exclusion from ALK testing. Discussions considering the efficiency and cost of testing are needed, and it is essential to collect and reanalyse as much information as possible about the clinical characteristics of ALK-positive NSCLC patients.