Comparison of clinicopathological and molecular features between young and old patients with lung cancer

Objective: To investigate whether features of lung cancer in young patients differ from those of elderly patients. Method: A retrospective analysis was made to compare clinicopathological and molecular characteristics between 272 young patients under 40 years old (young Group) with lung cancer and 167 elderly patients over 60 years old (elderly group). Results: The young group had significantly higher proportions of females, adenocarcinoma, and were well differentiated, without lymph node metastasis, and were of lower clinical stage as compared with the elderly group (P<0.05). The positive rate of ALK in the young group was significantly higher than in the elderly group (17.01% vs. 4.17%, P<0.05), but there was no significant difference between the mutation rate of EGFR and ROS1 in two groups. However, the distribution of EGFR mutation sub-types in the two groups was significantly different, with the proportion of 19del in the young group being significantly higher than that in the elderly group. Conclusions: The young patients with lung cancer have distinct features compared with elderly patients, and may have different mechanisms of tumorigenesis.