Lung metastases formed by disseminated tumor cells exhibit different proliferation states

• Disseminated tumor cells (DTCs) in the lungs exhibit heterogeneous proliferation states, including active proliferation and dormancy, which may explain late metastasis after primary tumor removal. • Using a mouse model with CTC-TJH-01 cells, DTCs were found to spread evenly in the lungs within 24 hours, but after 12 weeks only a few visible metastases formed, with many single DTCs remaining Ki67-negative (dormant). • The coexistence of metastases with different proliferation rates suggests differential responses to radiotherapy and chemotherapy, potentially impacting treatment efficacy in early-stage lung cancer patients. • The concept of a 'metastasis subclinical stage' and the TCM theory of 'hidden toxicity due to vital Qi deficiency' provide a framework for early intervention and personalized metastasis prevention strategies.