How long in situ adenocarcinoma patients can live is generally not generalizable and should be analyzed according to patients’ specific conditions. Generally speaking, if detected early, the five-year survival rate after radical surgery can reach more than 95%, but if the best treatment time is missed, the five-year survival rate is about 60% or even lower, so it is recommended to seek medical treatment in time. Adenocarcinoma in situ is a stage of lung adenocarcinoma without infiltration and metastasis. If detected in time, most of the adenocarcinoma in situ can be cured by radical surgery, with a five-year survival rate of more than 95%, and the patients have a better prognosis. However, if the best treatment time is missed, adenocarcinoma in situ may progress to invasive adenocarcinoma, and once it spreads and metastasizes, it needs to be treated by surgery, together with targeted drugs, chemotherapy, radiotherapy and other modes of comprehensive treatment, to prevent the recurrence of the tumor. Therefore, it is not possible to generalize how long in situ adenocarcinoma patients can live. In general, patients should pay attention to reasonable diet, strengthen nutrition, eat more vegetables and fruits, and avoid spicy and stimulating food. It is suggested that patients should find out the disease as early as possible and seek medical treatment, and follow the doctor’s instruction to treat the disease actively.