<s>[INST] My brother who is a recovering addict and has COPD has been diagnosed with small cell lung cancer. They say it is limited stage, but he is presenting with a lot of symptoms. He has started Chemo 3 days a week and then again in 2 weeks with radiation every day. Realisticly, what are his chances of survival? [/INST] Small cell lung cancer is a very aggressive disease. The tumor responds initially well to chemotherapy and radiation therapy witChatDoctorplete responses (no evidence of disease on repeat CTs caning) in 45 to 60 % of limited stage disease patients. But it has a tendency to relapse in the mediastinum (the central compartment between the two lungs) and in the brain. That is why after completion of his chemo radiotherapy to the thoracic (chest) disease, your brother will be given prophylactic cranial irradiation (PCI) to prevent relapse in brain. The 5-year survival rate of limited stage SCLC is 25%, meaning one fourth of the treated patients of limited stage disease would be alive at 5 years. I hope I have answered your query. If you have any further questions I will be more than happy to answer. Wishing your brother a rapid recovery and good health. </s>