How long does stage iv nsclc response last?

Very variable: May factors are involved in response to therapy, and patients with stage 4 lung cancer are a diverse lot. Some patients respond well to therapy, but then relapse within weeks to months. Others go on for a while. Unfortunately the majority of patients with this diagnosis survive less than a year.

Survival is very bad: Since most patients are dead within a year, the response is generally not long. It is, however, very variable. I hope this helps.