By last stage, I assuming that you mean stage 4 cancer.
In the past few decades survival rates have significantly improved in cancer treatments.
Depending on the cancer type, location, age of the patient, etc you get a good understanding from your doctor about the chances of survival.
The only point here is that the treatment would likely continue till the time patient responds to treatment.
There are many examples of patients who lived for several years while being treated for last stage cancer.
Given below is a graph that shows the 5 year survival rate of different types of cancer and we see that there is improvement in the right direction for all cancer types
Image source: Our World In Data
Data suggests that the tumors have gotten smaller and the early detection has improved over the past few decades.
However, after adjusting for the early detection and size of the tumor there is still improvement in the overall 5 year survival.
I short, Yes, there is hope for someone with last stage cancer.