Hi, Thanks for writing in. Cancer is a difficult disease to treat but many have survived even after having stage 3 squamous cell carcinoma and you should not give up. Praying to God for your quick recovery. Chemotherapy is a method used in treating cancer by infusion of medication that act only against cancer cells. This causes reduced growth and tumor volume. The best way to make sure that cancer treatment is working is by comparing CT scan of the region at the start of treatment and 3 to 6 months after treatment. This will tell the exact reduction in tumor volume and lymph nodes that are present in the cancer area. This is followed by most doctor and it can be used to guide treatment. Every cancer has a 5 year survival rate. In your case it does not mean that you will survive only for 2 years but the doctor means to say that with a tumor that you have, survival in some people is limited to around 2 years. I wish your tumor will respond to treatment and you will have a longer than expected disease free survival. Please do not worry.