Regarding efficiency of chemotherapy

From here:

At least two thirds of people with advanced cancer in a new survey believed the chemotherapy they're receiving might cure them, even though the treatment is only being given to buy some time or make them comfortable.

When lung cancer or colorectal cancer has spread, chemotherapy may extend survival for weeks or months at a cost of some substantial side effects.

This is very sad but true. The reality is harsh. No cures, no magic bullets.