The film Surviving Terminal Cancer suggests this failure is due to a flawed approach the medical establishment has towards terminal disease. The film covers a number of individuals that have been diagnosed with terminal cancer and in many cases given just months to live. Many of the individuals are still alive today (10 or 15 years later). The reason they are still alive is by ignoring the advice of their oncologists and self administering a cocktail of drugs. This practice has been shown to be effective against HIV but for other terminal diseases is difficult and often illegal.
The film highlights how the patients best interests and the the best interests of science are often at odds especially in cases of terminal disease.