The attempt of alternative medicine is to restore this balance. When the balance is restored, the person is "cured" of their cancer because they have a strong enough immune system to handle the number of cancer cells in their body.
Orthodox medicine does not like people using the word "cure." The reason is that orthodox cancer treatments destroy a person's immune system and thus the patient can never restore the balance between the number of their cancer cells and the strength of their immune system.
Their definition is designed to glorify treatments that convert cancer into a chronic disease (i.e. the patient has no immune system). Increasing the percentage of patients who live for 5 years is more of a reflection of their profit motives than the effectiveness of their treatments.
Alternative cancer treatments can actually have one of three different outcomes:
First, are those who never get cancer again because their cancer cells have been killed, or reverted into normal cells, and their immune system has been built up and their lifestyle has changed.
Second, are those who have the vast majority of their cancer cells killed or reverted into normal cells, but for one of many different reasons, such as going back to their old lifestyle, the cancer does return. In this case, there is a high probability that they will know what to do the second time around.
Third, are those who do not survive their cancer. This can happen because the wrong treatment was chosen or prior orthodox cancer treatments did irreversible damage. In any case, it is almost certain that the alternative cancer treatments improved and extended their life far beyond what orthodox medicine could have done.
Orthodox medicine has had many opportunities to establish treatments that cured cancer (using the alternative medicine definition of "cure"). In every case they have rejected such treatments in favor of far more profitable treatments. In fact, the choice of orthodox medicine for their definition of "cure" is designed to hide the fact that they have no desire to actually "cure" a cancer patient using the alternative definition of cure.
The goal of orthodox medicine is to convert a cancer patient into a long-term profit center (i.e. they wish to turn cancer into a chronic disease), such as they already do with diabetes patients. Their definition of "cure" reflects this desire and their desire to "look good" to the public. Orthodox medicine frequently uses clever definitions to hide their real goals and the ineffectiveness of their treatments.