With one in 3 people expected to develop some form of cancer in their lifetime I guess it is unlikely that we will ever find a cure for all cancers - but certainly good progress is being made with many forms of cancer. It is incorrect to think of cancer as a disease....because it is actually a large number of different diseases depending on what type of cell it affects. Sadly as life expectancy keeps on increasing as the result of new medical advances and improvements in living standards, the likelihood of developing cancer also increases......but not as much as the likelihood of developing dementia.
It is always hard to lose someone you love or cared for and cancer is a feared word (which is why nurses tend to just call it CA) but with modern medicine and care, cancer may not always be so scary.. for example very few men die of cancer of the prostate nowadays - but it is relatively common. Like most people, I guess, if I could choose how to do it would be in my sleep aged 95 (after making mad passionate love to my wife?) but I think some of the neurological conditions such as Motor Neurone Disease are even more scary than cancer....
I don't mean for this to be dismissive of Gavroche's feelings of anger and loss....life isn't fair and nor is death.