If you read Andreas Moritz book on cancer, he believed that cancer is not something going wrong in terms of cell replication or that you have some predisposition to a disease.
He believed that a cancer cell was deliberately created from a normal cell to deal with a last resort situation which would have dire consequences. So basically if are toxic your lymph nodes would reach a stage where they could no longer deal with the toxicity and reach a critical point. The body then creates a cancer cell that basically deals with the area in the body with the toxicity.
The imbalance in your body could be created even by emotional responses, since you can get a raise in cortisol and your parasympathetic nervous system could shut down resulting in chronic stress and lack of digestion etc. There could also be environmental considerations to cause it too. The bottom line is you need to also find the underlying cause of the cancer in addition to your treatments. Once you remove that, the cancer will have done its job and the body no longer needs it.
One thing I will mention w.r.t. predisposition is you inherit your genes from your parents. The apple doesn't fall far from the tree. However, if a parent acquired cancer due to some specific gene expression, to assume you will acquire this condition isn't generally a good train of thought. Genes express proteins, and these proteins are used throughout your bodies processes. However, eating different foods (for example switching to a diet skewed in vegetables) will access different genes and hence express different proteins. There's also epigenetic factors you need to consider. Even if you had the same activated genes as your parents, the effects of epigenetics can still cause a different gene expressions. Epigentics is in layman's terms is something that lies on top of your DNA that can change due to your environment which affects expression.
en.wikipedia.org/wiki/DNA_methylation
So, in a nutshell, you do not have a predisposition that is set in stone which seals your fate. Detox your body, sort your diet out, get some moderate exercise, do not take drugs, get a good sleep, cut down sugar, consider intermittent fasting and drink enough water. These all decrease your chances of having cancer or some life changing disease.