Question: How do people get cancer and can it get passed down, for example, if a parent has cancer then does that mean one of his children can be a carrier of cancer as well?

Christina Pagel answered on 17 Jun 2013:

I’m no expert in cancer, but I do know that there are lots of different types of cancer and they can happen for different reasons…

some cancers are just random bad luck – some of your cells start growing abnormally and take over and that’s cancer – and there’s no reason.

Some cancers come about through unhealthy lifestyles or environmental factors – for isntance asbestos used to be used in building because it doesn’t burn. But it turns out it causes lung cancer in people exposed to it – so it’s now banned in the west. Smoking too can cause lung cancer. That sort of thing can’t be passed down from parent to child.

But there are some cancers that are genetic – so that if you have a certain set of genes you are much much more likely to develop cancer. So there are some genes that make breast cancer much more likely (these are the genes that Angelina Jolie has and why she recently had her breasts removed). For these cancers, those genes can be passed down from parent to child.

But I think that such genetically influenced cancers are less common that lifestyle or random cancers… but maybe a medical expert would correct me on that!