My mother had terminal cancer diagnosed during our migration application process. She died two weeks after we arrived in Australia. She was 60.
We'd discussed it and she didn't want to hold us back and I think that would be the case for most. I know I'd never hold back my children in those circumstances.
From a positive angle, I remember her from the last time I saw her, beautiful, fully articulate and outwardly healthy. Not.....well you know.
That was over ten years ago and although I think about it I don't have regrets. This would of course be different for each individual...only you know yourself. As for selfish, well my (at the time) teenage kids hated us for dragging them half way across the world. Swore they'd return to the UK at the first opportunity. They've flourished here and last year the 24YO took me aside and said 'Dad, you were right". There's a first time for everything :-)