Moving as an only child when parent is ill

Just got an offer to relocate to another side of the world - US. Thinking to go for a year or so (thats when i have to re apply for the visa). My mum has stage iv cancer, on medication, pretty stabilised but with cancer, its always unpredictable right? I feel the guilt of moving so far away even though we are not close. She brought me up but we dont really talk or bond. Maybe its the asian filial piety mindset thats weighing me down even though i think i should go for an amazing career and personal growth opportunity.

Im not sure if this opportunity would come again since im in my late 20s and as im older and would like a family, i wouldnt move to the US to do so. Now I’m free from commitments except my parents. Thinking of going but fly back often even though its far and expensive. Any insights or advice from anyone who has faced this?