an early stage
consult a doctor at an early stage of an illness／have one's illness diagnosed early (on)
早期退職者｜an early retiree
The company is recruiting employees who would be willing to take early retirement.
an early-retirement incentive plan
get early treatment／be treated by a doctor at an early stage of an illness
Early detection [discovery] is of vital importance for the successful treatment of cancer.
早期発症型認知症｜early onset dementia