55 years and older

Definition of stage I papillary and follicular thyroid cancer (55 years and older)
National Cancer Institute

stage I papillary and follicular thyroid cancer (55 years and older)

(... PA-pih-LAYR-ee ... fuh-LIH-kyoo-ler THY-royd KAN-ser ...)
Cancer is found in the thyroid only and the tumor is 4 centimeters or smaller.

Source: NCI Dictionary of Cancer Terms