In Ontario, routine self-referral screening runs from age 40 to 74. After 74, the program stops automatically inviting you, but screening can continue if you’re in good health and want to — that’s a conversation with your doctor, not an automatic stop. Under 40, routine screening isn’t offered for average-risk women, but high-risk women may start as early as 30, and any new symptom at any age should be checked right away.