There is no need to cancel your title insurance. It's a one time premium.
The loan policy will automatically cease when the mortgage is paid off.
The owner policy will stay in effect and protect you for as long as you have an interest to defend. It even survives the sale of the property. If you sell the property and at some point you are contacted by someone with a claim related to issues that would have been covered under your policy, the title insurer will STILL defend you even though you no longer own the property. This is because title insurance insures backwards. So if the issue in question occurred before the policy was issued and you are at risk, contact your title insurer to see if it's covered