I replaced my cam chain at 76,000 miles (122,000 Km if my math is correct). I noticed a definite rattle from the top of the engine and a drop in performance. The cam chain had stretched but the bigger issue was the chain tensioner blade had worn down badly. I replaced the chain and tensioner blade at the same time. It's a tricky job but not rocket science. I just followed the shop manual and was really
careful and it all went smoothly. The difference was apparent immediately.
But at only 75,000 Km (or 46,000 miles) I think, unless the engine has been constantly abused, you shouldn't need one just yet. To check it remove the valve cover and inspect the cam chain tensioner and blade. If the tensioner is fully extended and there is still slack in the cam chain then yes you need to replace it but I seriously doubt it given your mileage.
Stretched cam chain top, new chain bottom
Worn tensioner blade left, new one right
Shiny new cam chain installed
good luck, feel free to ask me more questions,