Hi again, I'm afraid I can't PM you ( perhaps if it's 'cos you are "on probation?").
I'll simply say I've known at least two people at work in their late 50's who were happily passing Class Ones but discovered they had malignant tumours during routine Health service screening (happily both have since recovered)....
The medics will know the ins and outs and pros and cons of this so their views will be interesting - as you are obviously aware there are risk factors to some screening methods.