Blood test removes all doubt, a problem is GPs can be wrong and...

Blood test removes all doubt, a problem is GPs can be wrong and they’re reluctant to order diagnostic imaging in the absence of certain criteria. Even if they do give you a referral for something as simple as an ultrasound, there are parts of the country where you could be waiting months even in metro areas, this is less of an issue for pathology as blood sampling is pretty low tech. While it may not tell you which cancer, it indicates an urgency for further testing and relieves strain on more specific diagnostic resources.