The rest of the world can thank people in the US for spending rather large sums on certain treatments. In the UK the treatments are covered by the state at no

The rest of the world can thank people in the US for spending rather large sums on certain treatments. In the UK the treatments are covered by the state at no cost to the patient, but it's only a limited set of available treatments which are considered cost effective. In the US there are plenty more options, if you can pay for it. People may decide to bankrupt themselves or sell their house for these treatments that could enable them to survive or not, but either way they are contributing to real world data that informs the rest of the world of the efficiency and cost effectiveness of a particular treatment.