I don't know. But it looks like currently we do detect it before it spreads, most of the time. So I guess your question has either an answer (e.g. "other sympto

I don't know. But it looks like currently we do detect it before it spreads, most of the time. So I guess your question has either an answer (e.g. "other symptoms manifest sufficiently early"), or an incorrect premise (e.g. "people actually are aware that they should check").