I feel really ashamed having to ask questions on here. But I am at an end.  This is the info. 
I have been told someone I know has metastatic sarcoma stage 4.

Started in mouth under tooth that was extracted.  found my dentist. Was seen for a scan at dentist . Then little lump surface level on throat. To 19 cysts all over body, none near organs. Was told it was stage 4 no cure . Has not been offered any treatments only treatment offered are surgeries to remove cysts. This happens weekly/ fortnightly. The hospital they attended don’t offer PET scans. This has been intotal 9 months.  My question is how can you know it’s stage 4 without the PET scan . 
and my other question is if this was true would this be the process this persons very young. Sorry for this post,