Energies for both (described earlier):
--- Dampness for structure and Dryness/Dampness for the tissue it's roots in, for sarcoma
--- Cold for structures (dense tumour) and Dryness for epithelium for cancer.
From Su-jok theory a disease to be life-threatening seemingly needs to have a grip on at least Practical controlling level i.e. Cold - Burn level:
Less fundamental pairs like Heat-Dryness and Wind-Dampness seem not able to create energy disruption severe enough to directly threaten life:
--- Heat-Dryness is ulcer formation, various spasms, degenerative conditions etc.
--- depression as emotional/mental Heat-Dryness disorder can lead to suicidal thoughts but it is not what directly causes critical damage of body like cancer does.
Cancer shows clear presence of Cold as structures and Burn as spreading.
Sarcoma spreading is also Burn energy, however the Cold energy is not clearly seen.It seems sarcoma is more sophisticated disease for it's origin and mechanisms, going together with it's being less explored in general.
Anyway, since it is the same life-threatening, it is to be viewed as disorder on Cold-Burn level regarding this aspect for acupuncture schemes, and treated similar to cancer.
As for structural aspects, emphasis seems to be put on Dampness energy in connection to what organ
or tissue is has striken.