#1 tren itself most (almost certainly) likely did not cause the cancer.
#2 tren may have, both through immune suppression and increased IGF-1, allowed for expression of this retrovirus and may have accellerated its growth.. (note- most cancers are generally theorized to be retroviral in nature)
#3 there is a high correlation between Kaposi's sarcoma and Herpes, HIV and hepatitis.
GlucorellR (R+ lipoic) certainly will help with NFkappa as fonz stated.
for tren related immune suppression(or any AS), the use of pregnenolone, dhea and/or 7oxo may help considerably... as these hormonal precursors (which are suppressed when HPTA is suppressed) are very important to immune health. caps or a topical like PSeven are a good idea.
btw- as a note part of the reason for the development of PSeven was that suppression of the precursors is one of the most overlooked issues with AS use.
lastly... running tren at 300mg a day would be considered excessive.. not to mention that the solvents used in the kits are not particularly healthy either.