The docs should chime in on this, but I would think that right now as you're fighting the cancer, you don't need the immune-suppression that goes with the androgen crash (I assume you're in the middle of a cycle?).
If it were me, I would consider Hormone Replacement Therapy (HRT) for right now, meaning a minimal replacement dose of test (say 100-150 mg cyp weekly, or 5mg androderm patch ed or 5g androgel ed), plus a theraputic label dose of anavar/oxandrin to battle the cachexia (disease state wasteing) that will accompany the Kaposi's. (so you'd be on HRT-dose test and oxandrin only)
These will help keep your immune system strong till you beat the beast, THEN you can worry about regaining natural Test production (hcg clomid etc or herbal's like avena sativa, trib, maca)
Good luck.