Hey adamo,
Just so you are clear on what Hemosynth does:
your Character is stabbing by a "nuk-it-scorp" For:
4P -4 AP, : Venom (anti-coagulant, instant, 1p/turn <resist stat. not important here>)
You roll your resistance rolls and end up with:
2P damage and poisoned for 1 physical damage a combat turn.
on your pass you inject the Hemosynth:
Because you have a body of 6, it takes 6 Combat turns to infuse.
Because it takes 6 turns, you take an additional 6 points of progressive damage. (for a total damage now of

At the START of the 7th turn, you make a Bodyx2 roll. (you get lucky and get 8 successes!)
you are healed the 6 point of poison damage. (leaving the 2 points from the original attack)
<meaning, 2 of your successes from your bodyx2 roll were wasted>
On YOUR turn in the 7th combat turn, you take 1 point of poison damage. (for a total of 3 physical damage)
<The Hemosynth just resets the damage progressive damage, it does nothing for the actual wound>
And you continue to take 1 physical damage each Combat turn until the conditions to NEURTALIZE the poison are met. (what those conditions are, are spelled out for each type of progressive damage)
As for Cancer:
Cancer, in it's base form, is mutated cells that are rapidly infecting and mutating surrounding cells. The cause of these genetic mutations has been linked to hereditary, environmental, nutritional, chemical, radiological, magnetic, and other factors. 95% of cancers are fatal if left untreated. From symptom/detection to deceased varies, it can be a matter of hours (extreme radiation poisoning) to a matter of years. Short of amputation of all surrounding tissue, there is no known cure for Cancer, there is just regression. (However, Regression periods of years can be achieved)
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See now how some can see what you are suggesting and what is currently known about Cancer as being a good fit as a negative possible consequence?