The argument against abortion is that the fetus is a separate person, and thus is not something you do "to yourself."
If we found out cancer cells had souls tomorrow, exactly no one would be screaming “but their souls!” at folks walking into a cancer clinic.
Well, that's a you problem. The rest of us make decisions based on what we believe, not on what you believe.
I would hope most people have enough self awareness to not compare a foreign hostile disease that does nothing but kill its host to a human life.