Hypothetical Life or Death

[Henry]

The situation goes something like this...

A guy has bone cancer in his appendage, or limb. Option 1 is to cut it off, guaranteeing survival and the cancer will not return. Option 2 is a refusal to cut it off, realizing a x% chance that the cancer will dissapear completely, and a y% chance the cancer spreads causing slow and certain death.

What's the lowest % chance at survival the guy realizes, while still choosing option 2, for a:

Pinky finger
Index finger
Thumb
Hand at wrist
Arm at elbow
Arm at shoulder

Toe
Big toe
Foot at ankle
Leg at knee
Leg at groin
Everything below belt line

[Belly Buster]

I'd set my line at 5% and chop off whatever was needed to keep below that %, up to a max of one limb. I think you can lead a pretty normal life with one limb missing.

"Everything below the belt" wouldn't figure, I'd take my chances rather than do that.