Body parts which heal faster tend to be more prone to cancer.
The faster a body part heals irl, the more prone it is to cancer. This is because every time it regenerates there is a chance it goes wrong and gets cancer.
The more a vampire regenerates a body part, the more chance of cancer
Every time their body regenerates it will accumulate more and more mutations which risk damage. As such, the good guys have the option of just repeatedly cutting off or destroying body parts, so gradually the vampire will have massive tumours in any regenerated body parts.
This would also depend on how good their genetics were
Strong genetics might make them more resistant to mutations or damage, with cancer suppressing genes being more effective. You could represent this with bloodlines. A big boss vampire might have a stronger bloodline and be more resistant to tumours, while a basic vampire would have a weaker bloodline and easily get tumours.