[overthemoon]

Why does tissue damage increase the risk of cancer? My guess is that more damage -> more cells created to replace damaged ones -> more opportunities for mutation. Is that right? If you bite the inside of your lip a lot, is that bad? Uh, asking for a friend.

[Cerium]

When you have damaged tissue you must replace it sooner. Tissue replacement is by division of cells, which carries the risk of a transcription error. If the wrong error occurs and is not caught you have cancer.

[epgui]

Basically this, but perhaps a slightly more accurate explanation is that tissue damage causes inflammation, which is angiogenic, proliferative (which you hint at) and generally increases the risk of cancer.

[yamtaddle]

> If you bite the inside of your lip a lot, is that bad?

Yeah, um, gonna want an answer to that too.

This:

https://en.wikipedia.org/wiki/Morsicatio_buccarum

Makes no mention of cancer risk even in fairly extreme cases of cheek-biting.

The "Oral Cancer" article also doesn't list it as a risk factor or cause.

So... probably not that bad?

[epgui]

Yes, constantly biting your lip (I’m talking about injuring the tissue, not just nibbling) will increase your risk of oral cancer too.

It’s not something most people do super often, so I’m not sure if we’d even have a risk measurement for that. In almost all cases of accidental biting risk is basically nil / negligible… But theoretically nonzero.

A reference (somewhat taken at random) for more explanations of the general concept: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803035/

It’s a well-established principle, and is one of the main reasons why smoking anything in general will cause lung cancer, why hepatitis frequently leads to liver cancer, why IBD frequently leads to bowel cancer, why alcohol consumption causes oral cancer, etc.