I think studies show different average growth rates -- my impression is that as much as .1cm in a year would be considered standard. If it grows .5cm in a year, the recommendation is for surgery.

I had a situation similar to yours. I was at 4.5 when it was discovered, and a second scan one year later showed 4.7. It also made me nervous. The doctor ordered a scan in 6 mos. to look for more growth. The next scan show 4.5 again. I learned that there is a fair bit of error in the measurements (especially with versus w/o contrast). The value depends on lots of factors.

There is data on all the questions you pose. You'll have to dig into the research literature. You can do a Google search for relevant terms and wind your way to papers that try to answer these questions. You can also pose the questions in perplexity. ai, which will give references. I did this after my diagnosis, and I learned (1) the analyses often contradict each other (no surprise there, I guess) and (2) that it's hard for a lay person to get the context that's necessary to understand these well. For example, a paper may give you a relative risk without mentioning the absolute risk. They may give you the risk of death from X, but not mention what the risk of death in general is at a certain age.

That said, I feel the reading was worthwhile for me. I feel like I have an idea of where I stand. Reading the stories of people on this message board has also been very useful. An unexpected benefit of reading myself is that I have a better gauge on whether my doctor keeps up (he does).

I won't give you my interpretation of what I read because I'm not a doctor. The answers are out there, though. I guess I can safely say that after 1.5 years since diagnosis and all the reading, it doesn't enter my mind much. The odds are good in our favor. Now my ridiculously high CAC score is another story. 🙂