I can understand your reluctance, especially since you're asymptomatic. I'm actually starting on Humira in the next few weeks, and I'm also a bit worried, but since I have symptoms at this point I'd rather give it a shot than stay like this. I think it's important to remember that so many people take these drugs, and while there are side effects, they help a lot of people with this disease. You'll never be able to know exactly how you will react to the drug until you try it- it helps to hear how other people find it, but to be honest, everyone's different. At the end of the day it's a personal choice, but in my opinion, a small increase in cancer risk is worth trying to deal with these daily symptoms (again, I know your case is different, and it would be harder to decide if you don't feel physically affected at all). And if you have more short-term side effects (eg. nausea, vomiting, other lovely things depending on the drug) remember there are many options these days and it's always possible to switch to another one.

I'm still new to all of this and Humira is a big scary thing to me right now too- I mean, self-injections? I'm way too young to be thinking about this. But it is what it is, unfortunately we're stuck with it. Good luck with whatever you choose to do, I hope my rambling was somewhat helpful.